A&P LAB 4

Anecdotal, Correlational, or Circumstantial Evidence

"Where there is smoke, there is fire" is a popular saying. When two things occur together frequently, it is possible to assume that there is a direct or causative relationship between them, but it is also possible that there are other factors. For example, if you get sick every time that you eat fish and drink milk, you could assume that you are allergic to fish. However, you may be allergic to milk, or only to the combination of fish with milk. Correlational evidence is good for developing hypotheses that can then be tested with the proper experiments, e.g., drink milk only, eat fish only, eat fish and milk together. There is nothing wrong with using representative cases to illustrate an inductive conclusion drawn from a fair sample. The problem arises when a single case or a few selected cases are used to draw a conclusion which would not be supported by a properly conducted study.

Regardless of their specific anatomical form, all sense organs share basic features:

(1) All sense organs contain receptor cells that are specifically sensitive to one class of stimulus energies, usually within a restricted range of intensity. Such selectivity means that each receptor has its own "adequate" or proper or normal stimulus, as, for example, light is the adequate stimulus for vision. However, other energies ("inadequate" stimuli) can also activate the receptor if they are sufficiently intense. Thus, one may "see" pressure when, for example, the thumb is placed on a closed eye and one sees a bright spot (phosphene) in the visual field at a position opposite the touched place. (2) The sensitive mechanism for each modality is often localized in the body at a receiving membrane or surface (such as the retina of the eye) where transducer neurons (sensory cells) are located. Often the sensory organ incorporates accessory structures to guide the stimulating energy to the receptor cells; thus, the normally transparent cornea and lens within the eye focus light on the retinal sensory neurons. Retinal nerve cells themselves are more or less shielded from nonvisual sources of energy by the surrounding structure of the eye. (3) The primary transducers or sensory cells in any receptor structure normally connect (synapse) with secondary, ingoing (afferent) nerve cells that carry the nerve impulse. In some receptors, such as the skin, the individual primary cells possess threadlike structures (axons) that may be yards long, winding from just beneath the skin surface through subcutaneous tissues until they reach the spinal cord. Here, each axon from the skin terminates and synapses with the next (second-order) neuron in the chain. By contrast, each primary receptor cell in the eye has a very short axon that is contained entirely in the retina, which synapses with a network of several types of second-order neurons called internuncial cells, which, in turn, synapse with third-order neurons called bipolar cells—all still in the retina. The bipolar-cell axons extend afferently beyond the retina, leaving the eyeball to form the optic nerve, which enters the brain to make further synaptic connections. If this visual system is considered as a whole, the retina may be said to be an extended part of the brain on which light can directly fall.

discriminatory vs emotional

A distinction between the discriminatory (epicritic) and emotional (protopathic) features of sensations was made by Sir Henry Head (1861-1940), a British neurologist who noted that after a sensory nerve from the skin had been cut, the first sensations to recover as the nerve healed appeared to be diffuse and extremely unpleasant. Head theorized that this initial lack of sharp discrimination associated with unpleasant experience reflected the properties of a primitive protopathic neural system that regenerated first. He held that this system subserves pain and the extremes of temperature and pressure sensation usually associated with an affective (emotional) tone. Because recovery of fine tactile discrimination, sensitivity to lightly graded stimuli, and the ability to localize points touched on the skin returned later, Head posited the existence of another discriminatory system. While later research has not confirmed his theory, the sequence of changes in the recovery following nerve injury is most typical.

testimonial evidence

A famous football player appears on television and says that Drug-XYZ provides relief from pain and works better than anything else. You know that the football player gets paid for making the commercial. How much can you trust this evidence? Not very much. Testimonials are often biased in favor of a particular point of view. In court proceedings, something actually experienced by a witness (eyewitness information) has greater weight than what someone told a witness (hearsay information). Nevertheless, experiments have repeatedly demonstrated that eyewitness accounts are highly unreliable when compared with films of the events. The statement "I saw a ghost last night." is an example of testimonial evidence that probably cannot be verified and should not be trusted. On the other hand, the statement "I saw a car crash yesterday." can be objectively verified to determine whether it is true or false by checking for debris from the accident, hospital records, and other physical evidence.

types of evidence

Evidence is something that provides proof concerning a matter in question. Direct or Experimental evidence. Anecdotal, Correlational, or Circumstantial Evidence Argumentative Evidence Testimonial Evidence.

salt

Although saltiness is often associated with water-soluble salts, most such compounds (except sodium chloride) have complex tastes such as bitter-salt or sour-salt. Salts of low molecular weight are predominantly salty, while those of higher molecular weight tend to be bitter. The salts of heavy metals such as mercury have a metallic taste, although some of the salts of lead (especially lead acetate) and beryllium are sweet. Both parts of the molecule (e.g., lead and acetate) contribute to taste quality and to stimulating efficiency. The following is a series for degree of saltiness, in decreasing order: ammonium (most salty), potassium, calcium, sodium, lithium, and magnesium salts (least salty).

taste aversion

Among adults, past experience strongly influences eating habits, sometimes to the point that physiological well-being suffers. Food habits and other factors play a significant role in eating behaviour. Taste alone is not a reliable guide to safety. Poisonous substances often are unpalatable, but not invariably. Lead acetate, sometimes called sugar of lead, once was used as a sweetening agent with disastrous results before its potentially fatal effects were discovered. Many palatable substances, including some synthetic sweeteners, are toxic. Taste aversions may be established by conditioning, even for substances that have been previously preferred. In one study, a rat tasted saccharin solution three hours before being exposed to enough radiation to become sick. When the animal recovered, it was found to have a strong aversion to the taste of saccharin. Other aversions selectively can be produced by injecting an individual with a nauseating drug before or after a specific taste experience. For example, the medication disulfiram (Antabuse), used in the treatment of alcoholism, reacts with alcohol to produce nausea and vomiting. An unusual finding is that long delays of up to several hours in the time between the presentation of the taste stimulus and the induction of illness do not prevent the conditioning. In most other studies, only brief intervals (perhaps up to minutes in duration) have been found to result in successful conditioning. Positive preferences also are subject to conditioning, as when the tastes of drugs or vitamins become associated with the feelings of well-being they generate.

fallacies

Arguments are subject to a variety of fallacies. A fallacy is an error in reasoning in which the premises given for the conclusion do not provide the needed degree of support. A deductive fallacy is a deductive argument where the premises are all true but reach a false conclusion. An inductive fallacy consist of arguments where the premises do not provide enough support for the conclusion. In such cases, even if the premises are true, the conclusion is not likely to be true. Common fallacies are categorized by their type, such as Ad Hominem (personal attack), and appeals to authority, belief, fear, ridicule, tradition, etc. An example of an Ad Hominem fallacy would be to say "You do not understand this because you are American (or Chinese, etc.)". The national origin of a person (the premise) has nothing to do with the conclusion that a person can understand something or not, therefore the argument is flawed. Appeals to ridicule are of the form: "You would be stupid to believe that the earth goes around the sun". Sometimes, a naive or false justification may be added in appeals to ridicule, such as "we can plainly see the sun go around the earth every day". Appeals to authority are of the form "The president of the United States said this, therefore it must be true". The fact that a famous person, great person, or authority figure said something is not a valid basis for something being true. Truth is independent of who said it.

Anatomy and Structure of Human Sense Organs

Aristotle (384 BC - 322 BC) is credited with the traditional classification of the five sense organs: sight, smell, taste, touch, and hearing. As far back as the 1760's, the famous philosopher Immanuel Kant proposed that our knowledge of the outside world depends on our modes of perception. In order to define what is "extrasensory" we need to define what is "sensory". Each of the 5 senses consists of organs with specialized cellular structures that have receptors for specific stimuli. These cells have links to the nervous system and thus to the brain. Sensing is done at primitive levels in the cells and integrated into sensations in the nervous system. Sight is probably the most developed sense in humans, followed closely by hearing.

Cutaneous (skin) senses

As noted above, studies of cutaneous sensitivity yield evidence that the human senses number more than five. There is evidence for two pressure senses (for light and for deep stimulation), for two kinds of temperature sensitivity (warm and cold), and for a pain sense. In the 1880s, findings that the human skin is punctate (selectively sensitive at different points) gave clear indication of a dissociation among functions once grouped together as the sense of touch. Mapping the skin with a fine bristle or with a narrow-tipped (warm or cold) cylinder showed that there are different spots of maximum sensitivity to pressure, warm temperatures, and cold temperatures. When stimulated between the spots on the skin, no such sensations were reported. Pain spots also can be located with a finely pointed needle, but the punctate character is less striking since pain seems to be widespread when stimulus intensity is increased. The number of spots is greatest for pain, next for touch, then for cold, and least for warm.

verbal outputs

As was mentioned in the previous chapter, verbal communication is more than just sounds. Words convey mental images to our listeners. What we say or what we imply changes the listener. The way in which we say something also carries a message. The use of a rich vocabulary may imply wisdom or snobbishness, forcefulness indicates conviction, and hesitation represents insecurity. Songs and rhymes are special forms of ritualized communication. Before writing was invented, oral history was the only way to pass information from one generation to the next. Poems and songs were particularly effective at passing information, because they could be learned at an early age, even though they might not be understood until much later.

bacteria and viruses

Bacteria and viruses come into the body principally through the eyes, the mouth, the skin, and the nose. Some bacteria actually have a beneficial effect. The "normal flora" that are found in the mouth release substances that prevent more harmful bacteria from getting established. Other bacteria aid in digestion or produce vitamins and nutrients that the body can use. Bread, yogurt, beer, wine, vinegar, and many types of cheeses are produced by using specific types of non-harmful yeasts, bacteria, or fungi. Disease-causing bacteria release toxins that interfere with normal body processes. Viruses, which are much smaller than bacteria, work against the body by re-directing the synthesis of normal cell components into replication of the virus. The body tries to fend off bacteria and viruses by generating chemical antibodies and by increasing body temperature. Fever creates a more hostile environment for bacteria but can result in delirium and other forms of mental changes. Some diseases like rabies or polio attack directly the nervous system. Learn more about Bacteria and Viruses.

chemical-visceral sensations

Chemical-visceral sensations particularly have hedonic (pleasure-pain) properties. Most people tend to refer to odours and tastes as pleasant or unpleasant; thus, the chemical senses are closely tied to motivations, preferences, and aversions. Although reflex licking or sucking is stimulated by tactile stimulation of the lips and mouth, newborns tend to suck longer and harder when the stimulus has clear hedonic value—e.g., avidly turning their lips toward a nipple for a sweet taste. Apparently, one's "sweet tooth" is largely nativistic, in that it requires little prior learning. The craving for salt (especially heightened under conditions of salt deprivation) likewise appears to be nativistic. The role of taste and smell as innate factors in behaviour may not be quite so influential in humans as in other animals. People's food habits and preferences are strongly related to custom and tradition; that is, they are primarily learned.

color blindness

Color blindness or "Daltonism" is a common abnormality in human vision that makes it impossible to differentiate colors accurately. One type of color blindness results in the inability to distinguish red from green. This can be a real handicap for certain types of occupations. To a colorblind person, a person with normal color vision would appear to have extrasensory perception. However, we want to reserve the term "extrasensory perception" for perception that is beyond the range of the normal.

clear your mind

Clear your mind and try not to think of a circus elephant. Are you visualizing a circus elephant anyway? If you imagine that you ride on top of the elephant can you see the ground? Do you feel the wobble as it walks? Mental simulations such as this, can create mental images that can be reinforced by adding realistic detail, such as times, dates, smells, etc. There may come a time when some individuals may actually think that they remember riding a circus elephant even if they never have. Techniques like these can be used to plant memories or to modify behavior. False memories and specific behavior may be induced in a person subjected to stress, sleep deprivation, or other stimuli that may trigger Pavlovian responses. You are touring a country where you have never been before, and all of a sudden, the place where you are seems familiar, as if you had been here before. That is déjà vu. What triggers these memory episodes? Was it a childhood experience? Was it a magazine that you read? Was it a movie that you saw? The answers can never be determined externally. Your memories are only yours and not shared by anyone else. Psychologists have set up experiments where they position several witnesses in a location where an incident is staged. Then they ask the witnesses to report what they saw. Witnesses frequently make mistakes in the events and the sequences of events that they report. If the interrogators provide the witnesses with photographs of events that actually happened and events that were staged at a different time, sometimes the witnesses will say that they "remember" events that they did not actually see. Memory decays with time. The longer the time elapsed between an event and when we recall it, the less vivid and less detail that we will remember.

sounds

Coughing, sneezing, breathing, and heartbeats are sounds output by the body. There are also mechanical noises such as clapping and whistling, but by far, the most important sounds are produced through singing and verbal communication.

dermatomes

Each of the nerves distributed along the spinal cord contains a sensory bundle that serves a well-defined strip of skin (a dermatome) about 2.5 cm (1 inch) wide or more on the body surface. Successive spinal nerves overlap, so that each place on the skin represents two and sometimes three dermatomes; this yields a segmented pattern of strips over the body from head to toe. All dermatomes feed into a single relay centre (the sensory thalamus) deep within the brain, where there is a precise three-dimensional layout of tactile sensitivity at the body surface. The neurons in this part of the thalamus (the ventral posterolateral nucleus) are specific to particular skin senses (such as pressure) and form small and precise receptor fields. Pathways from the specific ventral posterolateral thalamus end (or project) in a narrow band of the cerebral cortex (the posterior rolandic cortical sensory area) where there is a point-for-point representation of the body surface on the cortical surface. There is a second more diffuse thalamic system (in the posterior thalamic nuclei) where the receptor fields are large, perhaps bilateral, on the left and right sides, perhaps including one whole side of the body. The receptor fields here and the types of stimuli to which they respond are not clearly delineated. The cortical projection of the posterior thalamic system is less well charted than that of the ventral posterolateral thalamus. Thus, there appears to be a dissociation between tactual structures that are highly specific and those that are more generalized.

olfactory bulb

Electrical activity can be detected with fine insulated wires inserted into the olfactory bulb. Portions of the olfactory bulb toward the anterior or oral region in the rabbit are found to be more sensitive to water-soluble substances, whereas the more posterior parts of the olfactory bulb are more sensitive to fat-soluble substances. In addition, when very fine electrodes are used, individual cells (mitral cells) are sensitive to different groups of chemicals. Evidence for the existence of only a few primary receptors, however, does not emerge from such studies; a variety of different combinations of sensitivity has been found. Similarly, recordings from the primary receptor nerve fibres reveal different patterns of sensitivity. Electrical recording of this type also shows that olfactory sensitivity can be enhanced by a painful stimulus, such as a pinch on the foot. This appears to be a reflex that serves to enhance the detection of dangerous stimuli in the environment. Different parts of the olfactory neural pathways seem to be selectively tuned to discriminate different classes of olfactory information. For example, the third- and fourth-order olfactory neurons found beyond the olfactory bulb of the rat seem particularly concerned with distinguishing the odour of sexually receptive females. These neurons appear to be especially important in the preference the male rat shows for the smell of urine from the female in heat

radiation/light

Electromagnetic radiation can be good and it can be bad for the body. It depends on the type of the radiation and the duration of the exposure. Infrared radiation, which is low-frequency radiation, is felt as heat. Sitting by a fireplace or a pot-bellied stove on a cold winter night can feel comforting without any harmful effects. Excessive doses of infrared radiation can result in burns. Normal skin produces Vitamin D when exposed to sunlight for brief periods of time. When exposed for long periods of time, the skin reddens and becomes painful to the touch. Repeated exposure to sunlight stimulates the skin to produce a protective dark pigment called melanin. Chronic exposure to sunlight eventually breaks down the cellular structure of the skin and can result in wrinkling, cancerous melanomas, or other skin disorders. The amount of light to which the body and eyes are exposed may affect the central nervous system. Seasonal Affective Disorder (SAD) is a form of depression that includes feelings of sadness, tiredness and cravings for carbohydrates. It is believed to be related to the decreased sunlight in winter and the release of melatonin. Melatonin is usually produced by the pineal gland at night and induces sleep. Besides sunlight, the body may also be exposed to moonlight, which is sunlight reflected off the moon. The light of the moon is weak, but it enabled early humans to have some nighttime activities before the invention of fire and artificial lighting. The word "lunatic" is derived from the Latin for "moon". At one time it was believed that the influence of the moon triggered mental disorders. The use of artificial lighting has introduced some problems that did not exist before its invention. Some people are sensitive and can get headaches from the flickering of fluorescent lights. The flickering is particularly noticeable in the peripheral vision. Flashing images from television or strobe lights can also cause harmful effects to the nervous system and can trigger seizures. A Japanese television cartoon program that used flashing pictures to simulate an explosion sent several hundred children to the hospital with various neurological symptoms. High-energy radiation such as ultraviolet light, X-rays, or Gamma rays can destroy cells. X-rays and Gamma rays have greater penetration than ultraviolet light and are used medically for diagnostic imaging and to burn tumors. Ultraviolet lights, also called "black" lights, are used in hospitals and grocery stores to kill bacteria, but sometimes they are misused for entertainment in bars or other dark places because ultraviolet light makes some substances fluoresce. Cosmic rays, which are high-energy particles, normally do not penetrate the earth's atmosphere. However, astronauts have reported seeing flashes of light that have been attributed to the effects of cosmic rays either on the eyes or the visual cortex of the brain.

endogenic inputs

Endogenic inputs come from within the body to the brain. When we start exercising, carbon dioxide builds up in the body. This buildup acts as an endogenic signal for the heart and the lungs to work harder. When the level of glucose in the blood drops, we get hungry. Hunger, thirst, pain, fatigue, kinesthesia are all inputs to the brain from the body itself. Some physiological cycles like menstruation may trigger feelings of fatigue, irritability, and depression as the hormone levels change. Exercise has been credited with stimulating the body to generate endorphins that create a feeling of well being. Emotions such as fear release adrenaline into the bloodstream, which triggers many systemic reactions. Several studies have found that what you think can affect your health. Constant worry can create stress that lowers the body's ability to fight diseases, whereas positive thoughts and laughter can actually improve your health.

evaluate solutions

Evaluation of solutions is the analytical aspect of the reasoning process. This is the stage where the relative merits of every solution are calculated. You will need to use your past experience and logic. Some solutions may have some serious drawbacks or may not be ethical or legal. Other solutions may not take into account all the factors and may be incomplete. Incomplete solutions may be evaluated to see if they can be extended to fit the problem. Illegal solutions need to be examined to see if there are legal loopholes or whether the laws can be amended to make the solutions legal. Many successful solutions are sometimes found outside the framework of conventional thinking. The application of the mind without restrictions and the subsequent evaluation and adaptation of the solutions is a powerful method of problem solving. If you can determine some statistical basis for choosing a solution, use it. Many times, the problems that we are trying to solve have been solved by others before us. How is one solution better than another? If we know the results based on our experience, the solution with the better chance of success should be given greater consideration. However, sometimes statistics and our intuition are in conflict. We know that a particular solution worked well in a specific case, but our current problem has some new twists that may make that solution risky. The risk factors should be noted, and a guess should be made about the relative merit of the solution. The evaluation phase is where psychical laws come into play for problems dealing with interpersonal relationships. Suppose that you are trying to get a raise or promotion in your office. You could work hard on your current project and thus have some solid results on which to base your request. You could also try to befriend the boss without working harder on your project. Or, you could just ask the boss for a raise without doing anything else. The approach that you take will depend on how much time you want to invest to get your goal. The personality of your boss and the rules for raises, promotions, seniority, and fairness also play a major role. Many times the best way to get information is to ask the boss directly "What would it take for me to get a raise?" Make sure that you know all the facts before embarking on an approach, and evaluate your approach at regular intervals to make sure that you are still on target.

kinesthetic (motion) sense

Even with the eyes closed, one is aware of the positions of his legs and arms and can perceive the movement of a limb and its direction. The term kinesthesis ("feeling of motion") has been coined for this sensibility.

sweet

Except for some salts of lead or beryllium, sweetness is associated largely with organic compounds (such as alcohols, glycols, sugars, and sugar derivatives). Sensitivity to synthetic sweeteners (e.g., saccharin) is especially remarkable; the taste of saccharin can be detected in a dilution 700 times weaker than that required for cane sugar. The stereochemical (spatial) arrangement of atoms within a molecule may affect its taste; thus, slight changes within a sweet molecule will make it bitter or tasteless (see the figure). Several theorists have proposed that the common feature for all of the sweet stimuli is the presence in the molecule of a proton acceptor, such as the OH (hydroxyl) components of carbohydrates (e.g., sugars) and many other sweet-tasting compounds. It has also been theorized that such molecules will not taste sweet unless they are of appropriate size.

gaseous outputs

Exhaling, sneezing, coughing, burping, and intestinal gases are all outputs of the body that give information about the body. A sigh is a form of exhaling that may indicate weariness or relief. Sneezing and coughing are used to dislodge obstructions in the respiratory passages or as a reaction to irritants. The air expelled during coughing and sneezing may carry bacteria and viruses in droplets of mucus and saliva. Burping and intestinal gases are products of fermentation and digestion that may have offensive smells. The smell of the breath may indicate diet, food residues, the presence of caries, and smoking habits. The smell of a woman's breath changes during menstruation. Many diseases can be identified by the odors emanating from the body. In the days when house calls were common, doctors were advised to blow their nose to increase their olfactory sensitivity before going into the room with the sick patient. Bacterial colonies of Pseudomonas have a grape-like smell, whereas colonies of Proteus have a burned horn smell.

factors affecting taste sensitivity

Fluids of extreme temperature, especially those that are cold, may produce temporary taste insensitivity. People generally seem to taste most acutely when the stimulus is at or slightly below body temperature. When the tongue and mouth are first adapted to the temperature of a taste solution, sugar sensitivity increases with temperature rise, salt and quinine sensitivity decrease, and acid sensitivity is relatively unchanged. Gustatory adaptation (partial or complete disappearance of taste sensitivity) may occur if a solution is held in the mouth for a period of time. The effect of one adapting stimulus on the sensitivity to another one (cross adaptation) is especially common with substances that are chemically similar and that elicit the same taste quality. Adaptation to sodium chloride will reduce one's ability to sense the saltiness of a variety of the inorganic salts but will leave undiminished or even enhance such qualities as bitterness, sweetness, or sourness that were part of the taste of the salt before adaptation. Likewise, adaptation by one acid may reduce sensitivity to the sourness of other acids. Adaptation studies often are complicated by so-called contrast effects; for example, people say that distilled water tastes sweet following their exposure to a weak acid. Water may take on other taste qualities as well; following one's adaptation to a sour-bitter chemical such as urea, water may taste salty. Adaptation tends to diminish or enhance the effect of a subsequent stimulus depending on whether the two stimuli normally elicit the same or a contrasting taste. Thus, the adapted sweetness of water and all normally sweet-tasting substances are enhanced after one has tasted acid (sour). The bitterness of tea and coffee or the sourness of lemon are masked or suppressed by sugar or saccharin. The human gustatory difference threshold (for a just noticeable difference in intensity) is approximately a 20 percent change in concentration. For very weak taste stimuli, however, the threshold sensitivity is less.

nerve function types

Four types of sensory structures are widely distributed in muscles, tendons, and joints: (1) neuromuscular spindles consist of small, fine muscle fibres around which sensory fibre endings are wrapped; (2) Golgi tendon organs consist of sensory nerve fibres that terminate in a branching encapsulated within the tendon; (3) joint receptors (as in the knee) consist of "spray-type" Ruffini endings and Golgi-type and Pacinian corpuscles within the joints; and (4) free nerve endings. All these receptors combine to provide information on active contraction, passive stretch of muscle fibres, and tension. In passive stretch both the muscle-spindle receptors and the tendon receptors send impulses over their sensory (afferent) nerves; in active contraction the spindles exhibit a silent period of neural activity when tension on the parallel fibres is unloaded, while the tendon receptors discharge just as when stretch is passive. The muscle spindle is contractile in response to its own small-diameter, gamma motor (efferent) fibre. The receptors and the gamma fibres of the muscle spindle form a neuromuscular loop that ensures that tension on the spindle is maintained within its efficient operating limits. The excitability of the muscle spindle also can be influenced through other neural pathways that control the general level of excitability of the central nervous system (brain and spinal cord). Activity of the descending reticular formation (a network of cells in the brainstem) may enhance the contraction of the spindle and therefore influence its neural discharges.

afferent nerves

From such afferent nerves, still higher-order neurons make increasingly complex connections with anatomically separate pathways of the brainstem and deeper parts of the brain (e.g., the thalamus) that eventually end in specific receiving areas in the cerebral cortex (the convoluted outer shell of the brain). Different sensory receiving areas are localized in particular regions of the cortex—e.g., occipital lobes in the back of the brain for vision, temporal lobes on the sides for hearing, and parietal lobes toward the top of the brain for tactile function.

Galileo's journal

Galileo's journal entries describe the positions of the moons of Jupiter starting January 7, 1610. The apparatus for making a scientific observation has to be based on well-known scientific principles. The telescope, for instance, is based on magnification of an image using light refraction through lenses. It can be proved that the image perceived through the telescope corresponds to that of the object being observed. In other words, you can trust observations made through telescopes. This is in contrast to magic wands, divining rods, or other devices for which no basis in science can be found. A divining or dowsing rod is a "Y" shaped branch of a tree, which is supposed to be able to help to identify places where there is underground water. The operator holds the divining rod by the top of the "Y", and the single end is supposed to dip when the operator passes over a section of land where there is water. What is the force that makes the divining rod dip? How does the divining rod "sense" the water? A scientist would try to answer these questions by experiments. Place the divining rod on a scale, for example, and then put a bowl of water under the divining rod. Is there a change of weight that indicates force? In another experiment the scale with the divining rod may be placed over a place known to have underground water, and over another place known to be dry. If these experiments show no force being exerted on the divining rod, we have to conclude that divining rods cannot be used as instruments for detecting water. We also have to conclude that any movement of the rod is accomplished by the hands of the person holding it, no matter how much the person denies it.

drugs

Hallucinogens, intoxicants, and other drugs can play havoc with memory and other mental functions. It is amazing to see someone do something outrageous while intoxicated and the next day act as if nothing had happened. Such is human memory! Deprivation of sleep, food, or water can cause hallucinations and altered perceptions. So can illnesses accompanied by high fevers. Moods that we feel such as frustration, anger, fear, are generally mediated by the mind. However, there are reactions that are unexpected even to us. These are the instinctive reactions built into our organism. We may jump at the sight of a spider or snake and stomp our feet. Fear is known to cause lack of control of the bowels and the erection of the hair at the nape of the neck. We vomit at the taste of something awful or at a gory sight. These are instinctive reactions that have allowed our species to survive. We do not have to think about them. We cannot even predict the situations that may trigger them.

waves

How can waves behave like particles and particles behave like waves? Some scientific facts are very hard to comprehend. Yet, these are observable phenomena verified over and over again by many people all over the world. The behavior of the speed of light is another physical fact that is hard to understand. The speed of light in a vacuum is approximately 299,792 kilometers per second. The speed is reduced by about 3% in air and by 25% in water. A famous experiment conducted by Michelson and Morely at the end of the 19th century showed that the speed of light was the same perpendicular to the orbit of the earth and parallel to the orbit of the earth. The orbital speed of the earth of 29 kilometers per second could not be detected in the measurement of the speed of light. Einstein's theory of relativity is based on the constancy of measurement of the speed of light for all observers. A train has its headlight on. The speed of the light emanating from the train is the same whether the train is moving toward you or not! It is hard to accept, but many experiments for over one hundred years have come to the same conclusion.

non-verbal sound inputs

If analyzed carefully, this category could also be grouped under other senses. However, there are some inputs that connect to the fears or desires deep within our brain and establish a special kind of non-verbal communication. The snarl of a dog, a cat rubbing against our legs, a gentle massage, or the wink of an eye are all special kinds of communication. These are more than just simple sounds or visual or tactile inputs. They are meaningful messages for the brain.

Inputs into the body.

If we look at the human body from an engineering point of view, we notice that it has many types of inputs and outputs. The traditional five senses process stimuli from outside the body, or exogenous signals. However, because the body is a very complex structure, there are also endogenous or internal signals that can be perceived by the senses. Many of these stimuli cannot be detected immediately, but only after they have had an effect on the body. Sometimes the effect of these stimuli is on the brain, and if this causes decreased mental function it may prevent us from becoming aware that we are affected.

axons

In addition to the differences in the sensory end structures of the skin, the afferent nerve fibres (axons) from them also show diversity. The nerve fibres range in size from large myelinated (sheathed) axons of 10 to 15 micrometres (millionths of a metre) in diameter to extremely small unmyelinated fibres measuring only tenths of micrometres across. Fatter axons tend to conduct nerve impulses more rapidly than do small fibres; when axons of different diameters form a single bundle (a nerve), they constitute a so-called mixed nerve. Thus, electrical records from a mixed nerve show what are labeled A (fast), B (medium), and C (slow) components that reflect the typical speeds at which axons of different diameters conduct. Although such specialized capsules, such as Pacinian corpuscles, tend to be associated with larger diameter axons, and temperature-sensitive endings tend to be associated with medium-size fibres, a unique relation of each of the skin modalities with one of the A, B, or C fibre groups cannot be supported. All of the cutaneous senses seem to be associated with some fibres of all diameters; furthermore, the C fibres (once thought to be restricted to the pain function) display quite specific sensitivities to nonpainful stimuli applied to the skin. A major neural pathway for tactile impulses runs along the back (in the dorsal columns) of the spinal cord. Afferent fibres enter the cord from the cutaneous nerves and ascend without synaptic break in one (the ipsilateral) dorsal column. This is a very rapidly conducting pathway shared by fibres that mediate sensations of deep pressure and kinesthesis. Other tactual, temperature, and pain information crosses the spinal cord close to the level of entry of the sensory fibres and ascends to the brain in contralateral pathways of the cord (the lateral and ventral spinothalamic tracts).

smell (olfactory) sense

In humans the olfactory receptors are located high in the nasal cavity. The yellow-pigmented olfactory membrane covers about 2.5 square cm (0.4 square inch) on each side of the inner nose. Olfactory receptors are long thin cells ending in 6 to 12 delicate hairs called cilia that project into and through the mucus that normally covers the nasal epithelium, or lining. The end of each receptor narrows to a fine nerve fibre, which, along with many others, travels through a channel in the bony roof of the nasal cavity and enters either of two specialized structures called olfactory bulbs—stemlike projections under the front part of the brain—to end in a series of intricate basketlike clusters called glomeruli. Each glomerulus receives impulses from about 26,000 receptors and sends them on through other cells, eventually to reach higher olfactory centres at the base of the brain. Fibres also cross from one olfactory bulb to the other. Odorous molecules are carried to the olfactory region by slight eddies in the air during quiet breathing, but vigorous sniffing brings a surge of air into the olfactory region. Odour sensitivity may be impaired by blocking the nasal passages mechanically, as when membranes are congested by infection. Pain endings of the trigeminal nerve fibres are widely distributed throughout the nasal cavity, including the olfactory region. Relatively mild odorants, such as orange oil, as well as the more obvious irritants, such as ammonia, stimulate such nerve endings as well as the olfactory receptors.

odour sensitivity

In spite of the relative inaccessibility of the olfactory receptor cells, odour stimuli can be detected at extremely low concentrations. Olfaction is said to be 10,000 times more sensitive than taste. A threshold value for the odorant ethyl mercaptan (found in rotten meat) has been cited in the range of 1/400,000,000th of a milligram per litre of air. A just-noticeable difference in odour intensity may be apparent when there is a 20 percent increase in odorant strength, but at low concentrations as much as a 100 percent increase in concentration may be required. Temperature influences the strength of an odour by affecting the volatility and therefore the emission of odorous particles from the source; humidity also affects odour for the same reasons. Hunting dogs can follow a spoor (odour trail) most easily when high humidity retards evaporation and dissipation of the odour. Perfumes contain chemicals called fixatives, added to retard evaporation of the more volatile constituents. The temporary anosmia (absence of sense of smell) following colds may be complete or partial; in the latter case, only the odours of certain substances are affected. Paranosmia (change in perceived odour quality) also may occur during respiratory infections. Changes in sensitivity are reported to occur in women during the menstrual cycle, particularly in regard to certain odorants (steroids) related to sex hormones. Olfactory sensitivity also is said to become more acute during hunger. Adaptation to odours is so striking that the stench of a junkyard or chemical laboratory ceases to be a nuisance after a few minutes have passed. Olfactory adaptation, as measured by a rise in threshold, is especially pronounced for stronger odours. Cross adaptation (between different odours) may take place; thus, eucalyptus oil may be difficult to detect after one becomes adapted to the smell of camphor. Adaptation was long regarded solely as the result of changes in the olfactory receptor; however, the receptor cells in the nose seem to adapt only partially. Rhythmic discharges continue in the olfactory bulb long after one ceases to detect an odour. Apparently, some olfactory adaptation may occur in the brain as well as in the sense organ.

modern era

In the modern era, the language of communication engineering has been found to be useful in describing human senses. Each sensory modality may be described as a channel that receives stimulus information (input), processes and stores the information (memory), and retrieves it as needed for the effective behaviour (output) of the individual. In addition, devices such as radio, television, radar, and the electron microscope extend the range and power of the senses. In the last analysis, however, all such devices convert (transduce) information back to a form of stimulus energy that is directly perceptible to the unaided senses. For example, a television is a transducer that converts imperceptible electromagnetic waves into visual and auditory signals. For some special purposes, people may employ alternative sensory channels, as when blind people use Braille or other tactile input as substitutes for missing visual channels. While the chemical senses have little function in symbolic communication among people, the use of perfumes in romantic signaling is a notable exception. In general, however, the chemical senses are more directly involved in physiological survival—e.g., warning that a putrid fish is dangerous to eat. Physical well-being also rests heavily on proprioceptors (for sensing bodily position) and on the sense of balance. These structures, monitoring bodily orientation in space, provide crucial sensory feedback for guiding movements (see also movement perception).

insect bites and stings

Insect bites and stings are unpleasant inputs to the human body. Insect stings inject toxins into the body that may elicit allergic reactions accompanied by nausea, pain, and swelling. The bite of the black widow spider is sometimes fatal. Some blood-sucking insects inject saliva at the point of the bite. Insect saliva may cause swelling and itching, but it may also carry bacteria or parasites. Bubonic plague, the so-called "black plague" of the middle ages, which is a bacterial disease, is transmitted by flea bites.

kinesthesia

Kinesthesia is the precise awareness of muscle and joint movement that allows us to coordinate our muscles when we walk, talk, and use our hands. It is the sense of kinesthesia that enables us to touch the tip of our nose with our eyes closed or to know which part of the body we should scratch when we itch.

make full use of your sense

Making use of your senses is the subjective part of the Methodology. This is the stage where your special sensory skills can be put to use. If you have extraordinary hearing, use it. If you have a photographic memory make sure that it gets used for most of your problem solving. Nobody else has your specific impressions of your environment. Your point of view and your observations are unique. Part of using your senses may involve using instrumentation or interaction with others. Lucky charms, divining rods, and other magical devices that do not have reproducible and verifiable functionality do not count as "instrumentation". If you don't have perfect eyesight and you need to see something clearly, use your glasses. Make observations from several points of view to get good depth perception and to confirm impressions. Take photographs if you need to remember something in great detail. Use a tape recorder or a notepad to record your observations for later review. Make sure that your senses are at their best by avoiding intoxicants that affect your perceptions. "Interaction with others" may involve using another being (not necessarily human) to make the observations for you. For example, a blind person may use a seeing-eye dog to get around, a truck driver may use directions from someone else when backing up into a tight spot, a hunter may use a dog's sense of smell for tracking game, or a miner may use a canary to warn him of pockets of unbreathable odorless gases. Whenever you trust someone else's perception more than your own you may find that the conclusions that you reach are unsatisfactory. How many hunters have been led astray by dogs that followed a rabbit's trail rather than the fox's? And how many truck drivers have crashed while backing up because they misinterpreted their helper's signals? Reliance on your own senses is the only way to avoid such problems, but you don't always have this choice. The application of logic may be necessary to determine which perceptions you can trust. Let us say that you are not under the influence of any drugs and you see an apparition of a dead person, what should you do? How do you distinguish hallucinations from real perceptions? How do you know if your senses fool you or if your observations are real? One time-honored test is to pinch yourself to make sure that you are not dreaming. If you should tell someone else about your experience and they don't observe the same things, does this mean that you are crazy or that something is wrong with you? Or does this prove that you have more refined perception that enables you to see things that others do not see? What would it be like to live in a world where only you have color vision and everyone else is colorblind? The difference between real perceptions and hallucinations is that you can repeat and reproduce results from real perceptions but not from hallucinations. In a world where you are the only person with color vision, you would eventually be able to prove to everyone else by objective means that colors, or at least different frequencies of light, do exist.

effects on behaviour

Mammals in the wild state appear to utilize their odour glands for sexual attraction. Rats show a preference for the branch of a maze that has been scented with the odour of a sexually receptive female. It is likely that some rudiments of these effects operate in humans. The most sexually provocative perfumes have a high proportion of musk or a musklike odour. Genuine musk is derived from the sexual glands of the musk deer and is chemically related to human sex hormones; odour sensitivity in humans varies with the menstrual cycle. Among laboratory animals the secretion of reproductive hormones can be markedly influenced by odour stimulation. This seems to be an innate physiological process rather than the result of learning. When the odour of a strange male is presented to a recently mated female, pregnancy block occurs. The normal hormonal changes following copulation are blocked under these conditions, and the fertilized egg fails to survive. A related study of the periodicity and length of the menstrual cycle in women exposed to the normal odours of men suggests that there may be similar effects among humans. Human behaviour, though it is molded and shaped by custom and culture, has many of its roots in basic sensual appetites.

medicines and drugs

Medicines and drugs may be administered orally, by injection, inhalation, etc. The purpose of medicines is to help the organism return to a healthy state. However, sometimes medicines are prescribed to maintain a "normal" state. Antibiotics fall into the first category. Once an infection has been eliminated, the medication can be stopped. Diabetes is in the second category. It is necessary to take insulin all your life in order to live normally. With the large number of drugs available, it is not surprising to find that some of them interact or interfere with each other. Some women on birth control pills have become pregnant while taking some types of antibiotics. Also, grapefruit has been found to elevate levels of some medicines to toxic levels. "Recreational" or illegal drugs such as heroin, cocaine, and LSD are mind-altering drugs that affect the brain adversely, sometimes permanently. Certain non-prescription medicines, such as cough suppressant syrups with dextromethorphan, act on the brain and can dull thinking and creative abilities. "Ritualistic drugs", such as peyote, have hallucinogenic properties and are used in certain religious ceremonies. Alcohol is the most frequently abused mind-dulling drug. It acts as a brain intoxicant that reduces reaction times and impairs the motor functions of the body. Drugs used in psychiatry also modify the way in which the brain works. When used to treat depression or other debilitating mental conditions these drugs actually help to restore the normal functions of the brain, but generally not without side effects.

memes

Memes are ideas or behaviors that can be passed from one person to another by learning or imitation. A culture may be defined as a collection of memes which enable individuals to function within the society. Examples of memes include beliefs, gestures, practices, fashions, habits, songs, and dances. Successful memes propagate themselves and are adopted by the members of a society because they provide a benefit or enable survival. Simple traditions like washing the hands before eating, or the Oriental custom of taking off the shoes before going inside a house promote cleanliness and reduce the rate of infections. People who do not follow these practices will get sick more often or perhaps die from poor sanitation. Thus, the cleanliness meme provides tangible benefits.

memory

Memory is essential to our survival. Memory encodes our perceptions through the various senses. Recall is the ability to remember an event without any aids. Recognition is being able to remember something from the past when perceived again. Recollection involves remembering with the aid of stimuli that serve as clues. Looking at a pressed flower, for example, may bring memories of the events that happened when we put the flower between the pages of a book. Skills acquired through conscious effort, and repeated frequently, eventually become automatic so that it is not necessary to "remember" how to drive a car or where the letters of a keyboard are located. Memory is volatile and can be manipulated. It is not unusual for a person to think that he or she remembers something when authoritative individuals, such as psychiatrists, police detectives, or hypnotists, pressure someone into admitting knowledge about incidents that the person may not have experienced. The person's imagination creates images that persist and can be remembered as if they had actually happened.

nerve function

Microscopic examination of the skin reveals a variety of nerve terminals including free nerve endings (which are most common), Ruffini endings, and encapsulated endings, such Pacinian corpuscles, Meissner's corpuscles, and Krause end bulbs. In laboratory animals some nerve endings seem to respond only to one type of stimulus (e.g., to pressure stimuli of very light weight or to slight temperature changes); others exhibit a broad range of sensitivity. Some receptors show combined sensitivity to both temperature and pressure. In some cases only special types of mechanical stimulation (such as rubbing) may be effective. Furthermore, there is extensive overlap in the areas of skin (receptor fields) for individual nerve fibres, suggesting a neural integration of overlapping afferent inputs of skin nerves. On the other hand, some tactile receptors (e.g., Pacinian corpuscles) respond only to mechanical deformation. A Pacinian corpuscle is an onion-shaped structure of nonneural (connective) tissue built up around the nerve ending that reduces the mechanical sensitivity of the nerve terminal itself. If the onionlike capsule is entirely removed, mechanical sensitivity not only remains but is somewhat greater than when the capsule is present.

reflex

Muscle and tendon receptors combine to play an intimate and crucial role in the regulation of reflex and voluntary movement. Much of this control is automatic (involuntary) and not directly perceptible except in the aftereffects of movement or change of position. The knee jerk, or patellar reflex, that follows a tap just below the kneecap of a freely hanging leg is one such involuntary reflex. Sensory (afferent) impulses from stretching the receptors (e.g., in the muscles) relay to the spinal cord and activate a path to the motor (efferent) nerves leading back to the same muscle. The knee jerk is a purely spinal reflex response (the brain is not required) which is tested usually to determine nerve damage or other interference with the spinal cord motor mechanisms. Besides producing loss of knee jerk, a disease such as syphilis may lead to locomotor ataxia (a clumsy and stumbling gait) when the bacteria (called a spirochete) attacks the sensory nerves of the cord's dorsal column. The result is that the affected individual has difficulty sensing the position of his limbs. Another general function of the muscle receptors is the maintenance of muscle tone (partial contraction) to permit rapid response (fast reaction time) to stimulation. In normal conditions the muscle has tone and is ready to respond; but, when it is without motor stimulation (deafferented), the muscle is flaccid, showing little tone. Upright posture depends on the tone of opposing (extensor and flexor) muscles in response to the effects of gravity.

physiological basis for taste

No simple relationship has been found between the chemical composition of stimuli and the quality of gustatory experience except in the case of acids. The taste qualities of inorganic salts (such as potassium bromide) are complex; epsom salt (magnesium sulfate) is commonly sensed as bitter, while table salt (sodium chloride) is typical of sodium salts, which usually yield the familiar saline taste. Sweet and bitter tastes are elicited by many different classes of chemical compound.

vibration

Nonpainful tactile pattern stimulation is exemplified by vibration. Different frequencies of vibration are readily discriminated, and a tactile communication system employing vibrations on the skin has been devised, particularly for people who cannot see or hear.

scientific method steps

Observation and description of a phenomenon. The observations are made visually or with the aid of scientific equipment. Formulation of a hypothesis to explain the phenomenon in the form of a causal mechanism or a mathematical relation. Test the hypothesis by analyzing the results of observations or by predicting and observing the existence of new phenomena that follow from the hypothesis. If experiments do not confirm the hypothesis, the hypothesis must be rejected or modified (Go back to Step 2). Establish a theory based on repeated verification of the results.

Basic features of sensory structures

One way to classify sensory structures is by the stimuli to which they normally respond This classification is useful because it makes clear that various sense organs can share common features in the way they convert (transduce) stimulus energy into nerve impulses. Thus, auditory cells and vestibular (balance) receptors in the ear and some receptors in the skin all respond similarly to mechanical displacement (distortion). Because many of the same principles apply to other animals, their receptors can be studied as models of the human senses. In addition, many animals are endowed with specialized receptors that permit them to detect stimuli that humans cannot sense. The pit viper, for instance, boasts a receptor of exquisite sensitivity to "invisible" infrared light. Some insects have receptors for ultraviolet light and for pheromones (chemical sex attractants and aphrodisiacs unique to their own species), thereby also exceeding human sensory capabilities.

food choice

One's ability to taste is intimately involved with his eating habits or with his rejection of noxious substances. One of the earliest reflex responses of the infant, that of sucking, can be controlled by gustatory stimuli. Sweet solutions are sucked more readily than plain water; bitter, salty, or sour stimuli tend to stop the sucking reflex. Many animals provide clear examples of beneficially selective feeding behaviour. Laboratory rats, when given an unhampered choice of carbohydrates, proteins, vitamins, and minerals (each in a separate container), show consistent patterns of selection that may be modified by physiological stresses and strains. A rat made salt-deficient by removal of its adrenal glands, for example, will increase its intake of sodium chloride sufficiently to maintain health and growth; normally, such gland removal is fatal in the absence of salt-replacement therapy. Histories of similar effects have been reported in humans, one case being that of a child with an adrenal disorder who kept himself alive by satisfying an intense salt craving.

gravity

Our sense of equilibrium in the gravitational field of the earth is provided by the semicircular canals in the ear. These canals are lined with filaments that are stimulated by calcium carbonate crystals suspended in a fluid. The rotation of the moon around the earth every 27 1/3 days creates tidal forces that affect many living organisms, but is not known to have a significant effect on humans. Some fish are known to spawn in the beach at high tide when the moon is full. The human menstruation cycle of approximately 28 days may be a legacy of our ancestral origins in the sea.

chemical elements that are odourous

Only seven of the chemical elements are odorous: fluorine, chlorine, bromine, iodine, oxygen (as ozone), phosphorus, and arsenic. Most odorous substances are organic (carbon-containing) compounds in which both the arrangement of atoms within the molecule as well as the particular chemical groups that comprise the molecule influence odour. Stereoisomers (i.e., different spatial arrangements of the same molecular components) may have different odours. On the other hand, a series of different molecules that derive from benzene all have a similar odour. It is of historic interest that the first benzene derivatives studied by chemists were found in pleasant-smelling substances from plants (such as oil of wintergreen or oil of anise), and so the entire class of compounds was labelled aromatic. Subsequently, other so-called aromatic compounds were identified that have less-attractive odours.

Oral and Written Communication

Oral and written communication have a huge effect on the mind. Earlier chapters discussed language as inputs and outputs from the body. The power of words cannot be underestimated. Words have the power to move nations into revolution. Words can be used to heal. Words can be used to hypnotize. Words can be used to pass messages to future generations. Voices from the past affect our daily lives today. More than 2300 years ago, Euclid developed exercises in geometry that are still used today, and Aristotle wrote about the five senses of the human body. Although we focus on "words" as a means of communication, we have to recognize that there are different kinds of languages. We could say that smells comprise a language. Bad smells mean "don't eat me", good smells mean "good to eat". There are specialized languages for mathematics. The inputs and outputs of an electronic calculator comprise a mathematical language. Although the mind is capable of working with many different language representations, visual and oral forms are the most common.

sounds

Our bodies respond to sounds in fairly mechanical ways. Sudden noises can cause a person to jump away from the noise, or turn the head in the direction of the noise. Soothing, rhythmic noises such as the sound of the sea, a gurgling brook, or the beating heart in a mother's breast are well known for their calming effects. Buzzing sounds close to the ears cause us to wave the hands by our ears as if to repel insects. Certain high-pitched noises such as scratching fingernails on a blackboard or the noise of a pencil on paper can "make your skin crawl", which is an erection of the hairs on the skin. Loud repeated noises can reduce the sensitivity of the ears and eventually cause hardness of hearing or even deafness. Boilermakers that used noisy riveting equipment were particularly prone to deafness as an occupational hazard. In the era of high-fidelity sound equipment with powerful amplifiers, many young people are losing their hearing by listening to music at very loud levels.

parasites

Parasites come into the body through many mechanisms. Inhale the dust of a soiled bed linen, and you may get pinworms. Take a dip in a lake or river and get schistosomiasis. Get bitten by a mosquito and get malaria or sleeping sickness. Hug your mother and get follicle mites. Eat uncooked pork and get trichinosis. Eat food contaminated with fecal matter and you may get roundworms. Roundworms generally inhabit the intestine, but because of their complex life cycle, sometimes they end up in other parts of the body, including the brain

Personality Analysis Exercises.

Probably the best way to get to know other people is to know yourself, not as you imagine yourself to be, but as other people see you. Your character attributes can best be judged by your actions. You may think that you are generous, but others may view you as stingy. You may think that you are easy to get along with, but others may think that you are domineering and pushy. The Zamora Personality Test enables you to know yourself in a more objective way You should study the results of the test and try to determine why the results came out the way they did for each category. You may want to take the test multiple times, changing you answers to determine what the results would be if you acted differently or had different attitudes. The test may also be used as a guide to evaluate other people by answering the questions based on their actions. Once you know the character attributes of a person, you may be able to predict better their actions or reactions. It is also possible to do a Personality Compatibility Analysis. Carl Jung, a contemporary of Freud developed a theory of psychological types stating that each person had two fundamental attitude types: introversion and extroversion. Extroverts can be described as outgoing, easily adaptable, and confident about unknown situations. Introverts are hesitant, reflective, somewhat mistrustful, and not socially outgoing. Jung also thought that people further differed from one another depending on the degree to which they developed the conscious use of four functions: thinking, feeling, sensation, and intuition. Thinking enables us to recognize meaning, feeling helps us to evaluate, sensation provides us with perception, and intuition points to possibilities available to us. Jung considered feeling and thinking to be "rational" functions, whereas sensation and intuition were considered "non-rational" in that they give rise to knowledge that cannot be reduced to any other mode of understanding. Jung observed that people tend to develop one rational and one non-rational function in addition to the introverted or extroverted attitude. The Extrovert/Introvert, Intuitive/Sensing, Feeling/Thinking model is able to describe eight personality types. Katharine Briggs and Isabel Briggs Myers extended Jung's types by adding a Judging/Perceiving aspect to the personality classifications thus doubling the number of categories to sixteen. The Myer The Jungian personality type is useful in a broad sense, but it cannot be used for essential everyday situations. The Extrovert/Introvert part of the psychological personality type provides information about social interaction. The Intuitive/Sensing, Feeling/Thinking, Judging/Perceiving provides information of how information from the senses is processed. Would you marry an extrovert/sensing/feeling/perceiving individual? Probably not before knowing a lot more about the person. A more comprehensive test is the 16PF (Personality Factors) developed by psychologist Raymond B. Cattell who defined personality as "that which permits a prediction of what a person will do in a given situation". These psychological tests still do not answer some of the questions that are essential for a successful relationship, such as whether a person is responsible, honest, and mature. For this reason we have developed the Zamora Personality Test. The Zamora Personality Test is divided into two parts: Test of Individual Attributes and Test of Interpersonal and Social Attributes. A person in a deserted island can display individual attributes, such as alertness, contentment, and anger. Interpersonal and social attributes are those that manifest themselves in the company of other people. Envy, rudeness, or loyalty, for example, cannot be expressed unless there are two or more people. No system of classification can ever be complete or universal, and the attributes determined by this test are not necessarily independent of each other. A goal-oriented person, for instance, may also need to be resourceful and systematic to be successful although this test may consider these as different aspects of the psychical categories or personality attributes.

R. Murray

Real science hops from failure to failure, from several falsifiable hypotheses in confused competition to the next set, until a consensus evolves around a surviving paradigm that often uses aspects of its predecessors, adding unexpected novel ideas that lead to productive questions and more definitive tests, as disparate data starts to fit an overall unifying view. — R. Murray

limitations of the scientific method

Science has some well-known limitations. Science works by studying problems in isolation. This is very effective at getting good, approximate solutions. Problems outside these artificial boundaries are generally not addressed. The consistent, formal systems of symbols and mathematics used in science cannot prove all statements, and furthermore, they cannot prove all TRUE statements. Kurt Gödel showed this in 1931. The limitations of formal logical systems make it necessary for scientists to discard their old systems of thought and introduce new ones occasionally. Newton's gravitational model works fairly well for everyday physical descriptions, but it is not able to account for many important observations. For this reason, it has been replaced by Einstein's general theory of relativity for most celestial phenomena. Instead of talking about gravity, we now are supposed to talk about the curvature of the four-dimensional time-space continuum. Scientific observations are also subject to physical limits that may prevent us from finding the ultimate truth. The Heisenberg Uncertainty Principle states that it is impossible to determine simultaneously the position and momentum of an elementary particle. So, if we know the location of a particle we cannot determine its velocity, and if we know its velocity we cannot determine its location. Jacob Bronowski wrote that nature is not a gigantic formalizable system because to formalize it we would have to make some assumptions that cut some of its parts from consideration, and having done that, we cannot have a system that embraces the whole of nature. The application of the scientific method is limited to independently observable, measurable events that can be reproduced. The scientific method is also applicable to random events that have statistical distributions. In atomic chemistry, for example, it is impossible to predict when one specific atom will decay and emit radiation, but it is possible to devise theories and formulas to predict when half of the atoms of a large sample will decay. Irreproducible results cannot be studied by the scientific method. There was one day when many car owners reported that the alarm systems of their cars were set off at about the same time without any apparent cause. Automotive engineers were not able to discover the reason because the problem could not be reproduced. They hypothesized that it could have been radio interference from a passing airplane, but they could not prove it one way or another. Mental conceptual experiences cannot be studied by the scientific method either. At this time there is no instrumentation that enables someone to monitor what anybody else conceives in their mind, although it is possible to determine which part of the brain is active during any given task. It is not possible to define experiments to determine objectively which works of art are "great", or whether Picasso was better than Matisse. So-called miracles are also beyond the scientific method. A person has tumors and faces certain death, and then, the tumors start shrinking and the person becomes healthy. What brought about the remission? A change in diet? A change in mental attitude? It is impossible to go back in time to monitor all variables that could have caused the cure, and it would be unethical to plant new tumors into the person to try to reproduce the results for a more careful study.

target your goals

Solving the right problem is the most important aspect of problem solving. Frequently, we make assumptions that lead us away from the correct solution. For example, an elementary school problem describes people getting in and out of an elevator. First, two men and one woman go into an empty elevator. At the next stop, one man gets out and three women go in. At the next floor, two men get in, and a woman and a man go out. We cannot solve a problem until we know what the problem is. This problem intentionally mentions men and women to direct your attention to the occupants of the elevator and then surprises you with a question that you might not have expected. How many stops did the elevator make? In our eagerness to show how smart we are, we typically start focusing on the details and do not wait to find out what the real problem is. It is also important to determine if the problem has a solution. Has somebody else solved this problem before? If so, how? If not, do you have a workable plan for solving it? Do you have the qualifications, experience, and education required to solve it? Are you willing to work toward fulfillment of the solution? No one can solve problems that have no solution and no one can solve any problems without spending some effort. If your goal is to make a million dollars in the stock market, you have to have some starting capital, you have to know how the stock market works, you have to study carefully the companies in which you want to invest, you have to have contingency plans for how to cope and overcome losses, etc. If you are a detective and want to solve a criminal case, you have to get all the facts by talking with witnesses, you have to study the physical evidence, you have to set up a convincing case for a conviction in court, etc. If you have a choice of two jobs, you have to look at the prospects for advancement, you have to consider your duties, with whom you will be working, and who will be your boss. Even if you have a clear picture of what you want to accomplish, there are no guarantees that you will succeed. Your plans for a million dollars may crumble due to volatile markets, your criminal may have committed a perfect crime, or you end up working for the boss from hell. One thing is certain, however. If you do not have clearly defined goals, you cannot focus your efforts toward a solution

synesthesia

Some people experience a phenomenon called synesthesia in which one type of stimulation evokes the sensation of another. For example, the hearing of a sound may result in the sensation of the visualization of a color, or a shape may be sensed as a smell. Synesthesia is hereditary and it is estimated that it occurs in 1 out of 1000 individuals with variations of type and intensity. The most common forms of synesthesia link numbers or letters with colors.

subliminal perception

Subliminal perception and communication is one of the most interesting phenomena for anyone wanting to increase their psychic potential. The word "subliminal" means beyond the range of conscious perception. In other words, if a note is played beyond your range of hearing, or a visual image is flashed too fast, you will not be able to perceive it. However, experiments have shown that such subliminal messages do influence the decisions that we make. Subliminal messages may also be encoded, not by having stimuli beyond the limits of our perception, but by imbedding them in an unexpected context. Advertisers have used slim women and tough cowboys for promoting tobacco products. "You too can be like this" or "This is sexy" is the message. Subliminal messages do work. Nobody is immune to them. The transition from subliminal to conscious may never happen, but sometimes we get premonitions. We get the feeling that something is going to happen, but we do not know and cannot explain why we think so. This may be the assimilation of various subliminal perceptions that are trying to reach the conscious level.

Thus far, we have listed as requirements for the Methodology a) independent thinking, b) reliance on your own perceptions, and c) a practical approach toward solving problems. The Methodology itself consists of five basic steps that could be applied to any type of problem solving.

Target your goals Make full use of your senses Apply your mind Evaluate solutions Draw conclusions

zamora personality test

The Zamora Personality Test program takes into consideration that some attributes are mutually exclusive. In general, you cannot be happy and sad at the same time; you cannot be alert and inattentive simultaneously. The set of over 150 statements for each part of the test is weighted toward identifying the predominant characteristics of an individual after removing inconsistencies. Below is an exercise to evaluate six advertisements from the "personals" section of a newspaper. Three are from women and three from men. We can evaluate them in terms of the classifications established above to try to understand what each person is like, what they desire in a partner, and what vital information is missing from the ad. We also can make some predictions about the chance for success for the person placing the ad. You will notice that marital status, race, and philosophical beliefs are often primary criteria in the ads. In the following analyses, we place the categories of the attributes by each of the terms. For example, the term (s8) by the word "attractive" indicates that this is considered a social attribute of the physical appearance category as indicated above. Terms starting with an i refer to individual attribute categories. More details about the categories are provided in the Personality Compatibility Analysis page. The following abbreviations are used in the ads: D=Divorced, W=White, B=Black, F=Female, M=Male, P=Professional, C=Christian, S=Single. CUTE AND SWEET. Attractive WF, 41, 5'4", 110 lbs, enjoys movies, dining out, music, and just relaxing. Seeking attractive, secure WM, 41-46, who's sincere, honest, and enjoys sharing fun times. CUTE AND SWEET tells us that she considers herself cute and attractive (s8). Sweet probably means affectionate (s5). She enjoys passive activities like movies, music, and relaxing (i3). She wants an attractive (s8), secure (i2), sincere (s3), and honest (s9) man. CUTE AND SWEET only tells us about her physical appearance and her preference for passive activities. She does not mention whether she is sincere and honest, but we can give her the benefit of the doubt and assume that because she requires these attributes in a man, she also possesses them. Since she is passive, she may be better off with a man who is initiative (i1), but this may require too much effort from her for a stable relationship. The sincerity and honesty that she is looking for may turn out to be a double-edged sword. On the one hand, it is good to have a relationship where you can trust that you are not being deceived, but sincerity and honesty have to be tempered with compassion (s4) and diplomacy (s2). She may find an attractive, secure, sincere, and honest man who tells her "Yes, you are cute and attractive, but my first girlfriend was prettier". That kind of honesty can be damaging to a relationship. SEEKING SOULMATE. SBPF, 34, 5'5", long hair, brown eyes, single parent, enjoys jazz, gospel, Italian food, bowling, movies, videos in front of fireplace. Seeking loving, considerate, honest SBPM, 32-40. SEEKING SOULMATE tells us that she likes both active and passive activities (i3) like bowling, music and movies. We don't know anything else about her except by assuming that she also has the characteristics that she is seeking in a man, especially since she would like to find a soulmate. The man must be loving (s5), considerate (s6), and honest (s9). SEEKING SOULMATE will have a hard time finding a real soulmate for one main reason - there is at least one child involved. Any relationship will always have to deal with the tension of the visitation rights and support payments of the biological father. Given the age of SEEKING SOULMATE, the child could be almost a teen-ager, which could also place stress on the relationship between the mother and the man that she is seeking. Many children have loyalty toward their biological parents and resent the intrusion of "strangers" into their home environment. The man will also need to be generous (s4), forgiving (s4), and patient (i2) to have a successful relationship in this situation. FULL OF FUN. SWCF, 39, loves books, animals, gardening, conversation, travel, outdoors. Seeking guy who knows how to hug and think positively. I've been told my eyes and smile can melt hearts. Interested? FULL OF FUN defines herself as Christian which means that religion and a religious way of life are important to her. FULL OF FUN likes intellectual activities such as reading (i4), active pastimes like gardening and outdoors (i3), conversation (s5), and travel (i9). She wants a man who can show affection by hugging (s5) and who is optimistic (i7). Obviously, FULL OF FUN also would like a man who respects (s6) her religious principles and is energetic (i3) to keep up with her. The man should also be able to give compliments and not be jealous (s6) of the man who told her that her eyes and smile could melt hearts. Of the three ads from women that we have analyzed, this one provides the most information about herself. TREAT YOU RIGHT. Honest, reliable man, 34, lean, athletic build, financially/emotionally secure, seeks sensitive, caring, fun-loving female, 24-35, with interests in outdoors, sports and dancing. Race unimportant. TREAT YOU RIGHT claims to be honest (s9), reliable (s3), financially (i5) and emotionally (i2) secure. He likes athletic activities (i8). He seeks a sensitive (s4) and caring (s4), fun-loving (i2) woman who also has athletic (i8) inclinations. The fact that race is unimportant means that he is not prejudiced (s6) and that has no concern for any social stigma from mixed race relations. As in the previous examples, we can use the categories of individual and social attributes to look for gaps to try to determine what we don't know about an individual. Because TREAT YOU RIGHT seems to have everything under control we have to wonder just a little bit about his level of aggressiveness (s1) and the ways in which he deals with people (s2). He might not be the right kind of guy for an assertive, independent woman, although he sounds like a fine man in many ways. EASYGOING, HONEST. Straightforward, DWM, 56, lives in the country, enjoys country-living, games, movies, reading, grits, black-eyed peas, and all other gourmet dishes! Seeking companionship with special, sweet S/DWF, 25-60, with similar interests. EASYGOING's way of life revolves about southern country living. We don't know whether he is into farming or ranching. He tells us that he is easygoing (s5), honest (s9), and straightforward (s3). He likes passive and active activities (i3), and has a taste for southern food. EASYGOING has a sense of humor (i2) as shown by his calling grits a "gourmet" dish. He does not want much in a woman except for her to be sweet (s5). The fact that he is 56 and is seeking a relationship with a woman as young as 25 makes you wonder whether he is trying to make up for lost opportunities during his marriage(s). I'M LOST AND LONELY. I'm a lonely man, young, shy and bashful. Looking for a friend or that person to help me. Do you like talking, reading, movies, cuddling and long romantic dinners? LOST AND LONELY may be lonely (s10) because he is shy and bashful (s5) and because he is young (i8) and inexperienced (i6). He is looking for help, which means that he probably will be submissive (s2) in a relationship if he described himself correctly. Since he can read by himself, his real interests seem to be talking and cuddling (s5). LOST AND LONELY sounds like a person who is really after the cuddling, but makes himself appear helpless (s7) to get some sympathy. Conspicuously absent are any references to his truthfulness and honesty (s9), his dependability (s3), or his goals in life. He also does not say what kind of help he needs, although it seems all too obvious that this topic will come out during the cuddling.

apply your mind

The application of your mind is the creative aspect of problem solving. In this step you want to grasp the whole problem and look at it from different perspectives without selecting a solution. This is an unstructured process of contemplating and writing down all ideas regardless of how sensible they are. You can stretch your imagination to the limit and use brainstorming techniques. Assimilate facts, enumerate impressions, explore your feelings. If some solution gives you a bad feeling, write down what that feeling is for further evaluation later. Use your dreams to get insights into the problem. You may even be able to experience "lucid dreaming" where you are in control of your dreams and can take them in any direction you wish. Make sure to write down any ideas that come in your sleep. Bertrand Russel, the mathematician and philosopher, reported that he was able to solve during his sleep mathematical problems that had been troubling him the evening before. Try meditation. Focus on the problem that you want to solve. Record any solutions that may occur to you while you are in a relaxed state. Try looking at the problem from someone else's perspective. How would they feel and why? How would you react in their place? How would they approach the problem? Putting yourself in someone else's shoes is not easy to do. You need to take their motivations, needs, and personalities into consideration, but if you manage to do it, you can sometimes get insightful solutions.

logical problems

The capability for solving complex logical problems may be what differentiates humans, more than anything else, from other living beings. Logic is what makes us understand that things are not what they seem. Our ability to visualize hypothetical situations makes it possible to develop solutions to problems. Once we have visualized a solution, our analytical skills can lead us toward practical solutions. We may not be able to see in the ultraviolet range, but we may design instruments to do so. We may not be able to see atoms, but we can design experiments that enable us to know their properties. Each stage of scientific advancement has usually been made by trying to reach a logical conclusion consistent with our observations. We no longer believe in demons as the cause of disease. We now believe in viruses, bacteria, genetic defects, and environmental pollution as the real causes of disease. Our irrational and unfounded "superstitions" have given way to "knowledge"

Syringomyelia

The dissociation of cutaneous senses is demonstrated in the course of some diseases; for example, in syringomyelia, degeneration of the central canal of the spinal cord leads to loss of pain and temperature sensitivity. Nevertheless, the patient still can experience pressure. In some instances there may be a complete absence of pain sensitivity with disastrous consequences such as bruises, cuts, or even the loss of body parts. Still other instances of dissociation of pain versus pressure occur in surgical procedures (such as tractotomy) in which spinal tracts or parts of the nerves leading into the brainstem are selectively cut. Such operations are designed specifically to relieve pain without unduly diminishing pressure sensitivity.

hearing

The ear is the organ of hearing. The outer ear protrudes away from the head and is shaped like a cup to direct sounds toward the tympanic membrane, which transmits vibrations to the inner ear through a series of small bones in the middle ear called the malleus, incus and stapes. The inner ear, or cochlea, is a spiral-shaped chamber covered internally by nerve fibers that react to the vibrations and transmit impulses to the brain via the auditory nerve. The brain combines the input of our two ears to determine the direction and distance of sounds. The inner ear has a vestibular system formed by three semicircular canals that are approximately at right angles to each other and which are responsible for the sense of balance and spatial orientation. The inner ear has chambers filled with a viscous fluid and small particles (otoliths) containing calcium carbonate. The movement of these particles over small hair cells in the inner ear sends signals to the brain that are interpreted as motion and acceleration. The human ear can perceive frequencies from 16 cycles per second, which is a very deep bass, to 28,000 cycles per second, which is a very high pitch. Bats and dolphins can detect frequencies higher than 100,000 cycles per second. The human ear can detect pitch changes as small as 3 hundredths of one percent of the original frequency in some frequency ranges. Some people have "perfect pitch", which is the ability to map a tone precisely on the musical scale without reference to an external standard. It is estimated that less than one in ten thousand people have perfect pitch, but speakers of tonal languages like Vietnamese and Mandarin show remarkably precise absolute pitch in reading out lists of words because pitch is an essential feature in conveying the meaning of words in tone languages. The Eguchi Method teaches perfect pitch to children starting before they are 4 years old. After age 7, the ability to recognize notes does not improve much.

electrical activity

The electrical signals in the brain are in the order of 100 microvolts, that is about fifteen thousand times smaller than an ordinary flashlight battery. These signals have wave frequencies of between 1 and about 20 Hertz (or cycles per second). The electrical signals in the heart are around 1 millivolt, ten times stronger than those of the brain, but still very small and impossible to detect outside the human body except through great amplification. By contrast, electric eels have special nerve endings that enable them to generate from 200 to 600 volts, enough to electrocute a person. The neurons of the human brain have been estimated to generate about 25 watts of power.

muscle receptors

The exact contribution of the muscle receptors to sensation is not entirely understood. It seems clear, however, that they are not essential to the sensation of bodily position. The appreciation of passive movement of the limbs probably comes largely from the joints, since, after anesthetizing the overlying skin and muscles, sensibility to the limb movement seems little affected. Very few of the impulses arising from the muscle receptors themselves reach the cerebral cortex; instead, they ascend in the spinal pathways to another part of the brain, the cerebellum, where they interact in the automatic control of bodily movement. Impulses arising from the joint receptors, on the other hand, have been recorded in both the thalamus and cerebral cortex, the degree of angular displacement of a joint being reflected systematically in these structures by the frequency of nerve impulses. Symptoms of some diseases also emphasize the importance of joint sensitivity. When bone disease, for example, destroys only the joint receptors, the ability to appreciate posture and movement is lost

bitter

The experience of a bitter taste is elicited by many classes of chemical compounds and often is associated with sweet and other gustatory qualities. Among bitter substances are such alkaloids (often toxic) as quinine, caffeine, and strychnine. Most of these substances have extremely low taste thresholds and are detectable in very weak concentrations. The size of such molecules is theoretically held to account for whether or not they will taste bitter. An increase in molecular weight of inorganic salts or an increase in length of chains of carbon atoms in organic molecules tends to be associated with increased bitterness. A substantial minority of people exhibit specific taste blindness, an inability to detect as bitter such chemicals as phenylthiocarbamide (PTC). Taste blindness for PTC and other carbamides appears to be hereditary (as a recessive trait), occurring in about a third of Europeans and in roughly 40 percent of the people in Western India. Taste blindness for carbamides is not correlated with insensitivity to other bitter stimuli.

sight

The eye is the organ of vision. It has a complex structure consisting of a transparent lens that focuses light on the retina. The retina is covered with two basic types of light-sensitive cells-rods and cones. The cone cells are sensitive to color and are located in the part of the retina called the fovea, where the light is focused by the lens. The rod cells are not sensitive to color, but have greater sensitivity to light than the cone cells. These cells are located around the fovea and are responsible for peripheral vision and night vision. The eye is connected to the brain through the optic nerve. The point of this connection is called the "blind spot" because it is insensitive to light. Experiments have shown that the back of the brain maps the visual input from the eyes. The brain combines the input of our two eyes into a single three-dimensional image. In addition, even though the image on the retina is upside-down because of the focusing action of the lens, the brain compensates and provides the right-side-up perception. Experiments have been done with subjects fitted with prisms that invert the images. The subjects go through an initial period of great confusion, but subsequently they perceive the images as right side up. The range of perception of the eye is phenomenal. In the dark, a substance produced by the rod cells increases the sensitivity of the eye so that it is possible to detect very dim light. In strong light, the iris contracts reducing the size of the aperture that admits light into the eye and a protective obscure substance reduces the exposure of the light-sensitive cells. The spectrum of light to which the eye is sensitive varies from the red to the violet. Lower electromagnetic frequencies in the infrared are sensed as heat, but cannot be seen. Higher frequencies in the ultraviolet and beyond cannot be seen either, but can be sensed as tingling of the skin or eyes depending on the frequency. The human eye is not sensitive to the polarization of light, i.e., light that oscillates on a specific plane. Bees, on the other hand, are sensitive to polarized light, and have a visual range that extends into the ultraviolet. Some kinds of snakes have special infrared sensors that enable them to hunt in absolute darkness using only the heat emitted by their prey. Birds have a higher density of light-sensing cells than humans do in their retinas, and therefore, higher visual acuity.

feedback system

The feedback system leading to muscle tone is a delicately balanced mechanism. The gamma loop feeds back information that maintains muscle tone and postural adjustments appropriate to the efficient performance of different voluntary actions. The afferent input from the muscle spindles via the spinal cord to the cerebellum traverses an extensive circuit involving interactions of excitatory and inhibitory processes, the end result of which ensures smooth and finely coordinated movements. Disease or other neurological damage in the cerebellum is characterized by distortions of movement and posture. Some sufferers of cerebellar disorders display crude, overactive motor activity (ballistic movement). Other individuals with cerebellar disease display what resembles a drunken gait, jerkily stumbling and swaying along. By relying on other sensory cues (e.g., visual and tactile), some people are able to compensate for awkward and uncoordinated movements associated with cerebellar damage.

draw a conclusion

The final stage of the Methodology is choosing a solution. This is the deductive portion of the reasoning process. We have listed possible solutions, we have evaluated them and ranked them, and now we make the final choice. For some problems we have the opportunity to go back and try other solutions. For other problems our choice of solutions is irrevocable. Once we have made a choice, the circumstances change and we can never go back to the initial state. If we made a wrong choice, we will regret it, and we will have a new and different problem to solve. Time also becomes a factor in selecting a solution. Our lifetimes are finite. If we want to accomplish something, the solution should not require more time than our expected life span. Lack of action, sometimes unwittingly, becomes another choice. You cannot think too long about which pedal to push to keep your car from falling in a ditch or to avoid a collision. Good luck is said to consist of preparation and opportunity. If we know which options we have, we are more likely to know what to do when the opportunity comes.

sour

The hydrogen ions of acids (e.g., hydrochloric acid) are largely responsible for the sour taste; however, although a stimulus grows more sour as its hydrogen ion (H+) concentration increases, this factor alone does not determine sourness. Weak organic acids (e.g., the acetic acid in vinegar) taste more sour than would be predicted from their hydrogen ion concentration alone; apparently the rest of the acid molecule affects the efficiency with which hydrogen ions stimulate.

vestibular sense (equilibrium)

The inner ear contains parts (the nonauditory labyrinth or vestibular organ) that are sensitive to acceleration in space, rotation, and orientation in the gravitational field. Rotation is signaled by way of the semicircular canals, three bony tubes in each ear that lie embedded in the skull roughly at right angles to each other. These canals are filled with fluid called endolymph; in the ampulla of each canal are fine hairs equipped with mechanosensing stereocilia and a kinocilium that project into the cupula, a gelatinous component of the ampulla. When rotation begins, the cupula is displaced as the endolymph lags behind, causing the stereocilia to bend toward the kinocilium and thereby transmit signals to the brain. When rotation is maintained at a steady velocity, the fluid catches up, and stimulation of the hair cells no longer occurs until rotation suddenly stops, again circulating the endolymph. Whenever the hair cells are thus stimulated, one normally experiences a sensation of rotation in space. During rotation one exhibits reflex nystagmus (back-and-forth movement) of the eyes. Slow displacement of the eye occurs against the direction of rotation and serves to maintain the gaze at a fixed point in space; this is followed by a quick return to the initial eye position in the direction of the rotation. Stimulation of the hair cells in the absence of actual rotation tends to produce an apparent "swimming" of the visual field, often associated with dizziness and nausea. Two sacs or enlargements of the vestibule (the saccule and utricle) react to steady (static) pressures (e.g., those of gravitational forces). Hair cells within these structures, similar to those of the semicircular canal, possess stereocilia and a kinocilium. They also are covered by a gelatinous cap in which are embedded small granular particles of calcium carbonate, called otoliths, that weigh against the hairs. Unusual stimulation of the vestibular receptors and semicircular canals can cause sensory distortions in visual and motor activity. The resulting discord between visual and motor responses and the external space (as aboard a ship in rough waters) often leads to nausea and disorientation (e.g., seasickness). In space flight abnormal gravitational and acceleratory forces may contribute to nausea or disequilibrium. In some diseases (e.g., ear infections), irritation of vestibular nerve endings may cause the affected individual to be subject to falling as well as to spells of disorientation and vertigo. Similar symptoms may be induced by flushing hot and cold water into the outer opening of the ear, since the temperature changes produce currents in the endolymph of the semicircular canals. This effect is used in clinical tests for vestibular functions and in physiological experiments. Externally applied electrical currents may also stimulate the nerve endings of the vestibule. When a current is applied to the right mastoid bone (just behind the ear), nystagmus to the right tends to occur with a reflex right movement of the head; movement tends to the left for the opposite mastoid. Destruction of the labyrinth in only one ear causes vertigo and other vestibular symptoms, such as nystagmus, inaccurate pointing, and tendency to fall.

Summary of material inputs and outputs.

The material inputs into the body are food, drink and air. The chemical components of food and drink are proteins, fats, carbohydrates and water. The material outputs of the body are feces, urine, sweat and carbon dioxide. Feces consists of undigested food. The kidneys are responsible for excreting urine which is mostly water and two nitrogen-containing substances: uric acid produced from nucleic acid metabolism, and urea produced from protein metabolism. Sweat is mostly water with some electrolytes (mostly sodium chloride). Respiration is responsible for burning carbohydrates, fats, and proteins to produce carbon dioxide. Body weight is lost by the output of carbon dioxide through the lungs, one breath at a time. Exercise increases the output of carbon dioxide and accelerates weight loss.

mind

The mind is not a physical entity, therefore it cannot be defined scientifically. The mind is generally considered to be the awareness of consciousness and the manifestations of thought, perception, emotion, determination, memory, and imagination that takes place within the brain. The human brain has three principal structures. The cerebrum, which is the biggest structure, is the center for intelligence and reasoning. The cerebellum, at the back of the skull, is involved in keeping balance and posture. The medulla, which is a stem leading to the spinal column, handles involuntary functions such as respiration. The functionality of the brain is hard to study because it is a complex dynamic system. It is theorized that memories in the brain are stored as chemical structures and as a neural network, with the information represented as a specific set of synaptic connections. The operation of the brain depends not only on the electrical signals passed by the neurons, but also on the influence of various neurotransmitting substances whose presence or absence can cause sleepiness, depression or even schizophrenia. Experiments have shown that rats kept in a complex, challenging environment develop more neural connections in the cerebral cortex than those kept in dull and uninteresting environments. Experiments have also shown that untrained fish that are fed the brains of fish trained to avoid the dark, also avoid the dark. It is possible that there are many learning mechanisms, each adapted to the brain structure of the learner. he cerebrum consists of two cerebral hemispheres connected by the corpus callosum, which makes it possible for our left side to know what the right side is doing. This is necessary because most of the sensory organs and motor control on the left side of the body are connected to the right hemisphere, and vice-versa. The only exception seems to be the sense of smell where the right and left nostril sensors are connected to the right and left hemispheres, respectively. The cerebrum has four distinct sections called the frontal, parietal, temporal, and occipital lobes. The frontal lobe plays a part in planning, judgment, language, memory, motor function, problem solving, sexual behaviour, socialization and spontaneity. The parietal lobe integrates sensory information and helps in the manipulation of objects. The temporal lobe is involved in spatial perception and auditory processing. The occipital lobe is the visual processing center. The cells in this lobe are arranged as a spatial map of the retinal field. Extensive psychological and physiological studies of normal people using imaging technologies and studies of people who have had injuries or suffered strokes in portions of their brain have shown that verbal ability (writing, speaking) and logical ability (arithmetic) are dominant in the left side of the brain, even for left-handed people. Whereas the right side of the brain is responsible for three-dimensional vision, pattern recognition (including recognition of faces), musical ability and holistic reasoning. Thus, there is the popular notion that a "rational" person is a "left-brain" person, whereas an "intuitive" person relies mostly on the right part of the brain.

The Scientific Method.

The scientific method is a process for creating models of the natural world that can be verified experimentally. The scientific method requires making observations, recording data, and analyzing data in a form that can be duplicated by other scientists. In addition, the scientific method uses inductive reasoning and deductive reasoning to try to produce useful and reliable models of nature and natural phenomena. Inductive reasoning is the examination of specific instances to develop a general hypothesis or theory, whereas deductive reasoning is the use of a theory to explain specific results. In 1637 René Descartes published his Discours de la Méthode in which he described systematic rules for determining what is true, thereby establishing the principles of the scientific method.

Tactile Psychophysics

The mixture of sensitivities within a given patch of skin provides a basis for the concept of adequate stimulation. Sometimes, for example, a cold spot responds to a very warm stimulus, and one experiences what is called paradoxical cold. The sensation of heat from a hot stimulus presumably arises from the adequate stimulation of warmth receptors combined with the inadequate or inappropriate (although effective) stimulation of cold and pain receptors. The ability to detect pressure (i.e., pressure threshold) generally appears when a tension of about 0.85 gram per square mm (equivalent to about 1.2 pounds per square inch) of skin surface is applied on the back of the hand. Thus a force of 85 mg applied to a stimulus hair (or bristle) of 0.1 square mm is just about enough to elicit the experience of pressure. The energy of impact at pressure threshold is much greater than that required for hearing or seeing, the skin requiring approximately 100,000,000 times more energy than the ear and 10,000,000,000 times more energy than the eye. Differential pressure discrimination (the ability to detect just noticeable differences in intensity) requires changes of roughly 14 percent at maximum sensitivity. Adaptation to pressure is well known; one's awareness of a steadily applied bristle fades and ultimately disappears. As a result people are rarely aware of the steady pressure of their clothing unless movement brings about a change in stimulation. Most dramatic and perhaps best known among tactile experiences is adaptation to thermal stimulation. Continued presentation of a warm or cold stimulus leads to reduction or disappearance of the initial sensation and an increase in threshold values. Total obliteration of thermal sensation through adaptation occurs in the range from about 16 to 42 °C (61 to 108 °F). If one hand is placed in a bowl of hot (40 °C [104 °F]) water and adapted to that, and at the same time the other hand is adapted to cold (20 °C [68 °F]) water, then when both hands are simultaneously placed in lukewarm (30 °C [86 °F]) water, the previously cooled hand feels warm and the other hand feels cold. Both types of temperature receptors show adaptation. Cold receptors are characterized by an electrical discharge on sudden cooling, normally showing no response to sudden warming; similar electrical responses are produced by warmth receptors. Both receptors show steady discharges selectively depending on temperature; maximum discharge typically occurs between 38 and 43 °C (100 and 109 °F) for individual warmth receptors and between 15 and 34 °C (59 and 93 °F) for cold receptors.

smell

The nose is the organ responsible for the sense of smell. The cavity of the nose is lined with mucous membranes that have smell receptors connected to the olfactory nerve. The smells themselves consist of vapors of various substances. The smell receptors interact with the molecules of these vapors and transmit the sensations to the brain. The nose also has a structure called the vomeronasal organ whose function has not been determined, but which is suspected of being sensitive to pheromones that influence the reproductive cycle. The smell receptors are sensitive to seven types of sensations that can be characterized as camphor, musk, flower, mint, ether, acrid, or putrid. The sense of smell is sometimes temporarily lost when a person has a cold. Dogs have a sense of smell that is many times more sensitive than man's.

Tabula Rasa

The old philosophical notion that the mind is a clean slate or tablet (tabula rasa) until "written on" by impressions from the senses no longer seems fully tenable; infants, for example, show inborn (innate) ways of sensing or perceiving at birth. In its modern form, the problem of learned versus innate factors in sensory experience is studied in terms of the extent to which the genetically determined structure and function of sense organs and brain depend upon stimulation and experience for their proper maturation. Sensory deprivation in an infant's early life is increasingly being documented as detrimental to the full flowering of mature perceptual and intellectual functions. Since this sort of evidence may lend some support to the notion of the tabula rasa, modern researchers give credence both to nativistic (based on heredity) and empiricistic (based on learning) interpretations of human sensory function (see also learning theory).

outputs from the body

The outputs of the body include mechanical movements, radiant heat, sounds, minute electrical signals, as well as excretions and secretions that serve various biological functions. Some of these may serve as communication signals at a basic biological level, but verbal communication provides the greatest insights into the mind.

body language

The position of the body can indicate aggression, fear, or a whole spectrum of human attitudes. Crossed arms tend to indicate a reserved attitude or closed-mindedness, a slouch indicates disdain or carelessness, sweaty palms indicate nervousness, a weak handshake means lack of confidence, and a pale face or trembling are synonymous with fear. Facial expressions are produced by movements of the eyes, eyebrows, nose and mouth. Narrow eyes mean anger and widened eyes indicate surprise. A frown denotes concern, and pupils expand when something is of interest. A mouth with down-turned corners is sad; one with up-turned corners is a happy smile. Happiness, sadness, fear, anger, surprise, and disgust are facial emotions that are widely recognized around the world regardless of culture. These facial expressions are made with five facial muscles. The attire and hair styles that we wear also send messages which can be part of body language. Purple-dyed hair and body piercing indicate non-conformity, pin-striped suits just the opposite. Expensive jewelry, cosmetics, and perfume send a message of affluence. Beards, wigs, clothing, and cosmetics are all used to decorate our bodies to send conscious or subconscious messages to on-lookers.

Methodology for Subjective Perceptions.

The purpose of the scientific method is to establish "truths" that are evident to everybody using objective observations and rules of deduction. The Methodology for Subjective Perceptions provides a basis for working with events that are outside the domain of the scientific method. The Methodology is not intended to reveal universal truths. It is intended to solve problems and provide perspectives for each individual according to his or her abilities. The rules of logic remain the same. The rules of deduction remain the same, but the rules of evidence are subjective. Each person may have different individual perceptions. For example, a college student's record player was stolen. He called the police and described the lost record player as "brown". The record player was never found because it was actually "red". The student did not know that he was colorblind. What is "truth" for one person may not be so for another because each individual's perception is unique. A person's perception cannot be shared with anybody else except through communication. Communication is fallible, subject to exaggeration, falsification, and misinterpretation. In contrast to philosophies, religions, and ideologies dictated by some Authority, the Methodology for Subjective Perceptions encourages independent thinking. What we learn and who teaches us becomes important. As students, we can be accepting and unquestioning or we can be critical and questioning. When we are young, we are in the first category. We accept the opinions of others and adopt their philosophies without proof or questions. We can be easily manipulated or molded. When we grow up, we apply our minds to what we learn and we can judge and question our teachers, their teachings, and their motives. Our life experiences help to protect us from manipulation. We can only talk about teachers and their motives when we are discussing subjects of personal perceptions, philosophy, doctrines, or beliefs. In the hard sciences, where there are objective rules of evidence, students will eventually detect mistakes made by the teacher. In philosophy or religion, the teacher may have an agenda that includes your conversion to a cult or to make you believe an article of faith. Some of these indoctrination sessions may include isolation (sometimes called a "retreat") and deprivation of food/drink ("fasting"), or sleep. Other coercive techniques may include attempts to undermine an individual's self-confidence with statements like "You still don't know enough to make a judgement", "You need the talent or vision", "If you don't believe in this, your soul will be lost", "That opinion is heresy", etc. Words like "pagan", "infidel", "heretic", "heathen", and "gentile" are often used to subdue, alienate, and deride dissenting opinions. People frequently accept indoctrination because they are afraid to speak up, contradict, or challenge opinions stated with great conviction by distinguished persons or a "higher authority". Lack of confidence in one's own perception or ideas and the desire to avoid a conflict or confrontation are other reasons. Awareness of these manipulation techniques may prevent their being used on us. We have to develop reliance on our own senses and abilities. We would like to be like the child who asked "Why is the emperor walking around in his underwear?" when everybody else believed that the emperor was wearing a robe that only wise people could see. We cannot fall into a trap of agreeing with the point of view of someone else because they have a higher authority. We have to trust our own senses and judgement for things that cannot be objectively proved. The only reality that we are capable of perceiving is provided by our senses and our logic. We should strive to consider conventional physical explanations before jumping to hypotheses for which we have no basis. Some accounts of "poltergeists" that make noises in the walls in the middle of the night completely ignore the simpler explanation that the noises are made by nesting squirrels, birds, or raccoons. Are there facts that can be beyond our comprehension? Undoubtedly there are, but we should not believe anything that we cannot sense directly or indirectly or which is logically nonsensical. We also have to take a practical approach toward solving problems. Do you want to bend a key? Take some pliers and bend it. Do you want to move a saltshaker without touching it? Ask a friend to move it for you; the word "please" works wonders. Don't waste mental energy trying telekinesis if you have tried it for five minutes and nothing happened. Don't do things the hard way. It is said that faith can move mountains, but shovels have been proved to really work regardless of what you believe. Make sure that you really want to move the mountain before you start shoveling, though. Precognition is the ability to see into the future. Scientists have always been particularly incredulous of psychics' claims to be able to foretell events. However, if you would ask a scientist to tell you when the next lunar eclipse will occur, a prediction will be made. The prediction will be made by application of Newton's laws of gravitation to the orbital paths of the earth and the moon. Why shouldn't we be able to predict what people will do? People are subject to physical and chemical laws that influence their behavior. We can predict death. Life is 100% fatal. Everybody dies. Life insurance companies make it their business to try to predict how long people will live. Biologists assess health risks based on body weight, proportion of fat intake, and exercise habits. The groundwork is already there for making predictions about people. We need to extend the techniques of prediction into the mental area, the psychic domain. We need to develop psychical laws. Psychical laws would enable us to predict how a person would react under specific circumstances. The "laws" don't need to be perfectly accurate. Ninety percent accuracy might be practical enough. How do we do it? The reaction of a person depends on their personality and their previous experience. The person may not react twice in the same manner. At the outset, we would need to have substantial information about the person whose reaction we want to predict. If the person is cooperative, the information may be gathered by questionnaires or tests. Otherwise, deductions need to be made about the person's psychical constitution based on his or her past actions. In a later section, we will assess our own character traits and try to make some deductions about how these traits affect our own future actions and the actions of other persons possessing these traits.

taste anatomy

The receptors for taste, called taste buds, are situated chiefly in the tongue, but they are also located in the roof of the mouth and near the pharynx. They are able to detect four basic tastes: salty, sweet, bitter, and sour. The tongue also can detect a sensation called "umami" from taste receptors sensitive to amino acids. Generally, the taste buds close to the tip of the tongue are sensitive to sweet tastes, whereas those in the back of the tongue are sensitive to bitter tastes. The taste buds on top and on the side of the tongue are sensitive to salty and sour tastes. At the base of each taste bud there is a nerve that sends the sensations to the brain. The sense of taste functions in coordination with the sense of smell. The number of taste buds varies substantially from individual to individual, but greater numbers increase sensitivity. Women, in general, have a greater number of taste buds than men. As in the case of color blindness, some people are insensitive to some tastes.

scent of flowers

The scent of flowers and roots (such as ginger) depends upon the presence of minute quantities of highly odorous essential oils. Although the major odour constituents can be identified by chemical analysis, some botanical essences are so complex that their odours can be duplicated only by adding them in small amounts to synthetic formulations.

Approaches to the study of sensing

The science of the human senses is truly interdisciplinary. Philosophers, physicians, anatomists, physical scientists, physiologists, psychologists, and others all study sensory activities. Some of their earliest work was anatomical, an approach that continues to be fruitful. Physical scientists, particularly physicists and chemists, made important contributions to an understanding of the nature of stimulus energies (e.g., acoustic, photic, thermal, mechanical, chemical); in the process, they also performed many fundamental measurements of human sensory function. Hermann von Helmholtz, a 19th-century German scientist who was a physicist, physiologist, and psychologist, studied the way in which sound waves and light are sensed and interpreted. Modern studies of sensation have been enhanced by devices permitting the precise production and control of sensory stimuli. With other instruments, physiologists have been able to probe the electrical signals generated by sensory cells and afferent nerve fibres to provide a biophysical analysis of sensory mechanisms.

critical thinking

The scientific method relies on critical thinking, which is the process of questioning common beliefs and explanations to distinguish those beliefs that are reasonable and logical from those which lack adequate evidence or rational foundation. Arguments consists of one or more premises and one conclusion. A premise is a statement that is offered in support of a claim being made. Premises and claims can be either true or false. In deductive arguments the premises provide complete support for the conclusion. If the premises provide the required degree of support for the conclusion then the argument is valid, and if all its premises are true, then the conclusion must be true. In inductive arguments the premises provide some degree of support for the conclusion. When the premises of inductive arguments are true, their conclusion is likely to be true. Arguments that have one or more false premises are unsound.

Direct or Experimental evidence.

The scientific methods relies on direct evidence, i.e., evidence that can be directly observed and tested. Scientific experiments are designed to be repeated by other scientists and to demonstrate unequivocably the point that they are trying to prove by controlling all the factors that could influence the results. A scientist conducts an experiment by varying a single factor and observing the results. When appropriate, "double blind" experiments are conducted to avoid the possibility of bias. If it is necessary to determine the effectiveness of a drug, an independent scientist will prepare the drug and an inert substance (a placebo), identifying them as A and B. A second scientist selects two groups of patients with similar characteristics (age, sex, etc.), and not knowing which is the real drug, administers substance A to one group of patients and substance B to the second group of patients. By not knowing whether A or B is the real drug, the second scientist focuses on the results of the experiment and can make objective evaluations. At the end of the experiment, the second scientist should be able to tell whether the group receiving substance A showed improvements over those receiving substance B. If no effect can be shown, the drug being tested is ineffective. Neither the second scientist nor the patients can cheat by favoring one substance over another, because they do not know which is the real drug.

touch

The sense of touch is distributed throughout the body. Nerve endings in the skin and other parts of the body transmit sensations to the brain. Some parts of the body have a larger number of nerve endings and, therefore, are more sensitive. Four kinds of touch sensations can be identified: cold, heat, contact, and pain. Hairs on the skin magnify the sensitivity and act as an early warning system for the body. The fingertips and the sexual organs have the greatest concentration of nerve endings. The sexual organs have "erogenous zones" that when stimulated start a series of endocrine reactions and motor responses resulting in orgasm.

taste (gustatory) sense

The sensory structures for taste are the taste buds, clusters of cells contained in goblet-shaped structures called papillae that open by a small pore to the mouth cavity. A single taste bud contains about 50 to 75 slender taste receptor cells, all arranged in a banana-like cluster pointed toward the gustatory pore. Taste receptor cells, which differentiate from the surrounding epithelium, are replaced by new cells in a turnover period as short as 7 to 10 days. The various types of cells in the taste bud appear to be different stages in this turnover process. Slender nerve fibres entwine among and make contact usually with many cells. Taste buds are located primarily in fungiform (mushroom-shaped), foliate, and circumvallate (walled-around) papillae of the tongue or in adjacent structures of the palate and throat. Many gustatory receptors in small papillae on the soft palate and back roof of the mouth in adults are particularly sensitive to sour and bitter tastes, whereas the tongue receptors are relatively more sensitive to sweet and salty tastes. Some loss of taste sensitivity suffered among denture wearers may occur because of mechanical interference of the dentures with taste receptors on the roof of the mouth.

skin absorption

The skin acts as a protective barrier for the body, but it is not impervious. Many substances pass through the skin and can affect various organs of the body. When the skin is exposed to harsh chemicals, such as chlorine bleach or detergents, there may be just a local irritation or chemical burn. Organic solvents such as gasoline, mineral spirits, and dry cleaning fluids can be absorbed through the skin and reach toxic levels in the body. The liver is the organ most frequently damaged as it tries to detoxify these substances.

secretions and excretions

The skin is covered with many specialized glands that secrete sweat, sebum, smegma, and earwax. In addition there are glands that produce tears, saliva and milk. Sweat serves primarily to cool the body. However, the sweat of the underarms develops a strong smell when it ferments under bacterial action. Scientists have debated whether sweaty smell is supposed to be an attractant, a repellent, an indication of vigor, or serves other functions. The widespread use of antiperspirants and air conditioning has virtually eliminated this type of stimulus from our society. However, researchers at the University of California at Berkeley conducted an experiment where women sniffed a bottle containing androstadienone, a chemical found in male sweat that smells vaguely musky. Tests showed that the blood pressure, heart rate, breathing, and levels of cortisol in the women increased within 15 minutes of sniffing the chemical and remained elevated for more than an hour. The women also reported elevated mood and sexual arousal. Sebum and smegma are oily secretions that lubricate various parts of the body. They also have characteristic smells at close range to the body. The pubic area has a musky smell that may play a role in sexual stimulation. Excretions like urine and feces serve to carry away waste products of the body, but they also carry a lot of information about the body. From a sample of urine it is possible to determine the function of the kidneys, the presence of venereal or parasitic diseases, and whether a woman is pregnant. Feces can be used to identify dietary components, parasitic infections, the presence of ulcers, and many digestive functions. Menstrual fluids and semen are excretions of the body that are part of the reproductive cycle, but which can transmit disease-causing organisms from infected individuals.

scientific experiment

The subject of a scientific experiment has to be observable and reproducible. Observations may be made with the unaided eye, a microscope, a telescope, a voltmeter, or any other apparatus suitable for detecting the desired phenomenon. The invention of the telescope in 1608 made it possible for Galileo to discover the moons of Jupiter two years later. Other scientists confirmed Galileo's observations and the course of astronomy was changed. However, some observations that were not able to withstand tests of objectivity were the canals of Mars reported by astronomer Percival Lowell. Lowell claimed to be able to see a network of canals in Mars that he attributed to intelligent life in that planet. Bigger telescopes and satellite missions to Mars failed to confirm the existence of canals. This was a case where the observations could not be independently verified or reproduced, and the hypothesis about intelligent life was unjustified by the observations. To Lowell's credit, he predicted the existence of the planet Pluto in 1905 based on perturbations in the orbits of Uranus and Neptune. This was a good example of deductive logic. The application of the theory of gravitation to the known planets predicted that they should be in a different position from where they were. If the law of gravitation was not wrong, then something else had to account for the variation. Pluto was discovered 25 years later.

It is necessary to understand the limitations of our senses so that our mind will not be fooled, and it is necessary to understand the limitations of our mind so that we know when to trust our senses.

The two senses that we use the most are sight and sound. Touch is used in familiar situations. Smell is used in close quarters, and taste is used when we eat. Eyeglasses may influence what we see. Most glasses will filter out some part of the visible spectrum, specially tinted glasses or sunglasses. Yellow sunglasses, for instance, make it difficult or impossible to distinguish blue from green highway signs. White flowers and yellow flowers cannot be differentiated either. Wearing this type of glasses is like getting a case of color blindness. Glasses also create distortions or reflections, and they can fog, obscuring visibility. Noisy environments can impair hearing. Hearing aids, which sometimes become necessary for older people, do not yet have the ability to focus on the sounds that are of interest to their users.

breathing

The very act of breathing, which we have to do several times per minute, brings air into our lungs and whatever else is in the air. Our nose hairs filter out insects and some dust, but gases like carbon monoxide, vapors, smoke, pollens, bacteria, viruses, and small dust particles are carried into the lungs. The body has many self-cleansing mechanisms to keep the lungs clean, but constant exposure to air pollutants eventually take their toll on the lungs or other organs of the body. The tar and chemicals carried in the smoke of cigarettes has been linked to many types of respiratory disorders and nicotine has an addictive effect on the brain. Carbon monoxide produced by gasoline motors or charcoal fires in enclosed places interferes with the oxygen-carrying function of the blood and is responsible for many deaths each year. Paint solvents and gasoline fumes can damage the liver. Gases like nitrous oxide and vapors like ether affect the nervous system and are used as anesthetics.

olfactory quality

The vocabulary of odour is rich with names of substances that elicit a great variety of olfactory qualities. One of the best-known published psychological attempts at classification was in 1916 on the basis of more than 400 different scents on human subjects. On the basis of the apparent similarities of perceived odour quality or confusions in naming, it was concluded that there were six main odour qualities: fruity, flowery, resinous, spicy, foul, and burned.

taste

Theorists of taste sensitivity classically posited only four basic or primary types of human taste receptors, one for each gustatory quality: salty, sour, bitter, and sweet. Yet, recordings of sensory impulses in the taste nerves of laboratory animals show that many individual nerve fibres from the tongue are of mixed sensitivity, responding to more than one of the basic taste stimuli, such as acid plus salt or acid plus salt plus sugar. Other individual nerve fibres respond to stimuli of only one basic gustatory quality. Most numerous, however, are taste fibres subserving two basic taste sensitivities; those subserving one or three qualities are about equal in number and next most frequent; fibres that respond to all four primary stimuli are least common. Mixed sensitivity may be only partly attributed to multiple branches of taste nerve endings. In humans, tastes of sugars, synthetic sweeteners, weak salt solutions, and some unpleasant medications are blocked by gymnemic acid, a drug obtained from Gymnema bushes native to India. Among some laboratory animals, gymnemic acid blocks only the nerve response to sugar, even if the fibre mediates other taste qualities. Such a multiresponsive fibre still can transmit taste impulses (e.g., for salt or sour), so that blockage by the drug can be attributed to chemically specific sites or cells in the taste bud. In some animals (e.g., the cat), specific taste receptors appear to be activated by water; these water receptors are inhibited by weak saline solutions. Water taste might be considered a fifth gustatory quality in addition to the basic four.

heuristics

There are many types of heuristics employed by the mind as shortcuts for assessing information quickly. Several mechanisms of social cognition enable us to make inferences from social information. If you meet a used car salesman at a party, you may immediately feel distrust because the stereotype of used car salesmen is that they lie and cheat. The pattern-matching ability of the mind is exceptional, but it tends to perceive what it is seeking. If you are hungry, many things will remind you of food. If you are looking for a face you will find one, whether it is in the formations of the clouds, the print of a flowery towel, or the surface of the moon. In an experiment, horoscopes were distributed to persons attending a class. The students were told that each horoscope had been made especially for each of them, and they were asked to rate its correctness. Most participants agreed that the horoscopes were fairly accurate for each of them. The students were then asked to pass their horoscope to the person next to them. They were amazed to find out that all of them had received exactly the same horoscope. This willingness to apply a general description with no specific data to one's own life is called "subjective validation" and it results from our search for relevance in the information that we process.

Nerve supply

There is no single sensory nerve for taste. The anterior (front) two-thirds of the tongue is supplied by one nerve (the lingual nerve), the back of the tongue by another (the glossopharyngeal nerve), and the throat and larynx by certain branches of a third (the vagus nerve), all of which subserve touch, temperature, and pain sensitivity in the tongue, as well as taste. The gustatory fibres of the anterior tongue leave the lingual nerve to form the chorda tympani, a slender nerve that traverses the eardrum on the way to the brainstem. When the chorda tympani at one ear is cut or damaged (by injury to the eardrum), taste buds begin to disappear and gustatory sensitivity is lost on the anterior two-thirds of the tongue on the same side. The taste fibres from all the sensory nerves from the mouth come together in the medulla oblongata. Here and at all levels of the brain, gustatory fibres run in distinct and separate pathways, lying close to the pathways for other modalities from the tongue and mouth cavity. From the medulla, the gustatory fibres ascend by a pathway to a small cluster of cells in the thalamus and then to a taste-receiving area in the anterior cerebral cortex.

hans the horse

There was once a horse named "Hans" that was reputed to be able to solve arithmetic problems. When asked to multiply two times two, the horse would tap its hoof four times. The horse had a successful mathematical career until scientists started to study it. When the horse was separated from its trainer it lost its ability to solve problems. After some experiments, it became apparent that the horse observed the expression of the trainer and stopped tapping its hoof when the trainer looked satisfied and became relaxed. Some dogs have been found to sense on-coming epileptic seizures in people, and can be trained to get help. If animals can do it, people can do it too within the limits of their perception. The best palm readers can hold your hand and look at your face as they speak and thus feel your tensions and your emotions. They watch your pupils as they hold your hand and say "Let me see what you came to see me about ... love ... or work". Your reaction will give you away. The expression in your eyes, the dilation of your pupils, the tension of your hand, or the way you breathe can give a good observer clues about your interests. Besides, the palm reader is choosing two topics that are important to everybody. There is no way to go wrong! The polygraph, or lie-detector, automates the perception of these small clues to provide a more scientific basis for determining what a person is thinking about.

odourous substances

To be odorous, a substance must be sufficiently volatile for its molecules to be given off and carried into the nostrils by air currents. The solubility of the substance also seems to play a role; chemicals that are soluble in water or fat tend to be strong odorants. No unique chemical or physical property that can be said to elicit the experience of odour has yet been discovered.

verbal inputs

Verbal communication might have been included under sounds. However, the effect of verbal input on the mind is so different from that of the wind blowing or other noises encountered in nature that it is considered separately. Imagine that your boss calls you to his office and says something neutral like: "In two weeks we are having a meeting to discuss the progress of our new project". Your reaction may be one of anticipation or apathy. Not much is required from you except your participation. However, if the boss says something negative like: "You made several mistakes in your last report and I am very dissatisfied with your work". You may become angry or scared, your heart may start racing and you may want to justify what you did. Words have the power to make you laugh or the power to make you cry because they are not only sounds. Words have meanings that get to the root of your emotions. Since ancient times words have had mystical power because they could represent objects, feelings, curses, etc. The word "abracadabra" was supposed to have magical powers against disease or disaster, and sometimes it was carried in an amulet. Prayers were more than just words; they provided a way of communicating with the deities. Much can be deduced about the state of mind of a speaker from their speech. The tone of the voice can convey authority, fear, doubt, and many other different emotions.

air pressure

We can sense changes in air pressure as pain or discomfort in our ears, sinuses or bones. The nerves surrounding the body cavities that contain enclosed pockets of air detect volume changes caused by external air pressure.

eating and drinking

We have to eat and drink to sustain our life, but what we ingest can carry not only nutrients, but also substances that can adversely affect our health and mental processes. There are regions in the United States where there is a great prevalence of kidney stones that are associated with the hardness of the water. The "goiter belt" is another region where the soil has a deficiency of iodine that would result in thyroid gland problems were it not for iodized salt. Grain tainted with ergot fungus, which has an LSD component, has been theorized to have caused hallucinations responsible for the witch hunts in Salem, Massachusetts. We cook foods to make them more digestible and to kill harmful microorganisms and parasites. However, cooking may decrease the nutritional value of the food and charring during grilling may create nitrosamines that have been associated with some cancers. Our mass markets require the preservation of food by the use of food additives. Many of these preservatives were discovered by analyzing foods, such as cheese, which don't readily spoil. Other food additives are only used to improve appearance, e.g., artificial colors. Not all additives are harmful, but some people prefer to buy "natural" or "organic" products because they do not want to eat residual pesticides used in agriculture. Some "natural" and "organic" products may be quite harmful. Opium, coca leaves, marijuana, and tobacco are all natural products with addictive or mind-altering properties. This does not mean that they may not have legitimate medical uses. Opium has been the source of morphine, which is a powerful pain killer. Caffeine, which occurs naturally in coffee, tea, and chocolate, is a nervous system stimulant and also a diuretic. Large amounts of caffeine can cause tremors or shaking. Caffeine can be addictive for some people even in small amounts. It is not by coincidence that soft drink manufacturers use caffeine as an additive. If you drink more than one cup of coffee, tea, chocolate, or cola drink per day you may be addicted to caffeine. This can be easily verified by abstaining from caffeine-containing foods or drinks for a couple of days. Restlessness, sinus pressure, or headaches are common withdrawal symptoms.

magnetic fields

We live immersed in the magnetic field of the earth. The human body is generally not affected and cannot detect this magnetic field. Homing pigeons, however, have been shown to use the earth's magnetic field as one means for returning home. In principle, however, the electrical activity of the nervous system could be affected by strong magnetic fields, and recent experiments suggest that magnetic fields may help to reduce certain kinds of pain.

sleeping

We spend approximately one third of our life sleeping. What does the mind do during this time? Why do we need so much sleep? Encephalographic (EEG) research has shown three distinct patterns of electrical activity of the mind: awake, asleep, and dreaming. Studies of sleeping subjects have identified different stages of sleep. Dreaming occurs only during some of these stages, and there is evidence to believe that other mammals besides man dream. Sleep refreshes the organism. Dreaming is thought to be caused by perceptions and ideas to which a person is exposed during waking hours. Some people use a technique of "problem immersion", which is to study a problem and its possible solutions in excruciating detail for several days, to force the dreaming mind to examine solutions that may not be apparent to the conscious mind. Dreaming seems to take disconnected ideas and permute them regardless of whether it is logical to do so or not. Feasible solutions are sometimes obtained. Many scientists have reported that their great ideas have been conceived in dreams. Inspiration and creativity may result when these processes occur while we are awake. Some dreams may be caused by fears or other needs. You may dream that your arm has been infested by bees that are making holes in it, only to wake up and find your arm tingling because the circulation stopped as you were lying on it. Some schools of psychiatry use dreams as a portal into the mind of a patient and try to interpret dreams as a way to help patients overcome their problems. Mystics view dreams as visions into the future or revelations from God. The book of Genesis provides at least four instances of dreams being used by God or his messengers as a means for communicating with people.

What do the modern sensory catalog now include beside the five senses?

Yet the modern sensory catalog now includes receptors in the muscles, tendons, and joints, which give rise to the kinesthetic sense (that is, the sense of motion), and receptors in the vestibular organs in the inner ear, which give rise to the sense of balance. Within the circulatory system, sensory receptors are found that are sensitive to carbon dioxide in the blood or to changes in blood pressure or heart rate, and there are receptors in the digestive tract that appear to mediate such experiences as hunger and thirst. Some brain cells may also participate as hunger receptors. This is especially true of cells in the lower parts of the brain (such as the hypothalamus) where some cells have been found to be sensitive to changes in blood chemistry (water and other products of digestion) and even to changes in temperature within the brain itself. sensory receptionHuman sensory reception.Encyclopædia Britannica, Inc. A horizontal cross section of the human eye, showing the major parts of the eye, including the protective covering of the cornea over the front of the eye.Encyclopædia Britannica, Inc.

Ancient philosophers

called the human senses "the windows of the soul," and Aristotle described at least five senses—sight, hearing, smell, taste, and touch. Aristotle's influence has been so enduring that many people still speak of the five senses as if there were no others.

argumentative evidence

consists of evaluating facts that are known and formulating a hypothesis about what the facts imply. Argumentative evidence is notoriously unreliable because anybody can postulate a hypothesis about anything. This was illustrated above with the example about the "channels" of Mars implying intelligent life. The statement "I heard a noise in the attic, it must be a ghost" also falls in this category.

psychophysics

embraces the study of the subjective aspects of sensation in terms of objective stimulus energies. One of the oldest and most classical approaches to the study of sensation, psychophysics includes the study of people's reports of their sensations when they are stimulated: of their ability, for example, to match tones of equal loudness, to detect stimulus differences, and to estimate sensory magnitude or intensity under conditions of controlled stimulation. Psychophysical research continues as an active enterprise particularly among modern psychologists.

chemoreceptors

for chemical odours

Mechanoreceptors

for distortion or bending

thermoreceptors

for heat

Photoreceptors

for light

nociceptors

for painful stimuli

What is important for us is not the biological structure of the brain

hat is important for us is not the biological structure of the brain, but rather what it is capable of doing. The totality of the conscious and unconscious functionality of the brain and central nervous system is called the mind and, sometimes, the psyche. The mind is a storehouse of information. Some of this information is learned and some of it is carried as part of our genetic constitution. Our senses provide input that is analyzed, interpreted, and stored in our mind. Sometimes the input from the senses conflicts with what the mind knows to be true. These illusions are common with sight. If we look at a grid of white lines on a black background, the eye perceives gray spots at the intersections of the horizontal and the vertical lines. Straight parallel lines drawn equidistant to a point from which straight lines radiate will be seem to curve away from the point. On the stage a magician says, "The hand is quicker than the eye", and proceeds to apparently pull cards out of thin air. Indeed, an image in the eye persists for about 1/30th of a second leading to many illusions. Still pictures projected at thirty frames per second are perceived as continuous motion and provide the foundation of the television and the movie industry.

theories

he scientific method requires that theories be testable. If a theory cannot be tested, it cannot be a scientific theory. Testing of scientific ideas can include the classical experimental method, replication, attempted refutation, prediction, modeling, inference, deduction, induction and logical analysis. Step 2 involves inductive reasoning, as described above. This approach can be used to study gravitation, electricity, magnetism, optics, chemistry, etc. Sometimes more than one theory can be proposed to explain observable events. In such cases, different predictions made with each theory can be used to set up experiments that select one theory over another. In the 17th century there were competing theories about whether electromagnetic radiation, such as visible light, consisted of particles or waves. At the beginning of the 20th century Max Planck postulated that energy can only be emitted or absorbed in small, discrete packets called quanta. This seemed to favor the particle theory, particularly after Einstein demonstrated that light behaves like a stream of particles in photoelectric cells. However, diffraction experiments with electrons, which were considered particles because they had a measurable weight, showed all the characteristics of waves. In 1926, Erwin Schrödinger developed an equation that described the wave properties of matter, and this became the foundation for the branch of physics called quantum mechanics.

The Zamora Personality Test uses ten categories for individual attributes:

i1) Achievement attitudes - degree of motivation toward goals.E.g., ambitious, determined, unmotivated, persistent. i2) Emotional temperament - emotions that rule our lives.E.g., cheerful, high-strung, insecure, morbid. i3) Energy level - the degree of effort that we use in our daily life.E.g., lethargic, passive, energetic. i4) Intellectual factors - characteristics of our minds.E.g., imaginative, logical, observant, inattentive. i5) Material attitudes - how we regard our environment.E.g., wasteful, spiritual, thrifty. i6) Maturity - our level of experience and wisdom.E.g., knowledgeable, naive, resourceful. i7) Philosophical attitudes - our preferred ways of thinking.E.g., idealist, pessimistic, inflexible. i8) Physical attributes - how we regard our body.E.g., insane, old, sleepy, suicidal. i9) Risk attitudes - degree of concern for oneself.E.g., cautious, impulsive, adventurous. i10) Task performance attitudes - approaches toward problem solving.E.g., planner, methodical, neat, impractical.

pain

is the least understood among all of the human senses. The pattern of stimulation is more crucial in pain than in any other sense. A single brief electric shock to the skin or to an exposed nerve may not elicit the experience of pain; yet it tends to become painful upon repetitive stimulation. Cutaneous pain is often sensed more sharply than is pain associated with deep tissues of the body (e.g., viscera). Certain areas of the body are relatively analgesic (free of pain); for example, one can bite shallowly into the mucous lining of the cheek without discomfort. The organs of the abdominal cavity are usually insensitive to cutting or burning, but traction or stretching of hollow viscera is painful (as when the stomach is distended by gas). Pain also displays sensory adaptation, although the process appears to be more complex than it is for other sensory modalities. Thus, the intensities of headaches, toothaches, and pains from injury often show cyclic fluctuations, possibly from such factors as changes in blood circulation or in degree of inflammation. The visceral pains, those of dental origin, or of diseased tissues can be reduced by analgesic medications, which tend to be less effective on cutaneous pain. Pain has a strong emotional context. In certain cases, after frontal lobotomies (a type of brain surgery) have been performed, a person may report that he still feels the pain of a pin prick or other irritation but that he does not find it as disturbing or emotionally disruptive as he did before the lobotomy. Many phenomena indicate the powerful role of the brain and spinal cord in sensing potentially painful sensory input. According to one theory, a gate control system in the spinal cord modulates sensory input from the skin to determine whether the input is perceived as painful. This theoretical formulation also may account for moment-to-moment fluctuations in the intensity of perceived pain despite the absence of any stimulus change. Such brain-mediated factors as emotional tension or past psychological experiences are thought to influence pain perception by acting upon this spinal gate control system.

Human sensory reception

means by which humans react to changes in external and internal environments.

beyond the five sense organs

n addition to sight, smell, taste, touch, and hearing, humans also have awareness of balance (equilibrioception), pressure, temperature (thermoception), pain (nociception), and motion all of which may involve the coordinated use of multiple sensory organs. The sense of balance is maintained by a complex interaction of visual inputs, the proprioceptive sensors (which are affected by gravity and stretch sensors found in muscles, skin, and joints), the inner ear vestibular system, and the central nervous system. Disturbances occurring in any part of the balance system, or even within the brain's integration of inputs, can cause the feeling of dizziness or unsteadiness.

The interpersonal and social attributes also consist of ten categories:

s1) Aggressiveness - measure of camaraderie between people.E.g., cruel, friendly, rude, thoughtful. s2) Control attitudes - mechanisms by which we influence others.E.g., argumentative, diplomatic, domineering, gentle. s3) Dependability - factors that affect trust in others.E.g., disloyal, insincere, obedient, trustworthy. s4) Egocentrism - selfishness and selfish attitudes.E.g., arrogant, envious, humble, proud. s5) Emotional expression - ways of expressing inner feelings toward others.E.g., cold, congenial, exuberant, hateful. s6) Fairness - how we judge others.E.g., appreciative, disrespectful, objective. s7) Leadership attributes - features that make us stand out in a group.E.g., brave, convincing, independent. s8) Physical appearance - how we view ourselves physically.E.g., attractive, stylish. s9) Regard for Rules - obedience for the laws of society.E.g., dishonest, ethical, law-abiding, criminal. s10) Team Spirit - attitudes toward working with people.E.g., loner, political, family-oriented.

itching

seems to bear the same relation to pain as tickle does to pressure. The experience usually lasts long enough to demand attention and (like tickle) normally leads to a response such as rubbing or scratching the affected area. A number of skin disorders are accompanied by itching, presumably from a fairly low level of irritation in the affected area (which also may be produced in undiseased skin). While a single shock by a low-intensity electrical spark normally produces no sensation, a repetitive pattern of such shocks may induce an itch similar to that produced by an insect bite. Itching also may occur as an aftereffect of the sharp pricking sensation produced by single strong shocks, presumably because the nerves continue to produce a patterned afterdischarge following the cessation of the stimulus.

heat

the body generally maintains a temperature of 37° Celsius (98.6° Fahrenheit). The testicles require lower temperatures for sperm production. Fever is a pathological condition where an abnormally high body temperature is sustained. Temperatures higher than 42.5° C (108° F) kill human cells.