Psychology Midterm 1
Perception
product of bottom-up and top-down processing
7 main neurotransmitters
(1) Acetylcholine (ACh): learning, memory, muscle (damage: Alzheimer's, paralysis) (2) Dopamine: arousal, mood states, thought processes, physical movement (damage: Parkinson's disease, remove craving but not desire) - L-dopa: can pass through blood-brain barrier but excess can lead to schizopherina (3) Serotonin: arousal, mood, sleep, eating (4) Norepinephrine: arousal, mood, sleep, eating (damage: mood disorders) (5) GABA (gamma-Aminobutyric acid): main inhibitory neurotransmitter and keeps the brain from becoming too aroused (lowers anxiety) (damage can lead to epilepsy) (6) Glutamate: the main excitatory neurotransmitter in the nervous system and memory storage, pain perception (excessive can excite neurons to death, but lower levels can lead to a coma) (7) Endorphins: pain relief and feelings of pleasure (natural painkillers), play a role in the placebo effect (exception can release endorphins)
2 sets of brain structures
(1) Central core: brain stem and structures near the brain stem (cerebellum, thalamus, basal ganglia) (2) Limbic system: hypothalamus, hippocampus, and amygdala (plays an important role in our survival, memory, and emotions)
2 major parts of the nervous system:
(1) Central nervous system (brain and spinal cord: totally encased in bone for protective reasons and surrounded by cerebrospinal fluid for cushioning) (2) Peripheral nervous system: remainder of the nervous system and links the CNS with the body's sensory receptors, muscles, and glands
2 functions of the spinal cord:
(1) Conduit for incoming sensory data and outgoing movement commands to the muscles (2) Provides for spinal reflexes, simple automatic action not requiring involvement of the brain such as the knee-jerk reflex or the withdrawal reflex - Most spinal reflexes however go through the brain. Sensory neurons connect with -> interneurons, which connect with -> motor neurons - However, the brain is usually not involved in the reflex. The brain can stop a spinal reflex by sending commands to override it, but it chooses not to.
3 types of descriptive statistics:
(1) Correlation coefficient: describes the results of a correlational study (2) Measures of central tendency: mean (most commonly used), median (used with unusually high or low scores), mode (3) Measure of variability: range, standard deviation (average extent that scores vary from the mean of the distribution)
3 basic parts of a neuron
(1) Dendrites: receives the signal; fibers that project out of the cell body (unmylinated gray matter) (2) Cell body: houses the nucleus and other structures to keep the neuron alive; decides whether or not to pass the information received from the dendrite to the axon (gray matter) (3) Axon: a long singular fiber that sends the signals and transmits to another neuron via vesicles and neurotransmitters (transmits not to just 1 neuron but to multiple neurons)
3 main research methods
(1) Descriptive: observational, case studies, survey (only allows researcher to speculate about cause-effect relationships) (2) Correlational (3) Experimental
Observational Method
(1) Naturalistic Observation: behavior is observed in its natural setting without the researcher intervening in the behavior being observed (to prevent the unnatural behavior that might occur in laboratory due to social-regard principle) - to describe objectively and thoroughly the behaviors - be observational studies of animals and humans in public settings such as the workplace, school, and bars - limitation to observational techniques is that the observer may influence to change the behavior of those being observed: observers must be as unobtrusive as possible (2) Participant Observation: when the observer becomes part of the group being observed - observer may become part of the group being observed, as with Diane Fossey and her study of gorillas. She began accepted into the group of gorillas. However, this is the exception rather than the norm. Usually observers start as a participant, like an undercover detective
2 types of brain cells
(1) Neurons: size varies (e.g. longest is spinal cord to toes) (2) Glial cells: remove waste product of neurons, stabilize, and insulate neurons via the myelin sheath (90% of brain cells)
2 types of brain scans:
(1) PET (positron emission tomography) scan: - a harmless does of radioactive glucose (sugar) is introduced into the bloodstream. The glucose moves to the areas that are more active because those neurons need more nutrients and blood sugar. - when the glucose is metabolized by the neurons, it emits positrons, atomic particles emitted by radioactive substances. - computer can detect the positrons. The more active areas have brighter colors than less active areas. So, we can tell which areas are more active and more involved, when a person does a task like reading or talking (2) fMRI (functional magnetic resonance imaging): - more active areas in the brain have more oxygen and subsequently blood flow increase. The computerized image shows the variation in blood flow. Oxygenated and non-oxygenated blood have different magnetic - does not require reactivity, sharper picture, good for localization and seeing active areas (bad to see immediate effects because it takes a couple seconds for blood to move)
2 types of visual receptor cells:
(1) Rods: responsible for dim light and achromatic vision - Rods outnumber cones about 20 to 1. Rods are only in the periphery. - There are several rods for one bipolar cell and so the information that the rods send are average, but this is useful in dim light conditions. - Rods are useful for dark adaption, the process by which the rods and cones through internal chemical changes become more and more sensitive to light in dim light conditions. (2) Cones - Cones are more centrally located in the retina than the rods. - They are in the fovea, a tiny pit in the center of the retina and in the periphery of the retina on each side of the fovea. Here, the bipolar and ganglion cells are pushed aside for the rods and the cones. - In normal or brighter light, cones are mainly responsible for vision and object should be focused on the fovea. - Cones tend to have more direct routes than the rods to the bipolar and ganglion cells for the retinal information. Hunting birds tend to have more cones than rods.
How do we know how fast neural transmission is (brief)?
(1) We can take a neuron from an animal or cadaver. Then, we can use a volt meter and attach the two nobes to each side of the neuron. Then, we stimulate the neuron and time the speed. (2) Behavior way
2 types of action potential signals
(1) excitatory: makes the neuron more likely to fire (2) inhibitory: makes the neuron less likely to fire - if excitatory signals outweigh the inhibitory signals, the action potential will fire
2 types of statistics:
(1) inferential: how to interpret the results of experimental studies (2) descriptive: describe the data of a research study in a concise fashion
3 types of neurons:
(1) interneurons: integrate information within the CNS by communicating with each other and are only in the CNS (2) sensory neurons: carry information to the CNS from sensory receptors (such as the rods and cones in the eyes), muscles, and glands (enter the CNS through the spinal cord and some enter the brain directly through holes in the cranium) (3) motor neurons: carry movement commands from the CNS out to the rest of the body (exit the CNS through the spinal cord or from the cranium)
2 types of explicit memory
(1) semantic memory: memory for factual knowledge (e.g. remembering George Washington is the first president, remembering the name of your high school) (2) episodic memory, memory of personal life (e.g. remembering your first kiss) (most fragile, most likely to be impaired by an accident)
Why are there more receptors than ganglion cells?
(1) the optic nerve would be too big (2) the ganglion cells are more sensitive because it receives more input from multiple rod receptors.
Motor and Somateosensory cortex similiaries
(1) there is specificity; a given region corresponds to a specific region in the body (2) there is a map; in the cortex, body parts close to each are typically close in the cortex (3) there is proportional representation; more sensitive parts get more stimulation than other parts such as fingers
Auditory Pathway
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Temporal Integration Procedure
- 2 random meaningless dot patterns are presented sequentially at the same visual location with a brief time delay between them. - 2 dots when put together produces a meaningful pattern. If people can see the meaningful pattern, it implies the existence of sensory memory.
Opponent-process theory
- 3 cell systems that help us see color at the post-receptor level of processing (along the pathway from the bipolar cells to the brain: ganglion cells and thalamus and visual cortex cells - systems are the pairs: red-green, blue-yellow, and black-white. If one is stimulated in the system, the other one is inhibited. - For instance, in the blue-yellow opponent-process cells, some are stimulated by blue light and inhibited by yellow light and vice versa - complementary colors explain why we do not see reddish green because the complementary colors cancel each other out - explains complementary color afterimages. We believe afterimages are from cone fatigue. For instance, fatigue in red cones causes to fatigue and under-base line firing
Trichromatic theory of color vision
- 3 different cones that are receptive to different colors, activated best by short, medium, or long wavelengths or light, roughly corresponding to blue, green, and red - assumes that these colors make up all of the colors we see. If all the cones are equally active, we see white - played a role in the creative or the television screen, which consists of red green, and blue dots. This confuses the retina - additive mixtures, not subtractive mixtures - difficulty explaining why complementary colors such as red-green and blue-yellow produce white instead of reddish-green or bluish-yellow or complementary-color afterimage
What is the purpose of a control group in an experiment?
- A control group does not experience the experimental manipulation in a study. - The group receiving experimental manipulation is then compared to the control group to see if there are any differences in the dependent variable(s). - For example, in an experiment that is testing the efficacy of a new drug, the experimental group would receive a drug and the control group would receive a placebo. - The control group should be as similar to the experimental group as possible except in the difference you are interested in.
Pop-out effect
- Attention is like a spotlight. Some things are easy to get access to, but others are not. - Pop-out effect: easily finding a different feature in similar features. It becomes harder to keep track of more features, and we have to start searching sequentially.
How did we discover the primary visual cortex receptive fields?
- Blakemon and Cooper grew up cats in a horizontal striped environment. They found that whenever an object was in a horizontal stripe-type orientation, the cat's neuron will fire more. Also, few cortical cells (V1) would respond preferentially to vertical strips - conclusion is that perhaps the brain has to grow cells and based on the environment, the brain grows cells best suited to the environment. Or the brain prunes away unused cells. Either early experiences, especially atypical ones, are important in developing cells.
Pitch Overall
- Brain uses firing rate to differentiate the low frequencies, and the location of maximal hair cell activity to distinguish high frequencies.
Bipolar cells
- receptive fields are center-on, center-off - For center-on bipolar cells, they are depolarized when light is on the center and hyperpolarized (inhibited) when light is in the surround.
Association cortex
- Dorsal: neurons in the parietal association cortex, superior and middle temporal visual association cortex - identifies where things are and how to interact with them (match-to-location task) - Ventral: neurons in the inferior temporal visual association cortex - identifies what things are (match to sample task) - Blind-sight: DF has his dorsal path but not his ventral path
What is EEG and what is it used for?
- EEG stands for electroencephalography and it is a method used to study the brain. - Electrodes are placed on the scalp (it is a noninvasive procedure) and voltage changes in the brain are measured as a proxy for brain activity. - ERP ("event-related potentials") are measured in a technique in which EEG signals are carefully evaluated with respect to the timing of some stimulus event, like the presentation of a word in a sentence.
Born with 1 cone
- If you are born with 1 cone and you get 60% color, you don't know if it is one cone's favorite firing or another cone's medium firing. - There is ambiguity between the hue (wavelength) and the intensity (firing frequency). -These people perceive a generic brownish color.
Born with 2 cones
- If you are born with 2 cones, when you get to the minimum, or base line firing, of 1 of the cones, then it's as if you have 1 cone. - You cannot compute an accurate ratio because again, we don't know if the firing cone is firing for its favorite or second favorite color. - For these people, they can distinguish one color such as blue or yellow but the other colors are a brownish color. - The brain doesn't have enough information to do a better job.
Does learning change your brain?
- In an experiment, owl monkeys were given 1 banana pellet per every 10 - 15 seconds for touching a textured rotating disk, a task that is not natural to them. They did this for a fairly long time (90 minutes per day and for 3.5 months). - Jenkins and Merzenich put electrodes in the monkey's somatosensory cortex and measured the receptive field neurons correlated to each finger stimulation before and after training. They did this by probing different parts of the monkey's hand and finding out which part of the somatosensory cortex is firing. - They discovered that this experience caused a greater part of the somatosensory cortex be devoted to the fingers that touch the textured rotating disk (3 times larger than before training and the receptive fields are smaller, meaning that the monkey is more sensitive to tactile stimulation in those areas). - However, other areas in the somatosensory cortex were reduced. You don't get something for nothing.
What is unique about the fovea?
- In most of the retina, one ganglion cell receives signals from dozens and dozens of photoreceptors. - However, in the fovea, one ganglion cell receives signals from only one photoreceptor. - This is why visual acuity is greatest at the fovea. - Also, there are essentially only cones (no rods) at the fovea.
Light strikes the eye. Describe the path this information follows from the pupil to the occipital lobe.
- Light passes through the pupil, and is focused by the lens onto the retina. - The light passes through other cells (ganglion cells and bipolar cells) to reach the receptor cells (rods and cones) on the back of the retina. - The light is transduced into a signal passed to the bipolar cells and then the ganglion cells. - The axons of the ganglion cells form the optic nerve, which brings the signal to the thalamus (specifically, the Lateral Geniculate Nucleus, a part of the thalamus), which passes the signal back to the occipital lobe.
What substance speeds propagation of the action potential? Describe how this substance speeds conduction of the action potential down the axon.
- Myelin is a fatty substance composed of glial cells that wrap around the axons of neurons. - If an axon is myelinated, ions can only move into or out of the axon at the nodes of Ranvier, gaps on the axon in between myelin cells. - As a result, the action potential skips from node to node which allows the action potential to move more quickly (up to 120 m/sec).
Why does everything start to look gray at dusk?
- Our retina contains two types of sensory cells: rods and cones. - The rods are sensitive to light, and the cones are sensitive to color of light. - When light hits these cells, it is turned into neural information that is transmitted to the ganglion cells. - A hundred or so rods will transfer information to just one ganglion cell. - This enables us to pick up even the smallest amounts of light. - Conversely, only about six cones converge to one ganglion cell, making our cells that detect color way less sensitive to light. - This is why when there is less light, things start to look grayer. Our sensitivity to color (via our cone cells) has lessened in the dark.
3 sections of the ear
- Outer: pinna (collects sound and funnels them through the auditory canal to the tympanic membrane the eardrum: produces vibrations) - Middle: malleus, incus, and stapes - Inner: oval window displace fluid within the cochlea, which causes movement of the basilar membrane and thus movement of the hair cells in the membrane. - cochlea in the inner ear contains the receptor cells for hearing - tiny hair cells that line the basilar membrane are receptors for hearing. - auditory message is coded according to how these tiny hair cells move, and the motion gets translated into neural impulses that get passed on to the auditory nerve cells that carry the information to the thalamus, which directs the information to the primary auditory cortex in the temporal lobes.
Prosopagnosia vs Capgras delusion
- Prosopagnosia is the inability to recognize people by looking at their face only. - Capgras delusion is the belief that friends and family members are replaced by impostors.
What are the absolute and difference thresholds? How are they defined, and why are they defined that way?
- The absolute threshold is the minimum amount of energy in a sensory stimulus that can be detected 50 percent of the time (answering the detection question). - The difference threshold is the minimum difference between two stimuli that can be detected 50 percent of the time. - Both of these are statistical definitions. Both must be defined this way because, contrary to original predictions, there is no abrupt point at which humans switch from being unable to detect a stimulus or difference to being able to detect it.
What is the visual pathway for human?
- Retinal receptors (rods and cones) project to bipolar cells (which we didn't talk about much) and thence to ganglion cells (which we did). - The axons of the ganglion cells then converge to form a bundle of fibers called the optic nerve. - Leaving the eyeball, the optic nerve carries information to the lateral geniculate nucleus (LGN) in the thalamus. - Projections from the LGN take the signal to primary visual cortex. - Information about the left side of the visual world (that is, the things to the left as you are looking ahead) is sent, via the thalamus (LGN), to the right visual cortex (at the rear of the head, in the occipital lobe). Information about the right side of the visual world is sent to the left visual cortex. - The "cross point" for the neural fibers is called the optic chiasm. - This allows for communication across the hemispheres. Within the visual cortex, information passes from one area to the next (V1 to V2 ...)
What is the difference between rods and cones?
- Rods are used primarily in the dark (low levels of light) and cannot perceive color. - They saturate very quickly in bright light. - Cones are involved in the perception of brighter light. They are responsible for color vision.
What is the difference between the two basic types of visual receptors in terms of function and trade-offs? What evolutionary problems or benefits might arise in life if you only had one or the other?
- Rods are useful in low-light contexts, but they do not distinguish color and aren't useful in bright light. In the daylight, rods are saturated and so don't provide any useful information. - Cones are useful in normal lighting conditions, and together they distinguish colors. - Rods greatly outnumber cones (around 20:1) and they are located throughout the retina, but are essentially absent in the fovea. - The highest density of cones occurs at the fovea. When you look straight ahead to examine something, you're bringing your foveas to bear on that thing.
The somatosensory and motor cortices share common organizational properties in how they represent different parts of the body. In the context of these brain regions, define the concepts of specificity, the "neural map" or "topographic map," and proportional representation.
- Specificity: Specific areas of these cortices neurally represent specific parts of the body. Put another way, the representation for a part of the body is not distributed all across the cortices, but rather it is localized to a particular area. - Neural Map/Topographic Map: Body parts are represented in a roughly orderly manner in the brain--parts of the cortices representing the fingers are near parts of the cortices representing the palm of your hand, representations for lips are near the representations for your tongue, et cetera. - Proportional Representation: Different parts of the body have larger or smaller areas of the brain that represent them. The amount of "real estate" a part of the body has in these cortices is not directly proportional to how big that part of the body is. Rather, it is proportional to how much information is transmitted by the peripheral nervous system about that body part--in other words, how much information the brain needs to get about that particular body part. This is related to the function of the body part. For example, fingers must be sensitive and able to make fine discriminations, and thus there are both a high concentration of sensory neurons in the peripheral nervous system and in the brain representing parts of the fingers.
What have researchers learned from so-called split-brain patients, who have had their corpus callosum severed?
- Split-brain patients still have functioning hemispheres, but the information from both hemispheres is not coordinated. - The corpus callosum, which connects the left and right hemispheres, allows the hemispheres to communicate with one another - left hemisphere largely controls the right side of the body and the right hemisphere controls the left side of the body. In terms of vision, the right hemisphere sees the left visual field and vice versa - left hemisphere is more involved with language function and the right hemisphere is more involved with spatial processing. - However, this is a matter of relative rather than absolute involvement
What is Signal Detection Theory?
- The ability to detect a faint sensory stimulus (the signal) involves both a person's physiological sensitivity to the stimulus and their decision-making criterion, which is based on non-sensory factors like personality. - People may have the same physiological sensitivity to a given sensory stimulus, but report different answers as to whether they saw (heard, felt, smelled or tasted) the stimulus based on their decision criterion. There are four possible events that can occur when testing a person's signal detection: 1) Hit: the person was presented with a stimulus and they report the stimulus 2) False Alarm: the person reports a stimulus, but there was no stimulus 3) Miss: the person does not report a stimulus, but a stimulus was presented 4) Correct Rejection: the person does not report a stimulus and no stimulus was presented
Feature Detectors
- recognize elementary features that are eventually put back together into the whole object that can be recognized: separate processing systems for form, color, distance, and motion information - blind-sight: a condition in which a blind person has some spared visual capacities in the absence of any visual awareness. - People with blindsight respond to a visual stimulus without consciously experiencing it.
Describe the auditory pathway in humans
- The auditory system is a mechanical vibration system. - Hair cells receptors are located in the basilar membrane of the cochlea. - Incoming sound waves cause vibrations by displacing fluid in the cochlea. - This displacement causes movement of the hair receptor cells. - The movement of the hair cells sends action potentials down the auditory nerve, through the thalamus, to primary auditory cortex where the information is interpreted.
What are the detection, difference, and scaling questions?
- The detection question asks: what is the minimum amount of energy in a stimulus that humans can detect? - The difference question asks: what is the minimum difference in stimulus energy between two stimuli that humans can detect? - The scaling question asks: How are human perceptual scales of measurement related to physical scales of measurement?
What is the trichromatic color theory? What is the opponent-process theory? Where in the visual processing system do the processes explained by these theories take place (hint: composite theory explains this).
- The trichromatic color theory posits that there are three types of cones. Each of these types is activated by a specific range of wavelengths of light, these ranges roughly corresponding to blue, green, and red. These colors combine in an additive manner, meaning the combination of the three is white. (This is in contrast to subtractive mixtures, like paint, where combining the colors makes black). - Thus, the range of colors that we see are the result of the proportion of activity from these three cones. - The opponent-process theory proposes three cell systems - red-green, blue-yellow, and black-white - in which stimulation of one member of the pair inhibits activity of the other. - The composite theory says both of these theories are active, such that color is processed by the cones in the retina according to trichromatic color theory, and information is processed at the post-receptor cell level (e.g. thalamus, visual cortex) according to opponent-process theory.
Theoretically, how could fMRI be used for communication by a paralyzed patient who cannot speak but can understand language?
- Theoretically, if someone could make distinct brain regions "light up" on an fMRI scan (i.e. perhaps the motor cortex would "light up" when imagining swinging a tennis racquet, and the parahippocampal gyrus would "light up" when imagining walking within one's house), they could associate these things with a "yes" or "no" answer and use these thoughts to communicate when asked yes or no questions. This has actually been done, on a limited scale, in one patient.
Primary Visual Cortex Receptive fields
- They respond well to rays of light that are oriented in a particular direction. - Simple cells are cells whose receptive field respond to light with a specific orientation. - usually have a on center band marked by two off side bands that respond to darkness. - When light is not on the on band precisely, the stimulus is not as effective for the cell.
An fMRI study showed that brain activity in the prefrontal cortex predicted a response above chance levels, at moments coming before subjects were even aware of their decisions. What does this suggest about our subjective conscious experience?
- This study shows that decision-making may involve subconscious processing and that the basis of at least some of our decisions may be beneath our awareness. - Even if the decision is one that we think we are making using our conscious deciding powers.
What is top down processing and how does this relate to illusions?
- Top-down processing is the brain's use of knowledge, beliefs, past experience, expectations, etc. to interpret incoming sensory information. - This can lead to the ignoring of what that sensory information is actually revealing. - For example, the Cornsweet Illusion discussed in class. Your brain interprets the dark area below the cube as a shadow and thus uses knowledge of shadows to create the illusion that the top cube is darker than the bottom.
Explain how you could build a simple circuit to detect motion at a given rate and direction in a given spot in the visual field.
- Two neurons, A and B, detect an object in neighboring receptive fields. - Neuron A connects to a neuron - call it D - which then connects to neuron M. It takes additional time for a signal to pass through neuron D. - Neuron B connects directly to neuron M. - Neuron M requires the simultaneous excitatory input of two neurons to fire. - Thus, if an object passes through the receptive field of A, it will activate A, and that signal will get slowed down passing through neuron D, and eventually stimulate M. - Meanwhile, as the object passes through the receptive field of B, it will activate neuron B, which will then (quickly) stimulate M. - If the timing is right - that is, if the object is moving at the right rate - M will receive input from neurons D and B at the same time, and will detect the motion. - Thus, M is tuned to motion at a given rate, in a given direction, in a specific spot in the visual field. This is (a simplified version of) a Reichardt detector.
Describe Weber's Law and Stevens's Power Law
- Weber's Law- our ability to perceive a difference is relative to the constant background intensity. For example, when a room is dimly lit, lighting one candle will make a noticeable difference. When a room is brightly lit, adding another candle will not be noticed. - Stevens's Power Law- the perceived magnitude of a stimulus is equal to the actual physical intensity raised to some constant power for each type of sensory judgment. Our perception of a stimulus magnitude does not match the actual physical world. This may be an adaptation enhancing our survival (increase perceived intensities of dangerous stimuli).
Group X has higher blood pressure than group Y, and this difference is statistically significant. What does this mean?
- When a finding is statistically significant, it is unlikely that the result happened by chance alone (i.e. the effect is unlikely to be a fluke). - This does not mean that the result is important, though. When research reports say that a result is "significant", they are usually referring to significance in the limited statistical sense and not asserting that the finding is important or practical.
Wavelength and cone process
- When receiving a particular wavelength, the cone that best fits it will fire the most, then the next cone will fire a medium amount, and the last cone will either fire minimally or at base rate. - For instance, for an intense yellow hue with love wavelengths, the short cone will fire at the base line rate; the medium will fire a lot, and the long will fire the most. - system then takes in count the amplitude and frequency of the cone's firing, and the ratio of the firing tells us the color. - More intense colors are due to more frequency, even though you get the same wavelength frequency ratio
How do we achieve position constancy despite moving our eyes and heads?
- When we move our eyes or turn our head, we unconsciously compute the shift in the retinal image that our own motion will produce - we will cancel out this amount of movement in interpreting the visual input. In this way, we are able to perceive objects as having position constancy.
How did we find out about the homuncili for the motor and somateosensory strips?
- Wilder Penfield applied mild electrical simulation via a single electrode to a patient's brain before performing surgery for epilepsy - originally try to see where seizures originate and symptoms such as bright lights before seizures
How does color vision work for humans? What are the theories that try to explain color vision?
- You can see colors because the combinations of firing rates of different cone cells can unambiguously define the hue and intensity of an object. - If we only had one cone, then when it fired at, say, 50% of its maximum rate, we wouldn't be able to tell if the object we're looking at is intensely illuminated at a "dispreferred" hue for that cone; or less intensely illuminated for a more preferred hue. - When you have two or more types of cones with different "preferences" for hue, then the ratio among them, and the absolute firing rates, make this unambiguous, as long as the color being viewed is within the range where this ratio would be meaningful (i.e., where neither cone is at its minimum). - We need three cones for normal vision rather than just two, because the sensitivity of the long-wavelength-preferring cones falls off to near zero at short wavelengths, and the sensitivity of the short-wavelength-preferring cones falls off at long wavelengths. - With just two cones, these more extreme hues would not be distinguishable because then for these hues only the medium-wavelength cone would be firing, leading to hue/intensity ambiguity.
Agonist
- a drug or poison that increases the activity of one or more neurotransmitters - Dopamine: amphetamine (continually stimulate and release dopamine), cocaine (blocks reuptake of dopamine) - Selective serotonin reuptake inhibitors (SSRI): drugs that selectively block the reupatke of serotonin (selectiveness prevents crashes) - Selective serotonin and norepinephrine reuptake inhibitors (SSNRIs) - GABA: antianxiety drugs like tranquilizers (increasing GABA lowers anxiety), alcohol - Endorphin: morphine and heroin (triggers dopamine reward system and release dopamine)
Hypothesis
- a proposal for further investigation, initially based on limited evidence
Scatterplot
- a visual depiction of correlational data in which each data point represents the score on the 2 variables for each participant
Detection
- absolute threshold is the minimum amount of energy in a sensory stimulus detected 50 percent of the time (no abrupt transition point); equal probability of being detected or not detected
Explain the "all or none" law of neuronal firing.
- all action potentials have the same strength and speed regardless of the triggering stimulus - when a stimulus is strong enough to depolarize the neuronal membrane, the neuron produces an action potential or "fires". - action potential will be the same size and propagated at the same speed regardless of the strength of the initial stimulus
Action Potential Overall
- all-or-nothing event: either an impulse or not - intense stimuli causes more neurons to fire and more frequenctly
Long-term memory
- allows storage of information for a long period of time and its capacity is essentially unlimited - 2 types: (1) explicit (declarative memory): memories we have to recall consciously and make declarative statements about (2) implicit (non-declarative memory): memories that don't require conscious recall or declarative statements
Wernicke's area
- an area in the cerebral cortex responsible for comprehension of speech and text - in the left temporal lobe of the majority of people, regardless of handedness - Damage to this area leads to incoherent speech and the inability to understand the speech of others and to read. It functions as the understanding center
Third-variable problem
- an explanation of a correlation between 2 variables in terms of another (third) variable that could possibly be responsible for the observed relationship between the 2 variables - correlation is necessary but not sufficient for causation to exist - e.g. as self-esteem decreases, depression increases: 3rd variable could be a biological predisposition for both low self-esteem and depression
Parietal lobe
- area behind the central fissure and above the lateral fissure (multimedia center) - where information from different senses is integrated (creates a coherent picture of the whole - right part of the parietal lobe is involved in spatial layouts and taking care of the general body such as getting into a car with heels and moving the entire body in coordination - left part is involved in precise skilled movements and control such as playing the violin, geometric thinking, and mathematics - one lobe in which the right and left parts are different - houses the somatosensory cortex
Broca's area
- area in the cerebral cortex responsible for fluent speech production - in the left frontal lobe of the majority of people, regardless of handedness - Damage to this area leads to the inability to generate fluent speech but can understand speech and read silently. However, they can sing but cannot sign
Frontal Lobe
- area in the front of the central fissure and above the lateral fissure) involved in planning, decisions, predictions, and overall "higher functions" - keeps you from doing whatever the habitual action is. For instance, if you are driving to your friend's house, which is near your school, it prevents you from driving to your school rather than your friend's house - has the motor cortex
Occipital lobe
- area located in the lower back of each hemisphere - manages vision - the smaller your primary visual cortex, the more dramatic some visual illusions appear - location of initial processing of visual information and passes to the association cortex
Myelin sheath
- glial cells and an insulating layer of a white fatty substance - speeds up action potential because action potential cannot travel in myelinated regions: jumps from Node of Ravier to Node of Ravier - damage causes multiple sclerosis (body attacks myelin) and neural transmission becomes ineffective: difficulty moving - develops over time: not born with it
What did Descartes say about the mind-body problem?
- argued that the mind and body are discrete (separate) - proposed that the body was like a hydraulic machine with "animal spirits" in place of the water and the nerves as the pipes. - Animal spirits traveled through the body and ultimately ended up in the pineal gland, which worked like a kind of valve system for directing the animal spirits and effecting action. - thought that that reflexes, pain, pleasure, and recall were functions of the body. - Descartes believed that the function of the soul (mind) was to think, to reason. The soul also acts in the pineal gland; in this gland the "animal spirits" (body) and soul interact. - Descartes' view on the mind-body problem was not well received but it highlighted the important question of how the mind may influence the body. - His solution cannot be right, but any dualist belief system must acknowledge that there has to be a way for the soul/spirit and the body to interact.
Thalamus
- as a relay station for incoming sensory information except for smell (goes directly from the receptors in our nose to the cortex)
Retinotopic
- as the visual pathway goes on, it becomes less retinotopic - We do not always want information to be retinotopic, meaning if the retina moves, the object placement moves. - Presumably, our less retinotopic information is resolved by a bunch of neurons, and the brain determines what the image is by the pattern of neuron firing. - In the monkey, some cells fired more for specific images (e.g. may fire most for office chairs and umbrellas but fire under base line for cars and elephants). Then, we present the object a little off-center and find that the cells fire a little less if the image is off-center. This tells us our information is to a degree retinotopic. - many neurons fire for a concept or person with surprising specificity
Echoic memory
- auditory sensory memory - can repeat auditory information that we took in for a couple seconds
Dualism
- body and the soul are different entities - Thomas Aquinas (1225 - 1274), a Christian (who was highly esteemed by Pope Innocent IV), believed that the soul can exist apart from the body. The soul lives on forever. - Descartes: mind-body dualism: the mind could exist without the body and vice versa - Descartes believed that the body is about reflexes. For instance, when the foot feels fire. He believed that the first and the subsequently animalistic spirit would travel through tubes up to the pineal gland. There, the animalistic spirit would interact with the soul to decide what to do. Then, the message would run down the tubes, and the foot would pull itself away from the fire. This is very mechanistic thinking - while the body was responsible for passions such as pain, pleasure, and recall of images and memories, the soul was responsible for intelligent and complex thinking such as planning and making decisions
Top-down
- brain's use of knowledge, beliefs, and expectations to interpret the sensory information - comes from the brain the sensory structures. Subjective nature of perception is due to this top-down processing
Jean-Dominique Bauby
- by fMRI scan: locked-in syndrom • In an fMRI scan, we ask comatose people to imagine that they are swinging their arm to hit a tennis ball. Thinking about an action typically activiates the brain areas such as the motor areas. 4/23 showed significant responding on imagery tasks. • Then, in a communication task, we ask questions to a comatose people by having them respond "yes" by imagining swinging a tennis ball and "no" by imagining walking through a familiar place. 1 patient had a 5/6 significant correct response. • The fMRI established the patient's ability to communicate.
Correlational studies (calculations)
- calculate a correlation coefficient, which tells us the strength (absolute value of the number) and type of relationship (positive or negative sign) between the two variables - A positive correlation, which indicates a direct relationship between the two variables, has a positive sign. As one variable increases, the other variable increases, and vice versa. For instance, height and weight has a positive correlation - A negative correlation, which indicates an inverse relationship between the two variables, has a negative sign. As one variable increases, the other variable decreases, and vice versa. For example, grades and time watching television has a negative correlation.
Somatic Nervous System
- carries sensory input from receptors to the CNS - relays commands from the CNS to the skeletal muscles to control their movements - primary neurotransmitter is acetylcholine - controls the voluntary
Ganglion cells
- center-surround receptive fields: center-on and center-off - For center-on ganglion cells, they fire more action potential (frequency) when light is on the center and fire less when light is in the surround.
4 lobes
- central fissure (runs down the center of each hemisphere) and the lateral fissure (runs along the side of each hemisphere) divides the lobes 1) frontal lobe 2) parietal lobe 3) occipital lobe 4) temporal lobe
Hormones
- chemically similar to some neurotransmitters, but neurotransmitters are released their target (the neuron), but hormones travel through the bloodstream to reach their targets
Meta-analysis
- combines the results for a large number of studies on one experiment question into one analysis to arrive at an overall conclusion
Association Cortex
- consists of all the areas of the cerebral cortex except for those devoted to primary sensory or motor processing - where higher-level processing occurs - fusiform face area in the association area (right-hemisphere specialization) plays an important role in prosopagnosia, face blindness
Cerebral Cortetx
- control and information-processing center for the nervous system - physically envelopes all of the other brain structures, except for the lowest part of the brain stem and cerebellum - two hemispheres are separated on top but joined together by the corpus callosum, a bridge of neurons that allow the two hemispheres to communicate - crumpling allows more cortical surface area to fit
Split-brain patients
- corpus callosum is cut and there is no communication between the hemispheres - left hemisphere sees Clooney and the right hemisphere sees Gosling. Because speech and language centers are in the left hemisphere, they can identify and say Clooney, but the right hand will point to Gosling
Conduction deafness
- damage to the mechanical system carrying the auditory information to the cochlea - hearing aids can alleviate this type of deafness
You would like to study the effect of reading on vocabulary acquisition in 6-year-olds. What are your dependent and independent variables?
- dependent variable is vocabulary acquisition (the outcome) - independent variable is reading (the potential cause of the outcome).
Operational definition
- description of the operations or procedures that the researcher uses to manipulate or measure a variable - e.g. aerobic exercise: type and duration of the activity - clarifies an experimenter's definitions of variable and allows other experimenters to attempt to replicate the experiment more easily
Chemical neural communication
- end of action potential cause tiny vesicles contain neurotransmitters (naturally occurring chemicals in our nervous system that transmit specialized information) to open into the synaptic gap - neurotransmitters enter receptor sites and that neuron fires - some neurotransmitters are destroyed by enzymes and others go through reuptake, taken back into the axon terminal of the sending neuron so that it can be used again
Nocebo effect
- expectation of a negative outcome due to treatment leads to adverse effects - not studied as much because of ethical reasons (difficult for doctors to inform of side effects)
What is fMRI and how does it work?
- fMRI stands for functional magnetic resonance imaging. - This technique allows scientists to study brain activity (with more spatial resolution than EEG: you get more detail about where things happen in the brain). - fMRI measures the amount of blood oxygen flow in the brain; areas with more neural activity demand greater blood flow. - Oxygenated blood can be detected because of the way its hemoglobin responds to the magnetic fields in MRI.
Sympathetic Nervous System
- fight-or-flight response and in control when we are aroused (prepares us for defense) - leads to accelerated heartbeat and inhibited digestion.
Weber's law
- for each type of sensory judgment we can make, the measured difference threshold is a constant fraction of the standard stimulus value used to measure it - smaller constant means that smaller differences can be detected for that type of sensory judgment: loudness has a smaller constant than light. - does not hold for very low or high intensity stimuli - means we notice proportional differences and not absolute differences
Inferential stasistics
- for experimenter to conclude that there is a placebo effect, reduction of anxiety in the placebo group would have tot be significantly greater than the reduction for the control group - statistical analyses that allow researchers to draw conclusions about the results of a study by determining the probability that the results are due to random variation (statistically significant if probability is 0.05 or less) - statistical significance does not insure practical significance but ensures that the result did not occur by chance
Measure of Retrieval
- frequency of exposure factors into how well you remember something but it requires attention - Recall is a measure of retrieval that requires the reproduction of information with essentially no retrieval cues (e.g. short-answer, essay questions) - Recognition is a measure of retrieval that only requires the identification of the information in the presence of retrieval cues (e.g. multiple-choice, matching) - Relearning: measure of the amount of time saved when learning information for the second time. The forgetting curve shows the greatest amount of forgetting occurs quickly and then tapers off.
Frequency theory
- frequency of the sound wave is mimicked by the firing rate of the hair cells across the entire basilar membrane. - For instance, if frequency were 100 Hz, the firing rate for the membrane would be 100 impulses per second. This is true, especially with low pitches.
Peripheral nervous system
- gathers information for the brain about the external and internal environment through sensory nerves - sends the brain's commands to the rest of the body through motor nerves - 2 parts: somatic nervous system and the autonomic nervous system
3-stage model of memory
- general model, although it is not completely accurate. (no neural system for short-term memory) - However, in general, information enters from the physical environment through our senses into sensory memory and flows from sensory memory to short-term memory to long-term memory and then back to short-term memory when we need to use it.
Nerve deafness
- hearing loss caused by damage to these hair cells or auditory nerve fibers - cause by aging and continued exposure to extremely noises - more difficult to treat than conduction deafness
LGN
- here, the brain begins to reconstruct the image from the receptive fields of the cells of the retina - 6 layers. 3 layers are for the right eye and 3 are for the left eye because to see in 3-D, you need to know which information goes to the left and right. - neurons are monocular and have concentric (center-surround) receptive fields - mostly terminate in V1
External Validity
- how practical your findings are and how well they can be generalized or applied to everyday life
Temporal lobe
- important in hearing and language processing - auditory cortex is the location of the initial processing of hearing information and passes to the association cortex
Placebo effect
- improvement due to the expectation of improving because of receiving treatment - placebo: an inactive pill or a treatment that has no known effects
Experiment Design
- independent variable: hypothesized cause the experimenter manipulates it (e.g. aerobic exercise) - dependent variable: the variable that is hypothesized to be affected by the independent variable (e.g. level of anxiety) - experimental group: group exposed to the independent variable - control group: group not exposed to the independent variable - (sometimes) 2nd control group or placebo group: to control for placebo effect (e.g. fake antianxiety drug) - double-blind procedure: a control measure in an experiment in which neither the experimenters nor the participants know which participants are in the experimental or in the control
Medulla, pons, midbrain
- involved in basic functions such as respiration, blood pressure, digestion, swallowing, and heart-beating - serve as a passageway for neural signals to and from higher areas in the brain.
Hippocampus
- involved in memory formation - generate new neurons through neurogenesis: discovered this through BrdU that is integrated into the DNA of cells preparing to divide and can mark new cells
Cerebellum
- involved in the coordination of our movements, our sense of balance, and motor learning - involved mostly in fine motor control and coordinated actions such as playing the violin - Alcohol depresses the functioning of the cerebellum
How do we know how fast neural transmission is (behavior)?
- isolate step 2 - line up 5 people so that there are 4 connections. When he hears the signal, the first person squeezes the next person's shoulder. When the last person has his shoulder squeeze, he signals it by saying it. Then, we record this time. Then, we repeat this with ankle squeezing - time for shoulder squeeze = time the first person hears the signal + 4 * (neural speed of the shoulder and brain + the decision making time to squeeze the other person's shoulder + neural speed of the brain and the hand + the squeezing time) + the reporting time - time for ankle squeeze = time the first person hears the signal + 4 * (neural speed of the ankle and brain + the decision making time to squeeze the other person's shoulder + neural speed of the brain and the hand + the squeezing time) + the reporting time - ¼ (time of ankle squeezing - time of shoulder squeezing) = neural speed of the ankle to brain - neural speed of the shoulder to brain - (distance between ankle and brain - distance between shoulder and brain)/ (neural speed of the ankle to brain - neural speed of the shoulder to brain)
Implicit memory
- long-term memories that influence our behavior but does not require conscious awareness - 3 types: (1) procedural (2) classical conditioning (3) priming: an earlier stimulus that influence the response to a later stimulus, is also an implicit memory because it is independent of a person's conscious memory
Amygdala
- major role in regulating emotional experiences, especially negative ones such as fear, anger, and aggression - generates quick emotional responses without cortical involvement
Flashbulb memories
- memories people have following a traumatic or extremely emotional effect - Idea: special memory process that's different when you are faced with an extremely emotional effect - Maybe evolution gave us a special learning mechanism that give us access to rich, detailed memories that are traumatic - But these memories don't seem to work this way: seems that flashbulbs memories are not as accurate as everyday memories, but even though they are wrong, people really believe in their flashbulb memories
Short-term memory/ working memory
- memory stage in which the recognized information from sensory memory enters consciousness - average number of items you can remember across a series of memory span trials, is 7 + or - 2 (5 - 9) chunks of information. A chunk is a meaningful unit in memory - less than 30 seconds: how long information can stay in the short-term memory if we cannot attend to it. We found this ask by presenting distractor tasks; a small amount of information is presented and then the participant is distracted from concentrating on the information for a brief interval of time
What might a neuroscientist argue about the mind-body problem, taking a materialist perspective?
- might argue that the mind and body are both controlled by the brain - Neural processing and signaling controls behavior (body) and thoughts (mind). - Our experience of consciousness arises from brain processes working in tandem to provide a unified experience.
Difference Threshold
- minimum difference between 2 stimuli detected 50 percent of the time, or just noticeable difference
Reticular formation
- network of neurons running up the center of the brain stem and into the thalamus, which controls our different levels of arousal and awareness
Where did we discover the idea that the different parts of the brain have different functions?
- originally Franz Gall's idea based on feeling parts of the heat - Broadmann
Hindsight bias
- the tendency, after learning about an outcome, to be overconfident in one's ability to have predicted it. Even a pair of opposite research conclusions can both seem obvious such as opposites attract and birds of a feather flock together. Be careful of what you think you know.
Signal Detection Theory
- our ability to detect a faint sensory signal (stimulus) is a decision-making process that depends upon a person's physiological sensitivity to the signal and upon a person's decision-making criterion, which is based on non-sensory factors - A mother may hear the baby crying but not a noise of similar volume. Doctors may be more likely to be accurate when looking at an X-ray to determine whether a faint spot indicates cancer because it's a high cost. - Researchers presented people with either a signal of constant faint intensity or no signal. There are 4 possible responses: hit, false alarm, a miss, or correct rejection. - A person can change his decision criterion to lessen the cost. The bottom line is that our perception of even a faint signal is a subjective process impacted by non-sensory factors.
Basal Ganglia
- outer sides of the thalamus and mainly is involved in initiation and execution of physical movements - low dopamine activity here can result in Parkinson's disease
Somateosensory Cortex
- parietal lobe strip of cortex directly behind the central fissure in each hemisphere - body senses and input about temperature and pain and information from muscles and joints that allow us to monitor the positions of the various parts of the body - contralateral relationships between the somatosensory strips and sides of the body - amount of space within these strips is allocated in accordance with the sensitivity of the body part
Hypothalamus
- part of the brain that regulates basic drives such as eating, drinking, and having sex - directs the endocrine glandular system through the pituitary gland and the automatic nervous system to maintain the body's internal environment (e.g. temperature, internal regulation)
Free Recall Tasks
- participants given a list of words and then asked to recall them in any order they wish - primacy effect: the superior recall of the early portion of the list due to constant rehearsal - recency effect: superior recall of the latter portion of the list due to sensory member; typically fades over time
Stevens's Power Law
- perceived magnitude of a stimulus is equal to its actual physical intensity raised to some constant power - constant power is different for each type of sensory judgment - Lessening our perception of dramatic increases in sensory intensities such as light and loudness serve as protective function for our eyes and ears, - increasing the perceived intensities of dangerous stimuli like electric shock would alert us to possible dangers.
Percentile rank
- percentage of scores below a specific score in a distribution of scores (never can have 100)
Iconic memory
- photographic memory for less than a second. - Because we cannot attend to everything that gets recognized, the register fades and is quickly forgotten. - how old movies work. There is an image, then a blank screen, and then another image. The sensory memory fills in the blanks
Bottom-up
- refers to the processing of incoming sensory input as it travels up from the sensory structures to the brain. It comes from the senses up to the brain - listening a foreign language: bottom-up processing tells you sounds, but you cannot interpret this input because you do not have top-down processing
Autonomic Nervous System
- regulates the functioning of our internal environment (controls the involuntary: stomach, lungs, and heart) - 2 parts: sympathetic nervous system and the parasympathetic nervous system
Maintenance rehearsal
- repeating the information in short-term memory over and over again in order to maintain it. - This is how we remember things without structure (ineffective because the system is easily damaged)
Case studies
- researchers try to learn as much as possible about a person, usually someone born or suffering from a specific deficit or problem - main goal of a case study is gather information that can treat the patient - limitation to case studies is that because the study is so specific to the patient, the results cannot be generalized. However, case studies do allow researchers to develop hypotheses - One example of a case study is Henry Molaison, a person who developed amnesia after an accident. H. M. had his hippocampus surgically removed, and he couldn't form new memories, leading scientists to think that the hippocampus is important in forming new memories.
Action Potential Process
- resting state is -70 millivolts: K+ is inside the axon and Na+ is outside the axon in a 2:3 ratio - when the neuron is about the fire, the membrane becomes more permeable to the sodium ion and diffusion causes sodium to rush in - positive charge causes the next section to be active - refractory period that prevents the same neuron from firing too rapidly: determines maximum frequency - then, membrane becomes permeable to potassium ion, which rushes outside due to concentration gradient - special ion pumps restore the ions back to its original conditions
Psycholgoy
- science of behavior and mental process - tries to understand ourselves and others, to solve problems that arise on a human-scale (such as addiction, language acquirement, etc.), and to understand all aspects of both our observable behavior and internal mental processes - tries to understand the cause of our behavior
Sperling and sensory memory
- showing participants a 3x3 set of letters and then presenting a tone after the letters disappeared. Each pitch will signify a different row, and then participants would have to recall the letters. Then based on how much letters the participants remember, the sensory store would be 3x that or the entire matrix because the participant would have to sense the entire matrix to report just 1 row. - The reason the study is designed like this is that if we try to have the participants repeat everything they remember, as they remember, the other letters from their sensory memory would be leaking out.
Levels of prcessing
- simplistic physical level: letters in "brain" - acoustic level: how "brain" sounds - semantic level: what "brain" means - Tulving esented groups with different tasks: (1) press a button if in CAPS, but not in caps (15%) (2) press a button if rhymes with "train" (47%) (3) press a button if it makes sense in the sentence "He saw a ______ in the street" (81%). The participants did not know this would be a free recall experiment and it shows the depth of processing. If you have to process something more intensely, you'll remember it more.
Sublimal
- stimuli detected less than 50 percent of the time; no empirical evident for subliminal persuasion - sensory input can be registered without our conscious awareness but such perception is short-lived and doesn't seem to have consequential, long-term impact on our behavior
Motor Cortex
- strip of cortex directly in front of the central fissure in each hemisphere and allows us to move different parts of our body - 2 strips are related by controlling the voluntary movement of the opposite side of the body - amount of space allocated to a specific body part in the motor cortex is not related to the actual size of the body part but to the complexity and precision of movements of which that part is capable. Fingers get more space than our torso - seen in the homunculus; the body parts are arranged in a toe-to-head fashion spanning from the top of the motor strip to the bottom
Correlational studies (overview)
- study how two variables, any factor that has more than value (e.g. grades, height, weight), and how they correlate, or are related, with each other - need a representative sample, or random sampling - correlation does not imply causation, although it can lead to a hypothesis
Parasympathetic Nervous System
- takes over after the sympathetic response. It leads to slowed heartbeat and pupil contraction - rest-and-digest system
Epiphenomenalism
- the belief that mental events are caused by physical events in the brain, but have no effects upon any physical events. Behavior is caused by muscles that contract upon receiving neural impulses - Libet's experiments
Retrograde amnesia
- the disruption of the memory for the past, especially episodic information of events before the trauma. However, amnesic can form new implicit memories
Anterograde amnesia
- the inability to form new explicit long-term memories following surgery or trauma to the brain. - Patient H.M. had severe epilepsy. Surgery removed his hippocampus and some surrounding tissue including part of medial temporal lobe and amygdala. - He could not form new explicit (declarative) memories but had short-term memory and implicit memories. He experienced semantic priming.
Black and white square illlusions
- the middle sections, the surround-off inhibits only above and below, while the surround-off in between the corners inhibits from 4 sides. Hence, the center seems bright top and bottom, but dark left and right. Hence, we see the middle as especially bright - We can see the contour of the image because the outlines seem to be high contrast as seen by the right, an evolutionary advantage. However, this also leads to illusion.
Frequency Distribution
- the number of participants receiving each score for a variable - Normal distribution: mean, median, and mode are all equal and percentage falling within a certain number of standard deviation of the mean is set - right-skewed: unusually high scores (mode, then median, then mean) (peak near left) - left-skewed: frequency distribution in which there are some unusually low scores (mean, median, mode) (peak near right) - want a right skewed distribution for life expectancy for a disease
Experiment
- to control for effects of third variables, researchers conduct an experiment in which they manipulate 1 variable and measure its effect upon another variable while controlling other potentially relevant variables - control from: (1) hold other variables constant (2) random assignment: randomly assigning the participants to groups in an experiment in order to equalize participant characteristics across the various groups in the experiment - random sampling also used
Survey
- uses questionnaires and interviews to collect information about a particular demographic - goal is to generalize its result to the population, the entire group of people being studied: needs random sampling or the results will be skewed (e.g. Shere Hite's sample in which she interviews women from women's organizations and political groups about their beliefs about romance: skewed) and too time-consuming and expensive to survey the entire population - Random sampling ensures that each person in the population has an equal chance of being selected to complete the survey. - limitation of surveys that we must assume that people answer the questions accurately: wording, order, and structure of the survey questions may lead to (unconsciously) wrong, or exaggerated, answers (for instance, the social desirability bias, our tendency to respond in socially approved ways)
Static picture moving illusion
- watching a film moving up, and then we see a static picture of a waterfall moving down. - One reason may be that when watching the film moving up, the neurons fire up, become fatigued, and thus, fire below their resting state. - Thus, we perceive the static picture moving down because there is an imbalance between faster down neurons and slower up neurons. - This may be evolutionary important because noticing change is important. Note: this isn't just an eye fatigue because when you shut and then open the eye, it still happens.
Left and right hemisphere specialization
- we always use both sides of the brain; they work together, connected by the corpus callosum - left specializes at mathematical skills, logic, and speech: focuses on the smaller details - the right is better at spatial perception, drawing, and facial recognition: gets the big picture - Patients with right hemisphere damage can only remember the A's (which compose an H), and those with left hemisphere damage can draw the H - there is no forced separation of labor as in the split-brain patient in normal people
Invariance problem
- we can recognize items (such as an actual car, a cartoon car) as one category even though they are not. This may be because we have specific neurons for particular concepts, or a collection of neurons fire for specific concepts
Sensory memory
- where we temporarily store incoming sensory information from the physical environment until we can attend to it, interpret it, and move it to the short-term memory through encoding
Endocrine system
- works with the autonomic nervous system in response to stress - communicates through messengers in the bloodstream - endocrine glands secrete chemical substances within the body into the bloodstream such as hormones (controlled by the hypothalamus) - exocrine glands secrete substances outside the body such as sweat and tears.
Antagonist
-a drug or poison that decreases the activity of one or more neurotransmitters. - Glutamate: alcohol blocks reuptake and dampens the frontal lobe
Visual Pathway Basics
1) Light travels through the pupil 2) Focuses on the retina 3) Hits the rods and cones (absorbed by photopigments: create patterns of neural impulses) 4) Hits the bipolar and ganglion cells 5) Optic Nerve: axons of the ganglion cells bundled together, exit the eye carrying the information along the visual pathways to the brain (blindspot where the optic nerve exits) 6) LGN/ thalamus 7) Visual cortex/ occipital lobe 8) Association cortex
7 types of top-down processing
1) Perceptual set: when we interpret an ambiguous stimulus in terms of how our past experiences have "set" us to perceive it. 2) Contextual effect: use the present context of sensory input to determine its meaning. The addition of contextual information provides top-down processing that allows the brain to resolve such ambiguities in normal perception (e.g. cornsweet illusion) 3) Figure and ground principle: Gestalt perceptual organizational principle that the brain organizes sensory information into a figure or figures (the center of attention) and ground (the less distinct background) 4) Closure: tendency to complete incomplete figures to form meaningful objects ((subjective contours: lines or shapes that perceived to be present but do not really exist) (infants see them: suggesting brain is hardwired to make sense of information) 5) Perceptual constancy: perceptual stabilize of the size, shape, brightness, and color for familiar objects seen at varying distances, different angles, and under different lighting conditions 6) Depth perception: involves the judgment of the distance of objects from us (major binocular cue is retinal disparity, the difference between these two views of each retina provides information about the distance of an object from us) 7) Monocular cues: linear perspective (as parallel lines recede from us, they appear to converge), interposition (if one object partially blocks our view of another, we perceive ti as closer)
4 types of false memories
1) Source misattribution: attributing a memory to the wrong source, resulting in a false memory (common in plagiarism) 2) Imagination inflation is increased confidence in a false memory of an event by repeatedly imagining the event because of mirror neurons. Actually perceiving something and imagining it activates the same brain areas. 3) Observation inflation effect is a false memory by believing yourself to do something by seeing another person do it. 4) Misinformation effect is the distortion of a memory by exposure to misleading information. This is what happened in the Elizabeth Loftus study.
How to encode:
1) automatic processing: occurs subconsciously and does not require attention (e.g. driving, reading: requires much practice) 9) Effortful processing is processing that occurs consciously and requires attention (e.g. studying).
Why is it difficult to know the corresponding locations for specialized functions?
1. Activity in one part of the brain causes activity in many parts of the brain because different types of skills goes into an activity. 2. We are not sure which tasks are in elemental portions or broken up. For instance, mathematics is broken down into smaller parts.
Examples of major injuries:
1. Auburtin's patient, who attempted suicide by shooting off the top of his skull. Because the lesion was in the front, if you press on the front part of the brain with a spatula, the person would stop talking. 2. Broca had a patient called Leborgne, who had selective speech impairment, and he and Auburtin found post-mortem a lesion in his brain. This helped Broca discover the Broca's area, even though Auburtin found it first. 3. Phineas Gage had a lesion in his frontal lobe and a different personality after his injury. This was evidence that certain regions of the brain have specialized functions. 4: Modern equivalent: lesions from stroke (when blood fails to get to the brain properly and consequently, brain cells die from oxygen-deprivation: sometimes strokes don't wipe out an entire area but rather just a blood vessel connected to that area), degenerative diseases such as Parkinson's and Alzheimer's and (3) injuries from usually motorcycle accidents
What causes normal forgetting (4 theories)?
1. Encoding failure theory: forgetting is not really forgetting but rather encoding failure (information never entered long-term memory, like the penny) 2. Storage decay theory: biological representation of the memory gradually decays over time and that periodic usage of the information will help to maintain it in storage (we forget because we cannot possibly remember it) 3. Interference theory: other information interferes and make the forgotten information inaccessible 4. Cue-dependent theory: forgetting stems from not gaining access to the desired information but the cues necessary for retrieval are not available or we cannot find it (tip of the tongue)
How do we know how fast neural transmission is (wrong behavior limitations)?
1. It is very difficult to time the exact moment we poke that person's finger. 2. The sensory signal must travel up the arm and the brain. This is the time we want. 3. The interneurons must register the sensory signal and send a signal to the motor neurons to say "ow." 4. The mouth must physically say "ow."
4 theories of emotion:
1. James-Lange theory: (1) physiological arousal and behavior (simultaneously) (2) cognitive appraisal based on emotional and physical response (relies on specific arousal and response patterns) 2. Cannon-Bard theory: 3 responses occur simultaneously but independently (arousal and behavioral responses do not cause emotional feeling nor vice versa) (arousal patterns for different emotions are too physiologically alike to be used to determine which emotion is being experienced) 3. Schachter-Singer two-factor theory: (1) physiological arousal tells us how intense the emotion is (2) cognitive appraisal of the situation identifies the emotion (cognitive appraisal precedes the emotion) 4. "Common-sense": (1) cognitively recognize dangerous situation -> (2) lead to emotional fear and physical arousal -> (3) behavioral component
The motion aftereffect (e.g., the waterfall illusion from class) occurs due to two key features of how neurons fire. What are those two features, and how do they create the motion aftereffect?
1. Neurons have a baseline rate of firing action potentials, even when they are not being activated by neurotransmission from another neuron. 2. After high periods of activity (i.e., high intensity firing of action potentials), neurons become "fatigued" and have a lower rate of baseline firing and generally a lower probability of firing an action potential. (This is technically called "neuronal adaptation;" it might not really be fatigue per se, but an adaptive, useful design feature) - After looking at an image for a long time that has a single predominant motion (i.e., upward movement), your neurons that represent that motion direction become fatigued (or adapted). - When switching to a static, non-moving image, the fatigued neurons representing the motion direction you were watching will temporarily have a lower base rate of firing. - However, the neurons representing the opposite motion (i.e., down) will have their normal base rate of firing. - While at normal rest these "up" and "down" perceptual neurons "cancel" each other out, because the "up" neurons are temporarily fatigued and firing less and the "down" neurons have their normal base rate of firing, and the "down" neurons temporarily "win." - This produces a percept of a static image moving downward.
Emotion
1. Physical component: a state of physiological arousal triggered by the autonomic nervous system (sympathetic nervous system fight-or-flight mode) 2. Behavioral component: outward expression of the emotion, including facial expressions, movements, and gestures (the somatic nervous system: provides the non-verbal, expressive behavior for emotion such as facial-feedback) 3. Cognitive component: appraisal of the situation to determine which emotion we are experiencing and how intensely we are experiencing it
How do we figure what part of the brain does what (4)?
1. Put electrodes in an animal and determine which neurons are responsible for which action. The limitation is how we translate this to humans. 2. Find a person with a major injury and see how the person changes due to his injury. The limitation is that not many people have major injuries. 3. Transcranial magnetic stimulation: a magnetic force that temporarily disturbs brain cells, but it affects a pretty large area and can only study things on the surface 4. Neuroimaging: EEG/ ERP, fMRI
7 types of elaborative rehearsal
1. Self-reference effect: relate information to yourself (e.g. remembering a list of words such as "generous" and apply it to yourself) 2. State-dependent memory: memory that depends upon the relationship of one's physiological state at time of encoding and retrieval (e.g. if under the influence when encoding, then best to be under the influence when retrieving) 3. Mood-dependent memory: retrieval of a particular memory is better when a person's mood at retrieval is the same as it was during encoding 4. Mood-congruence effect: the tendency to recall memories that are congruent with a person's current mood (reason that depressed patients report more sad memories) 5. Mnemonics: a memory aid such as peg-word system (structure: visually associate the items in a list with a jingle that you first memorize: "one is a bun, two is a shoe") 6. Method of loci (most effective): relating information to sequential location and imagery/ story for each locations 7. Context cue, chunking
5 Stages of Sleep
1. Stage 1: 5 minutes 2. Stage 2: 20 minutes (characterized by periodic bursts of rapid activity called sleep spindles) 3. Stage 3: brief, transitional sleep 4. Stage 4: deep sleep (characterized by delta waves, large, slow brain waves) (parasympathetic nervous system dominates but brain is still monitoring environmental information) 5. Return to stage 3 and 2 sleep and then enter REM (rapid eye movement) sleep: paradoxical because while muscles are relaxed, other body systems and the brain are active
Odors are the most effective retrieval cues because of 3 reasons:
1. The neural pathway for odor is different from other senses; it goes directly to the olfactory bulb to the hippocampus to the amygdala. This reduces interference. 2. There may be an evolutionary advantage because odor can tell us much about whether a particular food is poisonous or not. Larsson presented the elderly with smells, and they were most likely to have childhood memories, suggesting a strong connection between smell and memory. 3. It could be an anatomical configuration. Smells are harder to rehearse, and so they are not diluted with out-of-context memories.
Other ways of learning:
1. Understanding what you are trying to learn because it makes things more coherent and limits the set of bad hypothesizes. The memory has more recall cues. 2. Spacing (distributed study) effect: superior long-term memory for spaced study versus massed study (cramming). In an experiment, 5th graders learned words better when they studied a week apart rather than just 2 days. 3. Focus on the material you don't know yet. 4. Testing effect: testing enhances memory by allowing you to practice retrieval, which is what exams require. In an experiment with 4 possibilities (S40T40, S40TW, SWT40, SWTW), S40TW about same accuracy as SWTW
3 overall conclusions:
1. We are not as in charge of ourselves as we think are. Much cognition is beneath our awareness. Examples include epiphenomenalism and the experiments. 2. The brain is a collection of parts, not "one thing." 3. Introspection cannot tell us everything we need to know.
Perception is fairly easy to research because:
1. We can manipulate 1 element of perception easily, and people generally have the same general responses. 2. Animal perceive things similarly to us, and we can put electrodes in animals to examine perception. We can observe which neurons fire when an animal perceives something.
Elizabeth Loftus study
: (1) have people watch a film of a minor fender-bender (2) then have them fill out series of questions (about how fast were the cars going when they smashed/ hit// no question of how fast each other (during time of encoding: wording of the "smash/ hit/ 0" creates a different memory) (3) wait a week, then ask questions, "did you see any broken glass" - "Smashed": 32% said yes (reconstructing the cars) - "Hit": 14% said yes - Control group no question or a neutral question: 12% said yes
3 basic points about memory
:(1) there are different kinds of memory (2) memory is constructive, not a replica of the actual events (3) memory is related to attention
How did Paul Broca and Karl Wernicke discover the Broca's Area and Wernicke's Area?
By analyzing deceased people's brain and relating a person's brain analysis to their behavior while living
Sub-title: The Brain Miscellaneous
Sub-title: The Brain Miscellaneous
Sub-title: Visual Sensation
Sub-title: Visual Sensation
Sub-title: Brain Anatomy
Sub-title: Brain Anatomy
Sub-title: Brain Introduction
Sub-title: Brain Introduction
Sub-title: Brain Recitation
Sub-title: Brain Recitation
Sub-title: Brain Study Questions
Sub-title: Brain Study Questions
Sub-title: Class 1 Study Questions
Sub-title: Class 1 Study Questions
Sub-title: Color Processing
Sub-title: Color Processing
Sub-title: Dualism
Sub-title: Dualism
Sub-title: Experiments
Sub-title: Experiments
Sub-title: Hearing Sensation
Sub-title: Hearing Sensation
Sub-title: Memory
Sub-title: Memory
Sub-title: Nervous and Endocrine System
Sub-title: Nervous and Endocrine System
Sub-title: Perception
Sub-title: Perception
Sub-title: Recitation Notes Research Methods
Sub-title: Recitation Notes Research Methods
Sub-title: Research Methods
Sub-title: Research Methods
Sub-title: Research Statistics
Sub-title: Research Statistics
Sub-title: Sensation (General)
Sub-title: Sensation (General)
Sub-title: Sensation and Perception Questions
Sub-title: Sensation and Perception Questions
If a study shows that students who sleep >8 hours per night have better grades, can we conclude that more sleep causes better grades?
a- No. We can say that more sleep is associated with better grades, but we cannot say that more sleep causes better grades. - Correlation does not imply causation. - Maybe there is a third variable (such as: being responsible in general causes more sleep and causes better studying, but neither sleep nor studying cause each other). - Or maybe the direction is the other way around: perhaps better grades cause more sleeping (e.g., you're already doing fine in class, you can sleep easy).
Sometimes what we think we know, and what is intuitive, may not always be true. Describe a study that could be an example of this sort of surprising result - for example, the "honesty box" study or the one about the daycare late fees. How were the results explained?
a. A daycare center was frustrated that parents were late in picking up their children, so they started to charge a late fee. However, parents tended to be late more often after the fee was implemented. Researchers Gneezy & Rustichini propose that these results occurred because the social pressure to be on time was actually more powerful than the economic consequence. b. The honesty box study showed that people anonymously donated more money for coffee supplies they had used when the money box for donations had pictures of eyes (as opposed to flowers) posted on it. This result calls into question our awareness of the forces that act to control our thinking and behavior.
False memories
an inaccurate memory that feels as real as an accurate memory
Consciousness
an individual's subjective awareness of their inner thinking and feeling and their external environment
Transduction
conversion of physical energy into neural signals that the brain can understand
Retroactive interference
disruptive effect of new learning on the retrieval of old information
Proactive interference
disruptive effect of prior learning on the retrieval of new information
Tip-of-the-tongue phenomenon
failure to recall specific information from memory combined with partial recall and the feeling that recall is imminent
Schemas
frameworks for our knowledge about people, objects, events, and actions that allow us to organize and interpret information about our world
Scaling
how perceptual scales of measurement relate to physical scales of measurement
Significance of false memories
important especially in criminal cases and eyewitness testimonies from children (Sam Stone) and repressed memories
Sensory Adaptation
our sensitivity to unchanging and repetitious stimuli disappear over time because our senses are set to detect changes in the environment
Retrieval
process of bringing information stored in long-term memory to the conscious level in short-term memory
Encoding
process of transferring information from one memory stage to the next
Storage
refers to the process of maintaining information in a particular stage (temporary except in long-term memory
Elaborative rehearsal
rehearsing by relating the new material to information already in long-term memory
Place theory
s- pecific place along the basilar membrane, starting from the oval window, which will respond maximally to a particular frequency. - Brain will know the frequency by knowing the location of peak activity along the basilar membrane. - This is true, especially for high pitches.
How neurons detect motion because we do not have a sensory receptor for motion? We only have sensors that tell us there is a stimulus present in a visual field. How does the receptor circuit work?
• First, we detect a stimulus in the receptive field, the area of space in which if there is a stimulus there, a neuron will respond to it. • There is an extra neuron in the left receptive field so that the neural impulses will be slower on the left. The "M" only responds if it receives input from both "A" and "B." Remember that the "B" signal will be slightly slower, and so the "A" and "B" signal will reach M at the same time. • There are multiple of these kinds of receptor circuits in different orientations because in this case, if the bug is facing the opposite direction, then the receptive circuit won't work. • The limitation is that the neuron can only fire at a certain rate and the neurons can't do many different kinds of tasks.
Ellen Langer Mindfulness Xerox Machine
• In this experiment, Ellen Langer waits in a line to make photocopies. She then tries to cut the line by asking 1 of 3 lines: - Excuse me, I have 5 copies. May I use the Xerox machine? (the no-excuse) - Excuse me, I have 5 copies. May I use the Xerox machine because I have to make copies? (the placebic) - Excuse me, I have 5 copies. I'm in a rush. May I use the Xerox machine? (the sufficient excuse) • Percentage of people who allowed Ellen to cut the line is nearly identical in the placebic and sufficient excuse. However, in the 25-sheet experiment, the percentage of people who allowed Ellen to cut the line is nearly identical in the no-excuse and the placebic excuse. • The conclusion is that when people think you have a reason to do something, they generally let you do it, no matter how bad the reason is. - In this incident, the placebic excuse is self-explanatory. This illustrates mindlessness. People responded to the phrasing of the question rather than the content, although there are limits; for example, saying an elephant was after her did not work.
Pay What You Want
• In this experiment, Gneezy, Nelson, and Brown experimented on people on a rollercoaster. While on the rollercoaster, the riders would get their picture taken. Then, the riders would have the option to buy the picture. The dependent factor was the likelihood of the photo being bought and the independent factors were the price and whether the money would be given to charity. • The results are shown below in a 2 by 2 design, meaning there are 2 independent factors involved. The options were: (1) $12.95 for the picture (2) $12.95 for the picture and half is donated to charity (3) pay what you want for the picture (4) pay what you want for the picture and half is donated to charity. The percentage difference and the monetary difference in the pay what you want category is very interesting. • The conclusion is that people want a positive self-regard. In this case, people don't want to pay too much for the picture. Hence, in the pay what you want but not donated to charity, 8.4% bought the picture. However, if half is donated to charity, then people feel the need to donate more but at the same time, they don't want to pay more. The way out for their positive self-regard is that they don't want the photo anyways.
Wave terminology
• Wavelength refers to the distance in one cycle of a wave, from one crest to the next. As wavelengths decrease from 700nm toward 400nm, the resulting hues go from red through the colors of the spectrum to violet. • Amplitude refers to the amount of energy in a wave, or its brightness and loudness. • Frequency refers to the number of times the waveform cycles in one second and determines pitch in sound.
Big Brother's Eyes and Honesty
• The underlying assumption is that we, as humans, are in charge of ourselves. We do things because we want to do those things. • In this experiment, Bateson, Nettle, and Roberts set up an honesty box in the office. The idea is that employees are offered coffee, and they should put the money in the honesty box based on honor code alone. On some days, Bateson, Nettle, and Roberts would put a picture of a flower upon the box, and on other days, they would put a picture of a pair of eyes upon the box. • The result was that people paid 2.75 times more and followed the "honor code" when a pair of eyes were above the honesty box than was a picture of flowers. • The conclusion is that we, as humans, need approval from other people, such as the pair of eyes. • Of course, there are limitations to this experiment. There was not random sampling
A Fine is a Price
• The underlying assumption that people are rational and predictable. Punishment leads people to do things less, as with operant conditioning. • In this experiment, Gneezy and Rustichini were in a daycare setting. After letting the daycare come about its daily routine, the daycare started imposing a fee for parents who come late. • The result is that once the fee was imposed, parents started to come later and later. Even when the daycare got rid of its fee, the parents were still in the routine of coming later to pick up their children from the daycare. The fee idea backfired; originally, they imposed the fee to stop parents from coming later. • The conclusion is there is a cost to coming late to pick up your children. It's a social cost; "you're the douche who keeps coming late." And the social cost is more severe than the monetary cost. In other words, people are willing to pay to save face.