AP Psych - Chapter 4: Sensation and Perception

What is threshold?

the minimum amount of stimulation necessary to trigger a response

what is difference threshold?

- A difference threshold is the smallest physical difference between two stimuli that can still be recognized as a difference example: your sibling asks you to turn down the volume of the TV. You don't want to lower the volume but want to help your siblings. You think what is the least amount you can lower the volume while still keeping the volume cleary audible? Your ability to make this judgement is your difference threshold. Your sibling may say that you didn't turn the volume down enough or I don't hear a difference. Your sibling is exhibiting their own difference threshold. If you hear a difference, it exceeds your difference threshold but if your sibling hears a difference, it exceeds their difference threshold

what part of the brain must neural messages reach before any sensations such as "hot", "cold", "sweet" be generated?

- neural signals must reach the cerebral cortex

what is learning based inference?

- Helmoholtz pointed out that the important of learning(or nurture) in perception in his theory learning-based inference - in his theory, he emphasized how people use prior learning to interpret new sensory information. Based on this learning, the observer makes inferences-guesses or predictions about what the sensations mean - ex: you infer a birthday party when you see lighted candles on a cake - learning based inference: the view that perception is primarily shaped by learning(or experience) rather tha by innate factors

what is perception?

- a process that makes sensory patterns meaningful. It is perception for example that makes words in a book you are reading meaningful, rather than just a string of visual pattern - to make sensory patterns meaningful, perception draws heavily on memory, motivation, emotion and other psychological processes - perception is a mental process that assigns meaning to incoming sensory patterns, and thus create an interpretation of sensation

what is brightness?

- a psychological sensation caused by the intensity or amplitude of light waves - brightness is determined by how much light reaches the retina - the more bright something is the more neural activity in the retina there is thus the brain senses brightness by the level of neural activity produced in the retina and passed along through the optic pathways

what is placebo effect?

- a response to a placebo(a fake drug), caused by subjects belief that they are taking real drugs - brain's response to placebo is same as pain relieving drugs - placebo's cause the brain to release painkilling endorphins

what is pitch?

- a sensory characteristic of sound produced by the frequency of the sound wave - a sound's frequency determines the highness or lowness of a sound - a quality known as the pitch - high frequencies produce high pitches and low frequencies produce low pitches

what is basilar membrane?

- a thin trip of tissue sensitive to vibrations in the cochlea. The basilar membrane contains hair cells connected to neurons. When a sound wave causes the hair cells to vibrate, the associated neurons become excited. As a result, the sound waves are converted(transduced) into nerve activity

what is signal detection theory?

- according to signal detection theory, sensation depends on the characteristics of the stimulus, the background stimulation and the detector - signal detection theory also explains why thresholds are variable - why for example you notice a certain sound one time and not the next - unlike classical theory of thresholds which states that if a signal was intense enough to exceed absolute threshold, it would be sensed, if below the absolute threshold, it would be missed. The signal detection theory is not a simple present/absent, yes/no experience - one thing that the signal detection theory offers that classical psychophysics(study of stimulation, thresholds, and sensory experience) missed is the variability in human judgement. Signal detection theory recognizes that the observer whose physical and mental status is always in flux, must compare a sensory experience with every-changing expectations and biological conditions - by taking into account the variable conditions that affect detection of a stimulus, signal detection theory provides a more accurate portrayal of sensation than did classical psychophysics - unlike classical psychophysics, signal detection theory takes observer's characteristics into account

what is law of similarity?

- according to the law of similarity, we group together things that have a similar look, sound, feelings, and etc - the gestalt principle that we tend to group similar objects together in our perceptions

what is transduction?

- all sensory communication with the brain flows through neurons in the form of neural signals but neurons however cannot transmit light or sound waves or any other stimulus- sounds, tastes, smells never make it to the brain - it is the job of sensory receptors to covert incoming stimulus to neural messages. This can be done through transduction - the sensory process that converts physical energy such as light or sound waves into the form of neural messages. Once converted, when neural messages reach the cerebral cortex, sensations such as "red", "hot" or "cold" can occur - transduction is the transformation of one energy to another - especially the transformation of stimulus information into nerve signals by sense organs.

what is color?

- also called hue - color is not a property of things in the external world. Rather it is a psychological sensation created in the brain from information obtained by the eyes from the wavelengths of visible light - color is a sensation

What is top-down processing?

- also known as conceptually driven processing - perceptual analysis that emphasizes the perceiver's expectations, concept memories and other cognitive factors, rather than being driven by the characteristics of the stimulus - invokes a perceiver's goals, past experiences, knowledge, expectations, memory, motivations, or cultural background in the interpretation of an object or event

What is bottom-up processing?

- also known as stimulus-driven processing - perceptual analysis that emphasizes characteristics of the stimulus , rather than our concepts and expectations; basic analysis determining the characteristics of the stimulus: is it moving, what color is it, is it loud, and etc

what is the difference between amplitude/frequency/complexity and loudness/pitch/timbre?

- amplitude/frequency/complexity are physical properties of the physical sound wave while loudness/pitch/timbre exist only in the brain, are psychological sensations

what is relative motion?

- as you move, objects at different distances appear to move through your field of vision at a different rate or with a different relative motion - more closer objects such as fences seem to move at a greater speed while more distant objects stay in your field of view longer moving very slowly

why are there two types of photoreceptors?

- because we sometimes function in near-darkness and sometimes in bright light, we have evolved two ways of processing using two distinct receptor cell types - the rods and cones

what are subjective contours?

- boundaries that exist not in the stimulus but only in the subjective experience of your mind - your brain divides images into regions

what are bipolar cells?

- cells in the retina that are vital to vision that don't respond directly to light - bipolar cells have the job of collecting impulses from many photoreceptors(rods and cones) and shuttling them on to the ganglion cells

what are binocular cues?

- certain depth cues, the binocular cues, depend on the use of two eyes - if you hold hold a finger 6 inches away from your eyes, and then move it 1 feet away from your eyes, you feel a change in your eye muscles as you focus at different distances. This feeling serves as one of the main cues for depth perception when looking at objects that are relatively close. The term for this is binocular convergence, suggesting how the lines of vision from each eye converge at different angles on objects at different distances - another binocular cue is retinal disparity, which arises from the difference in perspectives of the two eyes. If we look at your finger with each eye, you will see different parts of your finger. This demonstrates retinal disparity - information taken in by both eyes that aids in depth perception, including binocular convergence and retinal dispaity

what are pheromones?

- chemical signals released organisms to communicate with other members of their species. Pheromones are often used by animals as sexual attractants - ants, termites, and vertebrates such as dogs and cats use sense of smell for communication creating and detecting odorous signals called pheromones

what is interposition?

- closer objects will cut off our vision of more distant objects behind them, a distant cue known as interposition - partially hidden objects are more distant than the objects that hide them

what is closure?

- closure makes you see incomplete figures as wholes by supplying the missing segments, filling in gaps, and making inferences about potentially hidden objects - the gestalt principle that identifies the tendency to fill gaps in figures and to see incomplete figures as complete

What is color blindness?

- color blindness is typically a genetic disorder although sometimes may be result of trauma, that prevents an individual from discriminating certain colors. The most common form is red-green color blindness - the inability to distinguish colors - most people usually just have a color weakness not complete color-blindness, that causes minor issues in distinguishing colors - people with one form of color weakness can't distinguish pale colors such as pink or tan - those who confuses yellow and blue are rare, about one or two people per thousand - most rare is those who see not color at all and see only variations of brightness

What is the trichromatic theory?

- color processing begins in the retina where three different types of cones sense different parts of the visible spectrum - light we sense as red, green and blue. This three-receptor explanation for color vision is known as the trichromatic theory - for some time the trichromatic theory accounted for color vision completely but we now know that the trichromatic theory best explains the initial stages of color vision in the cone cells - trichromatic theory: the idea that colors are sensed by three different types of cones sensitive to light in the red, blue and green wavelengths. Explains the earliest stage of color sensation

What is Fechner's Law?

- fechner's law expresses the relationship between the acute magnitude of the stimulus and its perceived magnitude. - an increase in the physical magnitude of a stimulus progressively produces smaller increases in perceived magnitude. - The magnitude of a stimulus can be estimated by the formula S = k *log*R where S = sensation, R = stimulus and k = a constant that differs for each sensory modality(sight, touch, temperature, etc)

What is frequency?

- frequency is the number of vibrations or cycles the wave completes in a given amount of time usually a second - frequency is usually measured in cycles per second(cps) or hertz(Hz) - frequency determines the pitch, how high or low the pitch is

what are ganglion cells?

- ganglion cells receive information from bipolar cells - bundles of the axons of the ganglion cells make up the optic nerve

what is the law of pragnanze?

- gestalt psychologist suggested the laws of perceptual grouping exemplify a more general principle known as the law of pragnanz(meaningfulness) - this principle states that we perceive the simplest pattern possible- the percept requiring the least mental effort - also known as minimum principle of perception

What is atmospheric pressure?

- haze or fog makes objects in the distance look fuzzy, less distinct, or invisible, creating another learned distance cue called atmospheric perspective

what is laws of perceptual grouping?

- how do we pull together in our minds the separate stimulus elements that seem to belong together? This is a question that Gestalt psychologists addressed - laws of perceptual grouping: the gestalt principles of law of similarity, proximity, continuity, and common fate. These laws suggest how our brain prefer to group stimulus elements together to form a percept(gestalt)

What are super tasters?

- individuals vary in their sensitivity to taste sensations, a function of the density of these papillae on the tongue - those with more taste buds for bitter flavors are super tasters who are more sensitive than regular tasters or extreme non-tasters

what are monocular cues?

- information about depth that relies on the input of just one eye - includes relative size, light shadow, interposition, relative motion and atmospheric perspective

what is amplitude?

- is a measure of the physical strength of the sound wave(shown in its peak-to-valley height) - amplitude is defined in units of sound pressure or energy - amplitude is measured from peak(top) to valley(bottom) on a graph of the wave - amplitude, the intensity of a sound wave determines the psychological sensation loudness: how loud or soft a sound is

what is light and shadow?

- lighter-colored objects seem closer to us, and darker objects seem farther away. Thus light and shadow work together as a distance cue

what is the frequency range of human auditory sensitivity?

- lowest frequency of 20 cps to frequencies as high as 20,000 cps - creatures such as dogs can hear sounds higher than humans while elephants can hear sounds lower than we can

what are cones?

- making the fine distinctions necessary for color vision is the job of the seven million cones that come into play in bright light - each cone is specialized to detect light waves we sense either as blue, red, or green - cones: photoreceptors in the retina that are especially sensitive to colors but not to dim light - the cones concentrate in the very center of the retina, in a small region called the fovea

conceptual question: if a tree falls in the forest and there is no ear to here it, is there a sound?

- no because even though the tree makes a strong vibration in the air, we know that it produces no physical sounds because sound is not a physical phenomenon. Sound is purely a psychological sensation that requires an ear to produce it

does our brain receive the actual stimuli themselves from the outside world?

- no, our sensory impressions of the world involve neural representations of the stimuli - not the actual stimuli themselves - the brain doesn't receive the actual stimulation but rather a neural representation of the stimuli - the brain senses the world indirectly because the sense organs coverts stimulation into the language of the nervous system: neural messages - our brain cannot receive light from sunlight, inhale the fragrance of a rose, rather our brain relies on the secondhand information received from the sensory system

how does the visual system create color?

- objects such as trees, flowers, and etc itself are colorless - color doesn't exist outside the brain because color is a sensation that the brain creates based on the wavelengths of light striking our eyes. Thus color only exists in the mind of the viewer - a psychological property of our sensory experience - color is created when the wavelength in a beam of light is recoded by the photoreceptors in the form of neural impulses and sent to specialized areas of the brain for sensory processing

what is context and expectations?

- once you identify a context, you form expectations about what persons, objects, and events you are likely to experience - ex: it is difficult to recognize people you know in situations where you didn't expect them to be, such as in a different city, or new social group - it is harder to recognize people outside their usual setting

what is a figure and what is a ground?

- one basic perceptual processes identified by the Gestalt psychology divides our perceptual experience into figure and ground figure: - a figure is simply a pattern, or gestalt, that grabs our attention - the part of a pattern that commands attention - figure stands out against the ground ground: - the part of the pattern that does not command attention; the background

What is sensory adaptation?

- one important function of stimulus detectors such as the sense organs is to announce changes in the external world such as a flash of light, a splash of water, a clap of thunder and etc. Sensory organ's receptors are specialized at gathering information about new and changing events - it is very important for our sensory information to adapt to stimulus. This can be seen through sensory adaptation - sensory adaptation is the diminishing responsiveness of sensory systems to prolonged stimulation like for example when you adapt to the feel of swimming in cold water. - Stimulation persisting for long periods without change usually shift to the background of our awareness due to sensory adaptation - sensory adaptation: loss of responsiveness in receptor cells after stimulation has remained unchanged for a while; ex: a swimmer gets adapted to the temperature of the water

what are feature detectors?

- our brain have specialized groups of cells dedicated to the detection of specific stimulus features such as length, slant, color, and boundary - these cells are called feature detectors - feature detectors are cells in the cortex that specialize in extracting certain features of a stimulus - one thing we do know is that in order to bind these pieces into a meaningful percept, the brain synchronizes the firing patterns in different groups of neurons that have each detected different features of an object

put this somewhere useful when found

- our mind lacks contact with the outside world so no matter what we do, information we get about external events must always be filtered through our sense organs and the combine with our unique mix of memories, emotions, motives and expectations

what is the importance of pain?

- pain is a part of your body's adaptive mechanism that makes you respond to conditions that threaten damage to your body - pain can arise from intense stimulation of various kinds such as very loud sound, heavy pressure, extremely bright light and etc - people born without a limb or have a limb amputated feel painful sensations coming from missing limb known as phantom limb - pain warns us of potential harm, help us survive in hostile environments, and get treatment for sickness and injury

what is percept?

- perception brings meaning to sensation, so perception produces an interpretation of the world, not a perfect representation of it - task of perception is to extract sensory input from the environment and organize it into stable, meaningful precepts - percepts are what we perceive - percept: the meaningful product of perception - often an image that has been associated with concepts, memory of events, emotions and motives

what is the binding problem?

- refers to the process used by the brain to combine(bind) the results of many sensory operations into a single percept. No one knows exactly how the brain does this. Thus the binding problem is one of the major unsolved mysteries in psychology

what are afterimages?

- sensations that linger after the stimulus is removed. Most visual afterimages are negative afterimages which appear in reversed color

what is skin senses?

- sensory system for processing touch, warmth, cold, texture, and pain - the skin senses are connected to the somatosensory cortex located in the brain's parietal lobes - the skin's sensitivity to stimulation varies over the body, depending on the number of receptors in each area - in general, the sensitivity is the greatest on our faces, tongues, and hands

what is an illusion?

- sometimes our perceptions can be wildly inaccurate because we misinterpret an image. This is known as illusions - illusions: you have experienced an illusion when you have a demonstrably incorrect perception of a stimulus pattern - when your mind deceives you by interpreting a stimulus pattern in a manner that is demonstrably incorrect, you are experiencing an illusion - illusions are more likely when stimulus is unclear, information is missing, elements are combined in unusual ways, or familiar patterns are not apparent

What are ambiguous figures?

- stimulus patterns that can be interpreted in two or more distinct ways - images that are capable of more than one interpretation. There is no right way to see an ambiguous figure - after we see all the ways to interpret these ambiguous figures, our perception will cycle back and forth between these images. This is due to shifting of perceptual control between the left and right hemisphere

what are the taste receptor cells? How is taste sent to the brain?

- taste receptor cells are gathered in taste buds, located on the top and side of the tongue where they can easily sample the molecules in our food and drinks - these taste bud receptors clust in small mucous-membrane projections called papillae - a specialized nerve hotline carries nothing but taste messages to the brain. There taste is realized in a specialized region of the parietal lobe somatosensory cortex which lies under the patch of cortex that receives touch stimulation from the face

what are the rods?

- the 125 million tiny rods "see in the dark" - that is they detect low intensities of light at night, though they cannot make the fine distinctions that give rise to our sensations of color. - EX: rod cells enable you to find a seat in a darkened movie theater - rods photoreceptors in the retina that are especially sensitive to dim light but not to colors

what is perceptual constancy?

- the ability to recognize the same object as remain constant under different conditions, such as changes in illumination, distance or location - example: a opened door: your sensory image of it is distorted when you are not looking at it straight on but your brain automatically corrects the sensory distortion so that you perceive the door as rectangular - color constancy: enables us to see same colors at different distances, locations, angles - size constancy: allows us to perceive objects as same size at different distances, locations, angles - shape constancy: ability for us to perceive same shape at different distances, locations, angles

what is timbre?

- the bark of a dog, a train whistle, the click of a spoon in a cup - all sound distinctively different nit just because they have different pitches or loudness but also because they are peculiar mixtures of tones - most natural sound waves are mixtures rather than pure tones. The complexity of a sound wave is known as timbre - timbre is the property that enables you to recognize your friends voice or distinguish between songs - timbre: the quality of a sound wave that derives from the wave's complexity(combination of pure tones)

what is the retina?

- the eye can transduce the characteristics of light into neural signals that the brain can process. This transduction happens in the retina, the light-sensitive layer of cells at the back of the eye - retina is the thin, light-sensitive layer at the back of the eyeball. The retina contains millions of photoreceptors and other nerve cells retina includes: - photoreceptors: cones and rods - fovea - bipolar cells - ganglion cells - optical nerve

What is the gate control theory?

- the gate control theory explains why pain can sometimes be blocked by analgesic drugs, competing stimuli such as acupuncture, and even by mere expectation of treatment effects - pain depends on the relative amount of traffic in two different sensory pathways which carry information from the sense organs to the brain: - one of these routes consisting of neurons with a fatty myelin covering on their axons, handles messages quickly; these fast fibers deliver most sensory information to the brain - slow fibers, without the myelin covering on their axons, send messages more slowly; intense stimuli such as that caused by tissue injury send strong signals on the slow fibers - the gate-control theory hypothesized that fast fibers can block pain messages in the slow fibers. The fast fiber close a spindle gate, preventing the slow fiber's messages from reaching the brain - the amount of pain you experience from a wound results from the combination of information coming by the fast fibers and slow fibers - the "gate" in this theory operates in region of brain stem called periaqueductal gray(PAG); pain blocking opiates and endorphins act on PAG. Pain signals passing through gate are routed to the anterior cingulate cortex in the frontal lobes

what is law of continuity?

- the gestalt law of continuity says that we prefer smoothly connected and continuous figures over disjointed, disconnected ones

what is law of common fate?

- the gestalt principle that we tend to group similar objects together that share a common motion or destination - ex: when a group of geese for example are moving together, you perceive them as a single gestalt

What is Gestalt psychology?

- the gestalt theory emphasizes how we organize incoming stimulation into meaningful perceptual patterns - because of the way our brain are innately structured - gestalt theory emphasizes nature - argued that the brain is innately wired to perceive not just stimuli by patterns in stimulation. They called such a pattern a gestalt - a german word for perceptual pattern or configuration - the brain forms a perceptual whole that is more than the mere sum of its sensory parts - gestalt psychology: from a german word that means whole or form or configuration, the gestalt psychologist believed that much of perception is shaped by innate factors built into the brain - ex: gestalt psychologist stated that we perceive a square as a single figure, not four individual lines; when you hear a song, your brain doesn't focus on individual notes but rather extracts the melody, which is your perception of the overall patterns - gestalt psychologist believed we always organize sensory information into meaningful patterns

What is kinesthetic sense?

- the kinesthetic snes, the other sense of body position and movement, keeps track of body parts relative to each other. Your kinesthetic sense makes you aware of crossing your legs, and tells you which hand is closer to the telephone when it rings for example - kinesthesis provides constant sensory feedback about what the muscles in your body are doing during motor activities - receptors for kinesthesis reside in the joints, muscles, and tendons. These receptors as well as those for the vestibular sense connect to processing regions in the brain's parietal lobes-which help us make a sensory map of the spatial relationship among objects and events. This process happens automatically, outside of conscious awareness except when we are learning the movement for a new physical skill such as playing a new instrument

What is the electromagnetic spectrum?

- the light we can see occupies a tiny segment of the electromagnetic spectrum. - the entire range of electromagnetic energy that includes radio waves, x rays, microwaves, and visible light

what is loudness?

- the loudness of a sound is determined by its physical strength or amplitude - more intense sound waves such as a shout produce louder sounds whereas we experience sound waves with small amplitudes such as a whisper as soft. Thus amplitude refers to physical sound wave and loudness is a psychological sensation - sound intensity(amplitude) is measured in decibels(dB)

What is the opponent process theory?

- the opponent-process theory better explains some cases of color blindness as well as negative afterimages both of which involve opponent(complementary) colors - according to this theory, from the bipolar cells onward the visual system processes colors in either or complementary pairs such as red or green or as yellow or blue. Also in all subsequent layers of the visual cortex, the sensation of a certain color such as red, inhibits the sensation of its complement, green - opponent process theory explains what happens in the bipolar cells and beyond - opponent process theory: the idea that cells in the visual system process colors in complementary pairs

what is the optic nerve?

- the optic nerve transports visual information from the eye to the brain - bundles of neurons of ganglion cells that carries visual information from the retina to the brain

what is the cochlea?

- the primary organ of hearing; a coiled tube in the inner ear, where sound waves are transduced into nerve messages

what is sensation?

- the process of stimulation of a sensory receptor produces neural impulses that the brain interprets as a sound, a visual image, an odor, a taste, a pain, or other sensory images. Sensation represents the first series of steps in processing of incoming information - sensation is the process by which a sensory receptor such as the eyes or ears, creates a patter of neural messages that represent the stimulus in the brain, giving rise to our initial experience of the stimulus - it is important to note that sensation involves changing stimulation(such as a pinprick, a sound, or a flash of light) into a form the brain can understand(neural signals)

What is olfaction?what are the steps?

- the sense of smell - first odors interact with receptor proteins associated with specialized hairs in the nose. The stimulated nerve cells associated with these hairs convey information about the stimulus to the brain's olfactory bulbs where sensation of smell are realized. The olfactory bulbs can be found on the underside of the brain just below the frontal lobes - unlike all the other senses, smell signals are not relayed through the thalamus, suggesting that smell evolved earlier than the other senses - olfaction can be connected to memory; certain smells remind people of certain memories

what is gustation?

- the sense of taste - has four main qualities: sweet, sour, bitter or salty- but recently, scientists have identified a fifth taste quality called umami, which is the flavor associated with MSG - taste and smell are both chemistry based and the sense of taste and smell have a cooperative working relationship. Many flavors you taste really comes from odors you smell

what is weber's law?

- the size of the JND is proportional to the intensity of stimulus - as weber's law - weber's law: this concept says that the size of a JND is proportional to the intensity of the stimulus; the JND is large when the stimulus intensity is high and is small when the stimulus intensity is low EX: if the TV volume is high, you will need to turn the volume down a lot to make the difference noticeably so the JND is bigger. But if the TV volume is low, you don't we need to lower the volume as much so the JND is lower

What is a just noticeable difference (JND)?

- the smallest change in stimuli that is still recognizable - JND is the same thing as difference threshold and psychologist use the terms interchangeably - the JND is always large when the stimulus intensity is high and small when the stimulus intensity is low

what is the fovea?

- the tiny area of sharpest vision in the retina - the cones concentrate in the very center of the retina, in a small region called the fovea, which gives us our sharpest vision - we use the fovea to scan whatever interests us visually such as a face, a picture, a flower

What is the vestibular sense?

- the vestibular sense is the body position sense that orients us with respect to gravity. It tells us how our bodies especially are heads are postured, whether straight, leaning, reclining, or upside down - the vestibular sense also tells us when we are moving or how our motion is changing - the receptors for this information are tiny hairs in the semicircular canals of the inner ear. These hairs respond to our movements by detecting corresponding movements in the fluid of the semicircular canals - disorders of the vestibular sense can cause extreme dizziness and disorientation - vestibular sense is closely associated with the inner ear and in fact is carries to the brain on a branch of the auditory nerve

what two systems control the physical mechanisms that keep track of body position, movement, and balance?

- the vestibular senses and kinesthetic senses

What is a photoreceptor?

- the work performed in the retina is performed by light-sensitive cells known as photoreceptors which consists of two different types of specialized neurons - the rods and cones - which absorb light energy and respond by creating neural impulses - photoreceptors: light-sensitive cells(neurons) in the retina that convert light energy to neural impulses. The photoreceptors are as far as light gets into the visual system

what is the blind spot?

- there is a small area of the retina in each eye where everyone is blind because this part of the retina has no photoreceptors - this blind spot is located at the point where the optic nerve exists each eye, and the result is a gap in the visual field - any stimulus that falls on the bind spot area cannot be seen - if vision is normal, you don't experience blindness due to the blind spots because what one eye misses, the other eye and brain fills in the spot with information that matches the background

What do all senses have in common?

- they all transduce physical stimuli into neural activity and each is more sensitive to change than to constant stimulation, and each of the senses are distinguished from one another by the type of information it extracts and by the specialized regions of the brain devoted to it - all senses only use a fraction of the available stimulation and are especially sensitive to changes in stimulation - all senses signals for all senses except smell are relayed through the thalamus

what is steven's power law?

- this law addresses some issues with Fechner's law and why it cannot account for some changes in stimulus detections. - steven's power law works for a variety of additional stimuli, namely pain and temperature - Steven's power law is written as S = kI^a where S = sensation, k = a constant, I = stimulus intensity, and a = a power exponent that depends on the sese we are measuring - a law of magnitude estimation that is more accurate than Fechner's law and covers a wider variety of stimuli.

Why is touch important?

- touch plays a central role in human relationships - through touch, we communicate our desires to give or receive comfort, support, love and passion - touch also serves as primary stimulus for sex arousal and is essential for healthy mental and physical development - lack of touch stimulation can stunt mental and motor development

what are the steps of transduction?

- transduction begins with the detection by a sensory neuron of the physical stimulus. When the appropriate stimulus reaches a sense organ, it activates specialized neurons called receptors which respond by converting their excitation into a nerve signal. This neural impulse generated carries a code of the stimulus that can be processed by the brain. - the neural impulse generated travels from the receptor cells along a sensory pathway by way of the thalamus to specialized sensory processing areas in the brain - when the neural impulse arrives at the brain, the brain extracts information about the basic qualities of the stimulus such as intensity, pitch, direction - NOTE: the stimulus itself terminates in the receptor. The only thing that continues on into the nervous system is information carried by the neural impulse

what is perceptual set?

- under the influence of perceptual set, we have a readiness to notice and respond to certain stimulus cues such as a runner for the start signal - in general, perceptual set involves a focused alertness for a particular stimulus in a given context; ex: a mother is set to hear the cries of her child - often a perceptual set leads you to transform an ambiguous stimulus into the one you were expecting - perceptual set: readiness to detect a particular stimulus in a give context - as when a person who is afraid interprets as unfamiliar sound in the night as a threat

What is the visible light spectrum?

- visible light is the special form of energy that our eyes can detect - the tiny part of the electromagnetic spectrum to which our eyes are sensitive. The visible spectrum of other creatures may differ from our own - within the visible light spectrum, waves of different lengths give rise to different colors thus it is the wavelength of light from which our eyes extract the information used by the brain to construct color - travels at nearly 670 million MPH

how are senses similar and different from one another?

- vision, hearing, smell, taste, touch, pain, body position in certain ways are the same. They all transduce stimulus energy into neural impulses. They are all more sensitive to change than to constant stimulation and they all provide information about the outside world - the senses are different from one another because they all with an exception of pain, taps a different form of stimulus energy and each sends the information it extracts to a different part of the brain - senses all operate in much the same way, but each extracts different information and sends it to its own specialized processing region of the brain - each sense organ has a different design and each sends neural messages to its own specialized region in the brain which is why different sensations occur because different areas of the brain become activated

how can we deal with pain?

- we can take analgesic drugs such as aspirin, ibuprofen, as well as narcotics like morphine - many people learn to control pain by psychological techniques such as hypnosis, deep relaxation, and thought - distraction procedures - people can also take placebos

how does the information given to the brain from the eyes become a visual image?

- we look with our eyes but we see with the brain. To do so, we use a special processing area in the brain to create visual images from the information imported through the optic nerve - in the visual cortex, the brain begins working its magic by transforming the incoming neural impulse into visual sensations of color, form, boundary and movement - the visual cortex also takes the two-dimensional patterns from each eye and assemble them into a three-dimensional wold of depth. With further processing, the cortex combines these visual sensations with memories, motives, emotions and sensations of body position and touch to create a representation of the visual world

what is absolute threshold?

- what is the weakest stimulus that an organism can detect? How dim can a light be and still be visible? How soft can music be but still heard? These questions refer to the absolute thresholds for different types of stimulation - absolute threshold is the minimum amount of physical energy needed to produce a sensory experience - the absolute threshold varies from person to person. For example you may be able to point out a faint star but your friend may not be able to see it - absolute threshold: the amount of stimulation necessary for a stimulus to be detected. - in laboratory, a psychologist would define the absolute threshold as the presence or absence of a stimulus is detected correctly 50% of the time over many trials - absolute threshold varies continually with our mental awareness and physical condition

what characteristic of the eyes make the eyes different from other sense organs?

- what makes the eye different from other sense organs - lies in its ability to extract the information from light waves, which are simply a form of electromagnetic energy

how is attention a key component of sensation and perception?

- without attention, all sensation in the world will not mean anything - sensation and perception without attention are just light and noises - in order for sensation and perception to have any value, there must be attention as well

what are some functions of our senses?

- your senses warn you of danger - our senses have other adaptive functions: they aid our survival by directing use to certain stimuli such as tasty food. - our senses also help us locate mates, seek shelter, and recognize pleasure in music, art, athletics, food and sex

What is the law of proximity?

-the law of proximity states that we group things together that are near each other

how is sound waves transduced into neural impulses and sent to the brain?

1) airborne sound waves must be relayed to the inner ear. In this initial transformation, vibrating waves of air enter the outer ear(also called the pinna) and strike the eardrum or tympanic membrane. This tightly stretched sheet of tissue transmits the vibrations to three tiny bones: the hammer, anvil, and stirrup. These bones immediately pass the vibrations on to the primary organ of hearing, the cochlea, located in the inner ear 2) the cochlea focuses the vibrations on the basilar membrane. Here in the cochlea, the formerly airborne sound wave become "seaborne" because the coiled tube of the cochlea is filled with fluid. s the bony stirrup vibrates against the oval window at the base of the cochlea, the vibrations set the fluid into wave motion, working on the same principle as a submarine sending a sonar ping through the water. In turn, the fluid wave spreads through the cochlea, causing a sympathetic vibration in the basilar membrane, a thin strip of tissue running through the cochlea 3) The basilar membrane converts the vibrations into neural messages. The swaying of tiny hair cells on the vibrating basilar membrane stimulates sensory nerve endings connected to the hair cells. The excited neurons, then, transform the mechanical vibrations of the basilar membrane into neural activity 4) finally, the neural messages travel to the auditory cortex in the brain. Neural signals leave the cochlea in a bundle of neurons called the auditory nerve. The neurons from the two ears meet in the brain stem, which passes the auditory information to both sides of the brain. Ultimately, the signals arrive in the auditory cortex for higher-order processing - the auditory system is like a sensory relay team. Sound waves are first funneled in by the outer ear, then handed off from the tissue of the eardrum to bones in the middle ear. Mechanical vibrations of these bones are then passed to the cochlea and basilar membrane where they finally become neural signals, which are in turn, passed along the brain. Through these steps, vibrations are transformed into sounds of music, doorbells, shouts and etc

what is conduction deafness?

1) conduction deafness - in conduction deafness, the ways in which sound waves are converted to nerve energy have been interfered with or interrupted. Specifically, it is the conduction of the vibrations that has been affected - in most cases, damage has occured to any of the structures of the middle ear either by sound that has been too loud or by some sort of trauma - conduction deafness: inability to hear resulting from damage to structures of the middle or inner ear

describe the transduction of light through the retina?

1) incoming light passes through the ganglion cells and bipolar cells before striking the photoreceptors at the back of the eye ball 2) once stimulated, the rods and cones transmit information to the bipolar cells 3) the bipolar cell then transmits neural impulses to the ganglion cells 4) impulses then travel from the ganglia to the brain through axons that make up the optical nerve

what is relative size?

if tow objects that are assumed to be the same size cast different-sized images on the retina, observers usually judge them to lie at different distances. So a pilot flying low can learn to use the relative size of familiar objects on the group as a cue for depth and distance

what color do short wavelengths construct?

blue

what are the two main physical properties of sound waves?

frequency and amplitude

what color do medium wavelengths construct?

green

What are gustatory cells?

gustatory cells are just taste buds

what is nerve deafness?

nerve deafness: - in nerve deafness, there is a problem with how the impulses from the oval window are sent to the brain; in other words, damage has occured to the auditory nerve or one of the higher auditory processing centers. Most people born deaf have this type - an inability to hear, li ked to a defict in the body's ability to transmit pulses from the cochlea to the brain, usually involving the auditory nerve or higher auditory processing centers

do objects such as tomatoes, flowers, plants, trees and other objects have color?

no, these objects such as flowers or tomatos itself, has no color or hue, they are colorless

does heightened taste sensitivity stay constant throughout one's life?

no. As an infant, you have heightened taste sensitivity which is why they are picky. As you get older, the taste sensitivity decreases which is also why elder people complain that food has lost its taste

what are the three psychological sensory qualities of sounds?

pitch, loudness, and timbre

what color do long wavelengths construct?

red

what are the two types of photoreceptors of the retina?

rods and cones

what is the stimulus, sense organ, receptor and sensations for skin senses?

stimuli: external contact sense organ: skin receptor: nerve endings in skin sensations: touch, warmth, cold

what is the stimulus, sense organ, receptor and sensations for kinesthetic and vestibular senses?

stimulus: body position, movement, and balance sense organ: semicircular canals, skeletal muscles, joints, tendons receptor: hair cells in semicircular canals;neurons connected to skeletal muscles, joints, and tendons sensation: position of body parts in space

what is the stimulus, sense organ, receptor and sensations for vision?

stimulus: light waves sense organ: eyes receptor: rods and cones of retina sensations: color, brightness, patterns, motion, textures

what is the stimulus, sense organ, receptor and sensations for pain?

stimulus: many intense or extreme stimuli: temperature, chemicals, mechanical stimuli, etc sense organ: net of pain fibers all over the body receptor: specialized pain receptors, overactive or abnormal neurons sensations: acute pain, chronic pain

what is the stimulus, sense organ, receptor and sensations for taste?

stimulus: soluble substances sense organs: tongue receptor: taste buds of tongue sensation: flavors(sweet, sour, salty, bitter)

what is the stimulus, sense organ, receptor and sensations for hearing?

stimulus: sound waves sense organ: ear receptor: hair cells of the basilar membrane sensations: pitch, loudness, timbre

what is the stimulus, sense organ, receptor and sensations for smell?

stimulus: volatile substances sense organ: nose receptor: hair cells of olfactory epithelium sensations: odors(musky, flowery, burnt, minty, etc)

why is the taste system the most resistant to permanent damage then all of the other senses?

this is because taste buds(gustatory cell) can be damaged very easily by alcohol, smoke, hot food, acids and etc so the gustatory cells(taste buds) are constantly replaced. Due to this, taste system is the most resistant to pain

how does the auditory system produce sensations of pitch?

two auditory processes share the task: 1) when a sound wave pases through the inner ear, the basilar membrane vibrates. Different frequencies activate different locations of the basilar membrane. Thus, the pitch one hears depends in part, on which region of the basilar membrane receive the greatest stimulation. This explanation of pitch perception is known as place theory, which says that different places on the basilar membrane send neural codes for different pitches to the auditory cortex of the brain, thus perceiving different pitch sensations. The place theory accounts for our ability to hear high tones - above about 1000 Hz(cycles per second) 2) neurons on the basilar membrane respond with different firing rates for different sound wave frequencies. And so, the rate of firing provides another code fro pitch perception in the brain. This frequency theory explains how the basilar membrane deals with frequencies below about 5000 Hz(between 1000 and 5000 Hz) - note: there is an overlap between the place theory and frequency theory especially within range of 1000 - 5000 Hz because this is the range of human speech, and our hearing has evolved in two ways to make sure that we are especially sensitive to sounds in this range - hearing is based on both frequency and place