Chapter 6: Sensation and Perception 2016In a silent, cushioned, inner world, your brain floats in utter darkness… HOW does the world out there get in?!?sensation: perception:

-prosopagnosia-bottom up, top down

Sensing: Basic Principles:transduction, psychophysics, absolute thresholds, versus signal detection, subliminal stimulation, research says: priming, masking stimulus, difference threshold – Just Noticeable Difference (JND), Weber’s Law, sensory adaptation, perceptual sets: schemas, context effects, motivation and emotion

Vision – our #1! light energy, spectrum, wavelength, amplitude – hue, intensity, brightness (sound: loud, high or low) -transduction: the eye -- all parts (f6.13, 6.15, 6.17, pgs. 240-242), plus accommodation, acuity, near versus farsightedness, LASIK surgery -the retina: all parts -- rods and cones, bipolar cells, ganglion cells, optic nerve, blind spot, fovea, plus order / route of transduction, color / detail / darkness issue -color processing: Young-Helmholtz trichromatic theory, additive vs. subtractive color mixing, colorblindness, afterimages, then opponent-process theory in thalamus -feature detection: feature detectors, association areas / supercell clusters, parallel processing; the power / effort of vision, “grandmother cells”, blindsight (“the zombie within”), synchrony

Perceptual organization (“top-down”): gestalt, Necker cube, figure and ground, illusory contours

Grouping: proximity, similarity, continuity, closure

Depth perception: visual cliff, maturation and cues -- -binocular cues: retinal disparity, convergence-monocular cues: relative height, relative motion, relative size, interposition, linear perspective, light and shadow, relative clarity, texture gradient

Motion perception: stroboscopic movement, phi phenomenon

Perceptual constancy: color/brightness constancy, color constancy, brightness/lightness, relative luminance, shape and size, size-distance relationship – moon illusion, Muller-Lyer illusion, Ponzo illusion, Ames room

Perceptual interpretation: Immanuel Kant versus John Locke; sensory deprivation and restored vision, critical period: research says -- (human cataracts, kittens experiment)

Perceptual adaptation: inversion

Audition – range; sound waves, frequency / pitch, amplitude / loudness; decibels -the ear: all parts; transduction – all parts and issues (f6.37, pg. 258), plus brain route

-hearing loss: conduction versus sensorineural hearing loss, noise, cochlear implant -perceiving loudness, perceiving pitch: place theory, frequency theory (AKA temporal theory), volley principle -location: stereophonic hearing, sound shadow, JND

Touch – importance! -transduction: “at least” four distinct skin senses – pressure, warmth, cold, pain –

nerve endings, pressure only has identifiable receptors…-combinations: stroke pressure-pressure: tickle; gentle pain: itch; cold and pressure: wetness; cold and

warmth: hot!-the brain and PAIN – nociceptors, gate-control theory, phantom limb sensations, tinnitus, memory and

pain, social suggestion, pain control, placebos, distraction, hypnosis: hypnotic induction, theories – social influence, dissociation, the hidden observer, posthypnotic suggestions, selective attention

Gustation -- transduction: 5 receptors – sweet, sour, salty, bitter, umami / meaty; others mixtures-aging’s effect, replacement, locations of receptors, localization; universals and learned likes/dislikes, expectation

Olfaction – no crossover; all transduction terms, olfactory membrane / epithelium, receptors; combinations; link to memory, brain route; anosmia

Body Position and Movement: kinesthesia, the vestibular sense, inner-ear transduction – semi-circular canals, cerebellum,

Sensory Interaction: the McGurk effect, embodied cognition, synesthesia

ESP – Perception Without Sensation?-ESP, parapsychologists, telepathy, clairvoyance, precognition, psychokinesis

research says:

Chapter 6: Sensation and Perception 2016 (with spaces)In a silent, cushioned, inner world, your brain floats in utter darkness… HOW does the world out there get in?!?sensation:

perception:

-prosopagnosia

-bottom up, top down

Sensing: Basic Principles:transduction, psychophysics, absolute thresholds, versus signal detection, subliminal stimulation, research says:

priming, masking stimulus, difference threshold – Just Noticeable Difference (JND), Weber’s Law,

sensory adaptation, perceptual sets: schemas, context effects, motivation and emotion

Vision – our #1! light energy, spectrum, wavelength, amplitude – hue, intensity, brightness (sound: loud, high or low)

-transduction: the eye -- all parts (f6.13, 6.15, 6.17, pgs. 240-242), plus accommodation, acuity, near versus farsightedness, LASIK surgery

-the retina: all parts -- rods and cones, bipolar cells, ganglion cells, optic nerve, blind spot, fovea, plus order / route of transduction, color / detail / darkness issue

-color processing: Young-Helmholtz trichromatic theory, additive vs. subtractive color mixing, colorblindness, afterimages, then opponent-process theory in thalamus

-feature detection: feature detectors, association areas / supercell clusters, parallel processing; the power / effort of vision, “grandmother cells”, blindsight (“the zombie within”), synchrony

Perceptual organization (“top-down”): gestalt, Necker cube, figure and ground, illusory contours

Grouping: proximity, similarity, continuity, closure

Depth perception: visual cliff, maturation and cues –

-binocular cues: retinal disparity, convergence

-monocular cues: relative height, relative motion, relative size, interposition, linear perspective, light and shadow, relative clarity, texture gradient

Motion perception: stroboscopic movement, the phi phenomenon

Perceptual constancy: color/brightness constancy, color constancy, brightness/lightness, relative luminance, shape and size, size-distance relationship – moon illusion, Muller-Lyer illusion, Ponzo illusion, Ames room

Perceptual interpretation: Immanuel Kant versus John Locke; sensory deprivation and restored vision, critical period: research says -- (human cataracts, kittens experiment)

Perceptual adaptation: inversion

Audition – range; sound waves, frequency / pitch, amplitude / loudness; decibels

-the ear: all parts; transduction – all parts and issues (f6.37, pg. 258), plus brain route

-hearing loss: conduction versus sensorineural hearing loss, noise, cochlear implant

-perceiving loudness, perceiving pitch: place theory, frequency theory (AKA temporal theory), volley principle -location: stereophonic hearing, sound shadow, JND

Touch – importance! -transduction: “at least” four distinct skin senses – pressure, warmth, cold, pain – nerve endings, pressure only has identifiable receptors…

-combinations: stroke pressure-pressure: tickle; gentle pain: itch; cold and pressure: wetness; cold and warmth: hot!

-the brain and PAIN – nociceptors, gate-control theory, phantom limb sensations, tinnitus, memory and pain, social suggestion, pain control, placebos, distraction,

hypnosis: hypnotic induction, theories – social influence, dissociation, the hidden observer, posthypnotic suggestions, selective attention

Gustation -- transduction: 5 receptors – sweet, sour, salty, bitter, umami / meaty; others mixtures-aging’s effect, replacement, locations of receptors, localization; universals and learned likes/dislikes, expectation

Olfaction – no crossover; all transduction terms, olfactory membrane / epithelium, receptors; combinations; link to memory, brain route; anosmia

Body Position and Movement: kinesthesia, the vestibular sense, inner-ear transduction – semi-circular canals, cerebellum,

Sensory Interaction: the McGurk effect, embodied cognition, synesthesia

ESP – Perception Without Sensation?-ESP, parapsychologists, telepathy, clairvoyance, precognition, psychokinesis

research says:

Chapter 5: Sensations – complete chapter notes

Sensing the World: Some Basic Principles Sensory systems enable organisms to obtain needed information. [Frog feeding on flying insects: has eyes

with receptor cells that fire only in response to small, dark, moving objects.]Thresholds Our sense are open just a crack, allowing us restricted awareness of this vast sea of energy. Psychophysics - study of relationships between the physical characteristics of stimuli, such as their intensity,

and our psychological experience of them. Absolute Thresholds To some kinds of stimuli we are very sensitive. Standing atop a mountain on a dark clear night, we can with normal senses, see a candle flame on another

mountain miles away, and can smell a single drop of perfume in a three room apartment. The awareness of these faint stimuli shows our absolute threshold- minimum stimulation needed to detect a

particular stimulus[light, sound, pressure, taste, odor] 50% of the time. Absolute Threshold tested for sounds, hearing specialist exposes each of your ears to varying sound levels.

For each pitch, hearing test defines where half the time you correctly detect the sound and have the time you don’t. \

Signal Detection Signal Detection - a theory predicting how and when we detect the presence of a faint stimulus [“signal”]

amid background stimulation [“noise”]. Assumes that there is no single absolute threshold and that detection depends party on a persons experience, expectations, motivation, and level of fatigue.

Exhausted parents of a newborn notice the faintest whimper, but fail to notice louder unimportant sounds. Subliminal Stimulation Controversy over false report that movie audiences were being influenced buy flashed messages to “drink

coca-cola and eat popcorn” More controversy-advertisers were said to manipulate consumers by unnoticeably printing the word sex on

crackers and be putting in erotic images in liquor ads. Unconsciously we can sense subliminal [below ones absolute threshold for conscious awareness] stimuli,

and that, without our awareness, these stimuli have extraordinary suggestive powers. One experiment subliminal flashed either emotionally positive scenes or negative sense an instant before

participants viewed slides of people. People looked better after seeing a positive scene. We can process information without being aware of it. An imperceptibly brief stimulus evidently triggers a

weak response that evokes a feeling, though not a conscious awareness of the stimulus. What the conscious mind cant recognize, the heart may know. This subliminal priming phenomenon joins

much other evidence in pointing to the powers, as well as the perils, of intuition. Can advertisers really manipulate us with ‘hidden persuasion’? No-affect like a placebo an effect of one’s

belief in them. “Subliminal procedures offer little or nothing of value to the marketing preactitioner”Difference Threshold To function effectively, we need absolute thresholds low enough to allow us to detect important sights,

sounds, tastes, etc. Need to detect small differences among stimuli too. [Parents detecting the sound of heir own kid’s voice and other kid’s voices.]

The difference threshold –‘just noticeable difference’- minimum difference a person can detect between any two stimuli half the time.

Difference threshold increases with the magnitude of the stimulus. Ernst Weber noted that regardless of their magnitude two stimuli must differ y a constant proportion for

their difference to be perceptible. This principle-that the difference threshold is not a constant amount but some constant proportion of the

stimulus-Weber’s law.

If the price of a 50 cent candy goes up by 5 cents, shoppers might notice the change. It might take $5000 to a $40000 Mercedes to cause recognition in the raise. Both are raised by 10%.

Weber’s principle: Our thresholds for detecting differences are a roughly constant proportion of the size and the original stimulus.

Sensory Adaptation Sensory adaptation- the diminished sensitivity as a consequence of constant stimulation.[Ex: jumping into a

swimming pool, you shiver and complain about how cold it is. A short while later a friend arrives and you exclaim, “C’mon the waters fine”]

After constant exposure to a stimulus, our nerve cells fire less frequently. If we stare at an object without flinching, why does it not vanish from sight? Because our eyes are always

moving, quivering just enough to guarantee that retinal stimulation continually changes. If we could stop eyes from moving, would sights vanish as the coldness of the pool did?FINISH THIS PARTVision Our body has the ability to convert one sort of energy to another. Sensory transduction- conversion of one form of energy into another. In sensation, the transforming of

stimulus energies into neural impulses. Your eyes, for example, receive light energy and transform the energy into neural messages that the brain

processes into what you consciously see. The Stimulus Input: Light Energy What strikes our eyes is not color but pulses of electromagnetic energy that our visual system experiences as

color. What we see as visible light is a thin slice of the whole spectrum of electromagnetic radiation. 2 physical characteristics of light and sound help determine our sensory experience of them. Light’s wavelength- the distance from the peak of one light or sound wave to the peak of the next.

Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission. –determines its hue-the color we experience, such as blue or green.

Intensity – the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determine by the wave’s amplitude[height]

The Eye Light enters the cornea- protects the eye and bends light to provide focus. Light then passes through the pupil-the adjustable opening in the center of the eye through which light

enters. The pupil’s size, amount of light entering the eye, is regulated by the iris-a ring of muscle tissue that forms

the colored proportion of the eye around the pupil that controls the size of the pupil opening. [Iris adjusts light intake by dilating and constricting in response to light intensity and to inner emotions]

Behind the pupil is a lens-the transparent structure behind the pupil that changes shape to help focus images on the retina.

Accommodation -the process by which the eye’s lens changes the shape to help focus images on the retina. The eyeballs light sensitive inner surface, containing the receptor rods and cones plus layers of neurons that

being the processing of visual information - retina. Retina doesn’t read the image as a whole. Millions of receptor cells convert light energy into neural

impulses. Acuity- sharpness of vision- can be affected by small distortions in the shape of the eye. Cornea and lens focus the image of any object on the retina. In nearsightedness-a condition in which nearby objects are seen more clearly than distant objects because

distant objects focus in front of the retina. [ focus light rays from distant objects in front of the retina] Study shows that 10% of kids who slept in the dark before age 2 later became nearsighted, as did 34% of

those who slept with a night light and 55% f those who slept in a lighted room. Farsightedness - the oppose of nearsightedness. A condition in which faraway objects are seen more clearly

than near objects because the image of near objects is focused behind the retina. [The light rays from nearby objects reach the retina before they have produced a focused image.]

The Retina Following a single particle of light energy into your eye, you would see that it first makes its way through

the retina’s outer layer of cells to its buried receptor cells, the rods – retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when ones don’t respond and cones.-receptor cells that are concentrated near the center of the retina and that function in daylight or in well lit conditions. The cones detect fine detail and give rise to color sensations.

Light energy striking the rods and cones produces chemical changes that generate neural signals. These signals activate the neighboring bipolar cells, which in turn activate the neighboring ganglion cells.

Axons from the network of ganglion cells converge to form an optic nerve that carries information from the eye to your brain.

Where the optic nerve leaves the eye there are no receptor cells-creating a blind spot. Cones are clustered around the fovea-the retina’s area of central focus- only contains cones, no rods. Cones have their own bipolar cells to help relay their individual messages to the cortex, preserving the

cone’s precise information and making them able to detect fine detail. [Rods have no hotline to he brain, they share bipolar cells with other rods, their individual messages get combined]

If illumination diminishes, the cones become ineffectual. The rods remain sensitive in dim light, because several rods will funnel their faint energy from dim light onto a single bipolar cell.

Cones-detail/ rods-faint light When you enter a dark room, your pupils dilate to allow more light to reach the rods in the retina’s

periphery. Usually takes 20 min for your eyes to fully adapt. Visual Information Processing The retina processes information before routing it to the cortex. The retina’s neural layers help analyze and

encode the sensory information. The information from the retina’s many receptor rods and cones is received and transmitted by the million or so ganglion cells, whose fibers make up the optic nerve.

FINISH THIS PART PG 204Feature Detection Hubel and Wiesal demonstrated that the brain has feature detector-nerve cells in the brain that respond to

specific features of the stimulus, such as shape, angle, or movement. [Ex. A given brain cell might respond maximally to a bar flashed at 2:00 tilt. If the bar is tilted further to 3:00 position, the cell quiets down. Feature detection cells pass this information to other cells that respond only to ore complex patterns.

Perceptions arise from the interaction of many neuron systems, each performing a simple task. The visual cortex passes this information along to the temporal and parietal cortex. [one temporal lobe area

behind your right ear enables you to perceive faces-if damaged you wouldn’t be able to recognize familiar faces]

Perrett identified nerve cells that specialize in responding to a gaze, head angle, posture. Although the same image continues to strike the retina, the brain constructs varying perceptions[Nekcer

cube- shifts every few seconds, even if it’s the same image] The brain activity that underlies perception combines sensory input with our assumptions and expectations. Arguments: some say that the any image, can be broken down into patterns of changing light intensity that

can be described mathematically. The brain may actually be processing mathematical like codes that represent a perceived image

Neuroscientists are stimulating the activity of the brain’s interconnected, multilevel neural networks. Goal is to build artificial vision systems that respond in the ways our own visual system responds. [Ex. Their stimulated neural networks respond as humans do to the illusory image of a triangle that is really made up of three pacman figures, as if they were reacting to a real triangle]

Parallel Processing Strange visual disabilities produced by strange brain damage:

-Mr. I, after a concussion at 65, can no longer see color, only shades of gray. Unlike most computers which do a step by step serial processing, our brains engage in parallel processing-

the processing of several aspects of a problem at the same time; the brains natural mode of information processing for many functions, including vision.

We construct our perceptions by integrating the work of different visual teams, working in parallel. Although brain has slow components, it has a lot of them. The brain must deploy many processing elements

cooperatively and run parallel to carry out its activities. The distribution of visual tasks to different neural work teams explains the peculiar cases of visual

disability. Having lost a portion of their brain’s visual cortex to surgery or stroke, people may experience blindness in part of their field of vision, phenom. called blind sight.

‘sight unseen’ is how Milner describes the brain’s tow visual systems. 1.’One gives us our conscious perceptions, and the one that guides our actions.’ 2. ‘the zombie within’-knowing more than you are aware of.

Other senses process information with similar speed .[Ex: Answering the phone, you recognize the friend calling from the moment she says ‘Hi’]

For this moment, distant brain areas collaborate and the result is something no single neural cluster could achieve: a conscious recognition.

Color Vision Tomato is everything but red. It reflects the long wavelengths of red. The color is our mental construction as

well. Color resides not in the object but in the theater of our brains. For 1 in 50 people, vision is color –deficient-and that person is usually male, because the defect is sex

linked. Helmholtz and Young knew that any color can be created by combing the light waves of the three primary

colors-red, green, blue. Concluded that the eye must have three types of receptors-one fro each primary color of light-Young-Helmholtz trichromatic theory

Mixing paints is subtractive color mixing because it subtracts wavelengths from the reflected light. More colors you mix in, the fewer wavelengths can be reflected back.

Mixing lights, is additive color mixing because the process adds wavelengths and thus increases light-combining primary colors produces white light.

Most color-deficient people aren’t color blind-usually lack red/green sensitive cones.[their vision is dichromatic[2 colors] instead of trichromatic, hard to distinguish green/red.

W see yellow when mixing red/green light. How can those blind to red and green still see yellow? Hering found a clue in the occurrence of afterimages. When staring at a green square for a while then look

at a white sheet f paper, you see red, greens opponent color. Stare at a yellow square and you will later see its opponent color, blue on white paper.

Said there were two additional color processes, one for red vs green/blue vs yellow. Hering’s opponent-process theory- the theory that opposing retinal processes[red-green, yellow-blue, white-

black] enable color vision. [Ex. Some cells are stimulated[‘on’] by green and inhibited[‘off’] by red, others are stimulated by red and inhibited by green]

You cannot simultaneously detect the opposing color at the same time as the original color. Color processing occurs in two stages. The retina’s red, green, and blue cones respond in varying degrees to

different color stimuli, as the Young Helmholtz trichromiatic theory suggested. Their signals are then processed by the nervous systems opponent process cells, en route to the visual cortex.

Color Constancy Our experience of color depends on something more than the wavelength reflected, it depends on the

surrounding context as well. [Ex. If you only part of a tomato, its color will seem to change as the light changes. But if you see the whole tomato as one in a bowl of fresh vegetables, its color will remain constant as the lighting and wavelengths shift]-color constancy-perceiving familiar objects as having consistent color even if changing illumination alters the wavelengths reflected by the object.

We see color thanks to our brains’ computations of the light reflected by any object relative to its surrounding objects.

Comparisons govern our perceptionsHearing Our hearing, or audition, is very adaptive.

We hear best those sounds having frequencies within a range that corresponds to the range of the human voice. Also very sensitive to faint sounds and differences in sounds.[differences in human voices, helping to recognize immediately the voice of almost anyone we know]

The Stimulus Input: Sound Waves Hit a piano key non-dominant the resulting stimulus energy is sound waves=jostling molecules of air, each

bumping into the next. The ears transform them into nerve impulses, which our brain decodes as sounds. Strength or amplitude of a sound wave determines their loudness. Waves vary in length, and therefore in frequency- the number of complete wavelengths that pass a pointing

a given time[ex. Per second] Their frequency determines their pitch- a tone’s highness or lowness. Long waves have low frequency and low pitch. /Short waves have high frequency and high pitch Decibels are the measuring unit for sound energy. The absolute threshold for hearing is arbitrarily defined as 0 decibels. Normal conversation is 10,000 times louder than a 20 decibel whisper. When prolonged, exposure to sounds above 85 decibels can produce hearing loss. The Ear To hear, we must convert sound waves into neural activity. Human ear does so with a intricate mechanical

chain reaction. First the visible outerear channels the sound waves through the auditory canal to the eardrum, a tight

membrane that vibrates with waves. The middle ear- the chamber between the eardrum and cochlea – a coiled, bony fluid filled tube in the inner

ear through which sound waves trigger nerve impulses-containing three tiny bones [hammer, anvil, and stirrup] that concentrate the vibrations of the eardrum on the cochlea’s oval window.

The incoming vibrations cause the cochlea’s membrane [oval window] to vibrate the fluid that fills the tube. This motion causes ripple in the basilar membrane, which is lined with hair cells, so named because of their tiny hair like projections.

At the end of this sequence, the rippling of the basilar membrane bends these hair cells. The movement of the hair cells triggers impulse sin the adjacent nerve fibers, which in turn converge to form the auditory nerve. Sound waves cause the hair cells of the inner ear to send neural messages up to the temporal lobes auditory cortex.

From vibrating air to moving piston to fluid waves to electrical impulses to the brain. Damage to hair cells=accounts for most hearing loss. Cochlea has 16000 hair cells. Deflect the tiny bundles of cilia on the tip of a hair cell by the width of an

atom and the alert hair cell triggers neural impulses. They are very sensitive, delicate and fragile. If you blast it with incessant jackhammer sounds the hair cells

cilia will begin to wither or fuse. We detect loudness by a soft pure tone activating only the few hair cells attuned to its frequency. Given

louder sound, sits neighbor hair cells also respond. Can interpret loudness by the number of activated hair cells.

Really loud sounds may seem equally loud to people with and without hearing loss. This is why hard of hearing people don’t want all sounds amplified, they like sounds compressed-soft

sounds are amplified more than loud sounds. How Do we Perceive Pitch? Helmholtz’s place theory-in hearing, the theory that links the pitch we hear with the place where the

cochlea’s membrane is stimulated.[ how we hear high pitched sounds] Frequency theory -in hearing, the theory that the rate of nerve impulses traveling nup he auditory nerve

matches the frequency of a tone, thus enabling us to sense its pitch[low pitched sounds] the brain can read pitch from the frequency of neural impulses.

Problem: individual neurons cant fire fast than 1000 times per second. How can frequency theory explain our sensing sounds w. frequencies above 1000 waves per second.

The volley principle-like soldiers who alternate firing so that some could shoot while others reload, a group of neural cells can alternate firing. By firing in rapid succession they can achieve a combined frequency above 1000 times per second.

How Do We Locate Sound? The placement of our ears allows us to enjoy stereophonic [3D] hearing. Two ears are better than one because-1. if a car to the right honks, your right ear receives a more intense

sound slightly sooner than your left ear. Like visual information, the brain uses parallel processing. Owls process timing differences in one neural

pathway ad intensity difference in another before emerging their information to find a sounds location. Because such sounds strike the two ears at the same time, you wont be able to locate the sound very well. It

is hard to pinpoint a sound when it comes from directly ahead, behind, above, or below. Hearing Loss and Deaf Culture Problems with the mechanical system that conducts sound waves to the cochlea cause conduction hearing

loss. If the eardrum is punctured of tiny bones of the middle ear lose their ability to vibrate, ear’s ability to

conduct vibrations diminishes. [digital hearing aids help by amplifying vibrations for frequencies in which ones hearing is weakest and also by compressing sound[amplifying soft sounds]

Damage to the cochlea’s hair cell receptors or their associated nerves can cause sensorineural hearing loss [nerve deafness] Usually caused by disease, biological changes linked with again, prolonged exposure to ear splitting noise.

Once destroyed, tissues remain dead. Only way to restore hearing for people with nerve deafness is a sort of bionic ear-a cochlear implant.

Tanslates sounds into electrical signals that, wired into the cochlea’s nerves, convey some information about sound to the brain. More than 90% of deaf children have hearing parents, must of whom want their kids to experience their world of sound and talk.

Deaf culture argues that deafness is not a disability. Sign is a complete language with its own grammar, syntax, and semantics. Those who learn only sign during childhood have difficulty later learning to read and write.

Deafness could = vision enhancement. Those who lose one channel of sensation do seem to compensate with a enhancement of their other sensory abilities. [Touch /visual usually]

Those whose hearing as diminished by age or illness-living outside deaf culture- are more likely to describe themselves as having an impairment or disability. 1% were born deaf of the people who experience hearing loss.

Those who lose their hearing need not think of themselves as disabled people but that they are persons with a disability.

Can be socially disabling if haven’t learned sign. Helen Keller said that blindness cuts people off from things, deafness cuts people off from people. The Other Senses For humans, major sense are seeing and hearing. Depend on them for communication.Touch Touch is essential to our development. Premature babies sent home sooner by hand massage. “sense of touch” is a mix of four distinct skin senses-pressure, warmth, cold, and pain. Within the skin are different types of specialized nerve endings. Touching various spots on the skin with a soft hair, a warm/cold wire, etc reveals that some spots are

sensitive to pressure, others to warmth, others to cold, and others to pain. Stroking adjacent pressure spots creates a tickle, repeated gentle stroking of a pain spot creates an itching

sensation, touching adjacent cold and pressure spots triggers a sense of wetness, stimulating nearby cold and warmth spots produces a feeling of ‘hot’.

Pain Pain is your body’s way of telling you that something has gone wrong.-tells you to change your behavior

immediately.

Rare people born without the ability to feel pain may experience severe injury without ever being alerted by pains danger signals.

What is Pain? Pain is a property not only of the sense but of the brain as well. Phantom limb sensations indicate that with pain, as with sights and sounds, the brain can misinterpret the

spontaneous central nervous system activity that occurs in the absence of normal sensory input. People with hearing loss experience the ‘sound of silence’-phantom sounds- a ringing in the ears sensation

known as tinnitus[ even people with disabilities regarding other senses experience these phantom happenings]

To see, hear, taste, smell, and feel, we require a body but also a brain. No brain, no pain. There is no one type of stimulus that triggers pain and no special receptors for pain. Melzack and Walls gate-control theory-the theory that the spinal cord contains a neurological ‘gate’ that

blocks pain signal or allows them to pass on to the brain. The ‘gate’ is opened by the activity of pains signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.

One way to treat chronic pain is to stimulate ‘gate closing’ activity in the large neural fibers. Rubbing the area around your stubbed toe will create competing stimulation that will block some of the pain messages.

There is more to pain than what stimulates the sense receptors-in your mind as well. There is more to our memories of pain than the pain we experienced. When patients recalled the pain of a

colon exam a month later, memories were dominated by the final[and worst] moments, not by how long the pain lasted.

Its better to taper down a painful procedure than to switch it off abruptly.Pain Control Should be treatable both physically and psychologically. Lamaze method of childbirth combines relaxation, counterstimulation[massage] and distraction. Distracting people or drawing their attention away from painful stimulation is an effective way to increase

pain tolerance Nurse might talk to needle shy patients a shot, patients in hospitals with rooms looking out on trees required

less pain medication. Taste Taste sensations are sweet, sour, salty, and bitter. Bitter- sensing and sweet- sensing receptors as well as a receptor for a fifth taste sensation-the meaty taste of

‘umami’[flavor enhancer monosodium glutamate] Taste is a chemical sense. In each little bump on the top and sides of your tongue are 200 more taste buds,

each containing a pore that catches food chemicals. These molecules are sensed by 50 to 100 taste receptor cells that project ante alike hairs into the pore.

Taste receptors reproduce themselves every week or two-incase you burn your tongue, it doesn’t matter. As you get older, number of taste buds decreases as does taste sensitivity. Our emotional responses to taste are hard wired- can see the reaction of something sweet in someone’s

facial expression People with no tongues can still taste with receptors in the back of their mouth. Cant taste nor smell most nutrients-protein, fat, starch.etc. Taste buds essential for taste, but more to taste than meets the tongue. Smell and sight play into the effect. Sensory interaction -the principle that one sense may influence another, as when the smell of food influences

its taste. Similarly, we perceive the location of the voice directly in front of us because we also see that person is in

front of us, not behind, above, or beneath us. Seeing the moth movements for ga while hearing ba we may perceive da-McGurk effect. Seeing, hearing, touching, tasting, and smelling are not totally separate channel. The brain blends their

inputs. Smell[olfaction] Breaths come in pairs-except at two moments-birth/death.

You inhale/exhale about 20,000 breaths of air each day. Bathing your nostrils in a stream of scent laden molecules.

You inhale something of whatever or whoever it is you smell Smell, like taste, is a chemical sense. We smells something when molecules of a substance carried in the air

reach a tiny cluster of 5 million receptor cells at the top of each nasal cavity. These olfactory receptor cells, respond selectively . they alert the brain through their axon fibers. And then

onward to the temporal lobes primary smell cortex and to the parts of the limbic system involved in memory and emotion.

Mothers can find their child through smell and form connections Odor molecules come in many shapes and sizes. Takes different receptors to detect them. The ability to identify scents peaks in early adulthood and declines thereafter. Find it hard to describe scents. We each have our own identifiable chemical signature. Animals that have twice as many olfactory receptors use scent to communicate and navigate. Odors can evoke memories and feeling. We have a capacity to recognize long forgotten odors and their

associated personal episodes. Body Position and Movement To know just how to move your arms, to grasp someone’s hand, you need a 6th sense. You need to know the

current positions your arms and hands and the be aware of their changing positions as you move them. We come equipped with millions of position and motion sensors. Kinesthesis -the system for sensing the position and movement of individual body parts. Vision interacts with Kinesthesis. [stand with your right heel above your left toes. Now close your eyes and

you will probably wobble] Vestibular sense -the sense of body movement and position, including the sense of balance. Monitors the

head’s position and motion. The biological gyroscopes for this sense of equilibrium are in the inner ear. In the semicircular canals, look like a 3D pretzel, and the vestibular sacs, which connect the canals with the cochlea, substance that move when the head rotates or tilts.

This movement stimulates hair like receptors in these organs of the inner ear . Receptors ten send messages to the cerebellum at the back of the brain, enabling us to sense our body position and maintain our balance.

If you twirl around and stop all of a sudden, the fluid in your semicircular canals nor your kinesthetic receptors return to their neutral state right away. Aftereffect fools your dizzy brain that you’re still spinning.

Underlines the discussion of perceptual illusions.

Chapter 6: PerceptionI. Selective Attention: At any moment we focus our awareness on only a limited aspect of all that we experience. Cocktail party effect: the ability to attend selectively to only one voice too many. at the level of conscious awareness, whatever has your attention pretty much has your undivided attention. A University of Utah experiment shows that students conversing on a cellphone were slower to detect and respond to tragic signals during a driving simulation.

Change blindness: a lack of awareness; focusing attention on one specific thing can distract and leave a person blind from everything else around him or her. Although a perception requires attention, even unattended stimuli sometimes have subtle effects. i.e. If someone at a loud party audibly speaks your name, your attuned perceptual system may bring the voice to consciousness.

II. Perceptual Illusions: Illusions reveal the ways we normally organize and interpret our sensations. Distance, width, height, color, light, etc. are factors that contribute to illusions. Psychology’s emphasis on visual illusions reflects vision’s preeminence among our senses.

Visual capture: the tendency for vision to dominate the other senses. vision captures the other senses. i.e. People feel a touch where they see it rather than where it is.

III. Perceptual Organization: Gestalt: an organized whole. Gestalt psychologists emphasize our tendency to integrate pieces of information

into meaningful wholes. It describes how we organize our sensations into perceptions. Once a gestalt is made, it will always be perceived.

top-down processing: uses our experiences and expectations to interpret those sensations. Bottom-up processing: starting with entry-level sensory analysis. Sensation and perception blend into one continuous process, progressing upward from specialized detector cells

and downward from our assumptions. We constantly filter sensory information and infer perceptions in ways that make sense to us. Form Perception: to recognize a face, our first perceptual task is to perceive any object, called the figure, as distinct from its

surroundings, called the ground. Figure-ground: the organization of the visual field into objects (figures) that stand out from its surroundings

(grounds). Reversible figure-and-ground illustrations demonstrate that the same stimulus can trigger more than one

perception. To bring order and form to the basic sensations, our minds follow certain rules for grouping stimuli together. Proximity: we group nearby figures together. We see not six separate lines, but three sets of two lines. Similarity: figures similar to each other we group together. We see the triangles and circles as vertical columns

of similar shapes, not as horizontal rows of dissimilar shapes. Continuity: we perceive smooth, continuous patterns rather than discontinuous ones. This pattern could be a

series of alternating semicircles, but we perceive it as two continuous lines--- one wavy, one straight. Connectedness: when they are uniform and linked, we perceive spots, lines, or areas as a single unit. Closure: we fill in gaps to create a complete, whole object. Thus we assume that circles are complete but

partially blocked by the illusory triangle. Add nothing more than little line segments that close off the circles and now your brain stops constructing a triangle.

Depth Perception: the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.

In an experiment conveyed by Gibson and Walk, 6-14 month-old infants refused to crawl out onto a glass surface. Perhaps by crawling age the infants had learned to perceive depth.

During the first month of life. Human infants turn to avoid subjects coming directly at them but remain unbothered by anything approaching at an angle that would not hit them.

Biological maturation predisposes our wariness of heights, experience amplifies it. Binocular cues: depth cues, such as retinal disparity and convergence, that depend on the use of two eyes. Monocular cues: distance cues, such as linear perspective and overlap, available to either eye alone. Binocular cues are important in judging the distance of nearby objects. retinal disparity: a binocular cue for perceiving depth; by comparing images from two eyeballs, the brain

computes distance--- the greater the disparity (difference) between the two images, the closer the object. The creator of three-dimensional (3-D) movies stimulates or exaggerates retinal disparity by photographing a

scene with two cameras placed a few inches apart. When we view the movie through spectacles that allow the left eye to see only image from the left camera and

the right eye only the image from the right camera, the 3-D effect mimics normal retinal disparity. Perception is not merely projecting the world onto our brains. Rather, sensations are disassembled into

information bits that the brain then reassembles into its own functional model of the external world. Our brains construct our perceptions. Convergence: a neuromuscular cue caused by the eyes’ greater inward turn when they view a near object. It is

the extent to which the eyes converge inward when looking at an object.

Relative size: if we assume that two objects are similar in size, we perceive the one that casts the smaller retinal image as farther away.

Interposition: if one object partially blocks our view of another we perceive it as closer. Relative clarity: because light from distant objects passes through more atmosphere, we perceive hazy objects

as farther away than sharp, clear objects. Texture gradient: a gradual change from a coarse, distinct texture to a fine, indistinct texture signals increasing

distance. Relative height: we perceive objects higher in our field of vision as farther away. It may contribute to the

illusion that vertical dimensions are longer than identical horizontal dimensions. Relative motion (motion parallax): as we move, objects that are actually stable may appear to move. Objects

beyond the fixation point appear to move with you: the farther away the object, the lower its apparent speed. Linear perspective: parallel lines appear to converge with distance. The more the lines converge, the greater

their perceived distance. Light and shadow: nearby objects reflect more light to our eyes. Thus, given two identical objects, the dimmer

one seems farther away. Shading produces a sense of depth consistent with the assumed light source. Artists use monocular cues to convey depth and distance on a flat canvas.

Motion Perception A person can perceive motion because the brain computes motion based partly on its assumption that shrinking

objects are retreating and enlarging objects are approaching. Larger objects appear to move more slowly than small objects--- an illusion that contributes to car-train crashes. Stroboscopic movement: it occurs when the brain will also interpret a rapid series of slightly varying images as

continuous movement. By flashing 24 still pictures each second, a motion picture creates perceived movement. This motion is

constructed in our heads. Phi phenomenon: an illusion of movement created when two or more adjacent lights blink on and off in

succession. Perceptual constancy: perceiving objects as unchanging (having consistent lightness, color, shape and size)

even as illumination and retinal images change. Perceptual constancy allows us to identify things regardless of its angle, distance and illumination by which we

view them. In less than it takes to draw a breath, information reaching your eyes has been sent to your brain, where work

teams comprising millions of neurons have extracted the essential features, compared them with stored images, and identified the person.

Shape constancy lets us perceive the form of familiar objects as constant even while our retinal images of them change.

Moon illusion: cues to objects’ distances at the horizon make the moon behind them seem farther away than the moon high in the night sky. Thus, the horizon moon seems larger. Take away the cues and the object immediately looks smaller.

Our occasional misperceptions reveal the workings of our normally effective perceptual processes. Lightness constancy: we perceive an object as having a constant lightness even when its illumination varies. Perceived lightness depends on relative luminance- the amount of light an object reflects relative to its

surroundings. Perceived lightness stays roughly constant, given an unchanging context. It changes with context. Form perception, depth perception, motion perception and perceptual constancy illuminate how we organize our

visual experiences. Perceptual organization applies to other senses, too. Perceptual organization is also a process that involves not only organization but interpretation--- discerning

meaning in what we perceive.

IV. Perceptual Interpretation:

German philosopher Immanuel Kant maintained that knowledge comes from our inborn ways of organizing sensory experiences while British philosopher John Locke argued that through our experiences we also learn to perceive the world.

Writing to John Locke, William Molyneux wondered whether “a man born blind, and now adult, taught by his to distinguish between a cube and a sphere” could, if made to see, visually distinguish the two. John Locke said no because the

man would never have learned to see the difference. Cataracts: clouded lenses that allowed them to see only diffused light. When their cataracts were removed, the

formerly blind patients often could not recognize by sight objects that were familiar by touch. A person’s cortical cells will not develop normal connections if it lacks stimulation. The effects of visual experiences in during infancy suggest there is a critical period for normal sensory and

perceptual development. Experience guides and sustains the brain’s neural organization. Human infants born with cataracts will typically have a corrective surgery within a few months. The brain

network responsible for the corrected eye then rapidly develops, enabling improved visual acuity with as little as one hour’s visual experience.

We retain the imprint of early visual experiences far into the future. Perceptual adaptation: in vision, the ability to adjust to an artificially displaced or even inverted visual field. Perceptual set: a mental predisposition to perceive one thing and not another. Once we have formed a wrong idea about reality, we have more difficulty seeing the truth. Our perceptual set can influence what we hear as well as what we see. What we perceive comes not just from the world “out there” but also from what’s behind our eyes and between

our ears. Through experience we form concepts, or schemas, that organize and interpret unfamiliar information. Children’s drawings give us a way to glimpse their developing perceptual schemas. To 3- and 4-year-olds, a

face is a more important human feature than a body. From ages 6 and 8, children’s schemas for bodies become more elaborate, and so do their drawings.

Our schemas for faces prime us to see facial patterns even in random configurations. A given stimulus may trigger radically different perceptions, partly because of our differing schemas, but also

because of the immediate context. The brain can work backward in time to allow a later stimulus to determine how we perceive an earlier one. The

context creates an expectation that, top-down, influences our perception as we match our bottom-up signal against it. The effects of perceptual sets and context show how experience helps us construct perception. Perception is fed by sensation and cognition. Human factors psychology: a branch of psychology that explores how people and machines interact and how

machines and physical environments can be adapted to human behavior. Understanding human factors can do more than enable us to design for reduced frustration; it can help avoid

disaster. Designers and engineers should consider the human factor, by designing things to fit people, by being mindful

of the curse of knowledge and by user-testing their inventions before production and distribution. extrasensory perception (ESP): the controversial claim that perception can occur apart from sensory input.

Said to include telepathy, clairvoyance, and precognition. Parapsychologists: those who study paranormal occurrences. Parapsychology: the study of paranormal phenomena, including ESP and psychokinesis. if ESP is real, we would never to overturn the scientific understanding that we are creatures whose minds are

tied to our physical brains and whose perceptual experiences of the world are built of sensations. Claims of ESP: astrological prediction, psychic healing, communication with the dead, and out-of-body

experiences. Telepathy: mind-to-mind communication-one person sending thoughts to another or perceiving another’s

thoughts. Clairvoyance: perceiving remote events, such as sensing that a friend’s house is on fire. Precognition: perceiving future events, such as a political leader’s death or a sporting event’s outcome. Psychokinesis: “mind over matter”

a reproducible ESP phenomenon has never been discovered, nor has anyone produced any individual who can convincingly demonstrate psychic ability.

Testing is a scientific attitude that has led believers and skeptics to agree that what parapsychology needs to give it credibility is a reproducible phenomenon and a theory to explain it.

Ganzfeld procedure: it would place you in a reclining chair, play hissing white noise through headphones, and shine diffused red light through halved Ping-Pong balls strapped over your eyes.

this reduction of external distractions would put you in an ideal state top receive thoughts from someone else, which you might hear as small voices from within.

To feel awe and to gain a deep reverence of life, we do not need to look any further than our own perceptual system and its capacity for organizing formless nerve impulses into colorful sights, vivid sounds and evocative smells.

(add Chapter 3 [7] on hypnosis)