Chapter 5 Sensation And Perception

Front 1

Sensation pg180

Back 1

The process by which 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 image. Sensation represents the first of steps in processing of incoming information.

Front 2

Perception pg181

Back 2

A process that makes sensory patterns meaningful. It is perception that makes these words meaningful, tather than just a string of visual patterns. To make this happen, perception draws heavily on memory, motivation, emotion, and other psychological processes.

Front 3

Just noticeable difference (JND) pg185

Back 3

Same as the difference threshold.

Front 4

Transduction pg182

Back 4

Transformation of one form of energy into another-especially the transformation of stimulus information into nerve signals by the sense organs. Without transduction, ripe tomatoes would not appear red (r pinkish-gray, in the case of tomatoes purchased in many grocery stores).

Front 5

Weber's Law pg185

Back 5

The 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 small when the stimulus intensity is low. (This concept has no connection with Ann Weber, one of your authors.)

Front 6

Sensory Adaption pg183

Back 6

Loss of responsiveness in receptor cells after stimulation has remained unchanged for a while, as when a swimmer becomes adapted to the temperature of the water.

Front 7

Signal detection theory pg185

Back 7

Explains how we detect signals, " consisting of stimulation affecting our eyes, ears, noses, skin, and other sense organs. Signal detection theory says that sensation is a judgement the sensory system makes about incoming stimulation. Often, it occurs outside of consciousness. In contrast to older theories from psychophysics, signal detection theory takes observer characteristics into account.

Front 8

Absolute Threshold pg 184

Back 8

the amount of stimulation necessary for a stimulus to be detected. In practice, this means that the presence or absense of stimulus is detected correctly half the time over many trials.

Front 9

Retina pg188

Back 9

The thin light-sensitive layer at the back of the eyeball. The reina contains millions of photoreceptors and other nerve cells.

Front 10

Difference Threshold pg184

Back 10

The smallest amount by which a stimulus can be changed and the difference be detected half the time.

Front 11

Photoreceptors p.188

Back 11

Light-sensitive cells (neurons) in the retina that convert light energy to neural impulses. The photreceptors are as far as light gets into the visual system.

Front 12

Rods p. 188

Back 12

Photoreceptors in the retina that are especially sensitive to dim light but not to colors. Strange as it may seem, they are rod-shaped.

Front 13

Brightness p. 191

Back 13

A psychological sensation caused by the intensity of light waves.

Front 14

Cones p. 190

Back 14

Photoreceptors in the retina that are expecially sensitive to colors but not to dim light. You may have guessed that cones are cone shaped.

Front 15

Color p. 192

Back 15

Also called hue. Color is not a preoperty 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.

Front 16

Fovea p.190

Back 16

The tiny area of sharpest vision in the retina.

Front 17

Electromagnetic spectrum
p. 193

Back 17

The entire range of electromagnetic energy, including radio waves, X-rays, microwaves, and visible light.

Front 18

Optic Nerve p. 190

Back 18

The bundle of neurons that carries visual information from the retina to the brain.

Front 19

Visible spectrum p. 193

Back 19

The tiny part of the electromagnetic spectrum to which our eyes are sensitive. The visible spectrum of other creatures may be slightly different from our own.

Front 20

Blind Spot p. 190

Back 20

The point where the optic nerve exits the eye and where there are no photoreceptors. Any stimulus that falls on the area cannot be seen.

Front 21

Trichomatic Thoery p. 193

Back 21

The idea that colors are sensed by three different types of cones sensitive to light in the red, blue, and green wavelengths. The trichomatic theory explains the earliest stage of color sensation.

Front 22

Opponent-Process thoery p.194

Back 22

The idea that cells in the visual system process colors in complementary pairs, such as red or green or as yellow or blue. The opponent process theory explains color sensation from the bipolar cells onward in the visual system.

Front 23

Tymanic membrane p. 195

Back 23

The Eardrum.

Front 24

Afterimages p. 194

Back 24

Sensations that linger after the stimulus is removed. Most visual afterimages are negative afterimages, which appear in reversed colors.

Front 25

Cochlea p. 195

Back 25

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

Front 26

Color Blindness p. 194

Back 26

Typically a genetic disorder (although sometimes the result of trauma, as in the case of Jonathon) that prevents an individual from discriminating certain colors. The most common form is red-green color blindness.

Front 27

Basilar Membrane p. 195

Back 27

A thin strip 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 association neurons become excited. As a result, the sound waves are cconverted (trasduced) into nerve activity.

Front 28

Frequency p. 195

Back 28

The number of cycles completed by a wave in a given amount of time, usually a second.

Front 29

Pitch p.196

Back 29

A sensory characteristic of sound produced by the frequency of the wound wave

Front 30

Amplitude p. 195

Back 30

The physucal strength of a wave. This is usually measured from peak (top) to valley (bottom) on a graph of the wave.

Front 31

Loudness p. 198

Back 31

A sensory characteristic of sound produced by the amplitude (intensity) of th sound wave.

Front 32

Timbr p. 198

Back 32

The quality of a sound wave that derives from the wave's complexity ( combination of pure tones). Timbre comes from the Greek word for "drum," as does the term tympanic membrane, or eardrum.

Front 33

Gustation p. 201

Back 33

The sense of tast-from the same word root as "gusto"-also called the gustatory sense.

Front 34

Vestibular sense p. 199

Back 34

the sense of body orientation with respect to gravity. The vestibular sense is closely associated with the inner ear and, in fact, is carried to the brain on a branch of the auditory nerve.

Front 35

Skin senses p. 202

Back 35

Sensory systems for processing touch, warmth, cold, texture, and pain.

Front 36

Kinesthetic sense p.199

Back 36

The sense of body position and movement of body parts relative to each other (also called kinesthesis).

Front 37

Gate-control theory p. 202

Back 37

An explanation for pain control that proposes we have a neural "gate" that can, under some circumstances, clock incoming pain signals!

Front 38

Olfaction p. 199

Back 38

The sense of smell

Front 39

Placedo effect p.203

Back 39

A response to a placebo ( a fake drug), caused by subjects' belief that they are taking real drugs.

Front 40

Pheromones p. 200

Back 40

Chemical signals released by organisms to communicate with other members of their species. Pheromones are often used by animals as sexual attractants. It is unclear whether or not humans employ pheromones.

Front 41

Percept p. 205

Back 41

The meaningful product of perception-often an image that has been associated with concepts, memories of events, emotions, and motives.

Front 42

Feature detectors p. 205

Back 42

Cells in the cortex that specialize in extracting certain features of stimulus.

Front 43

Ambiguous figures p. 207

Back 43

Images that are capable of more than one enterpretation. There is no "right" way to see an ambiguous figure!

Front 44

Binding Problem p. 205

Back 44

Refers to the process used by the brain to combine (or "bind") the results of many sensory operations into a single percept. This occurs, for example, when sensations of color, shape or boundary, and texture are combined to produce the percept of a person's face. No one knows exactly how the brain does this. Thus, the binding problem is one of the major unsolved mysteris in psychology.

Front 45

Gestalt Psychology p. 212

Back 45

From a German word ( pronouced Gush-tawlt) that means "whole: or "form" or "configuration." ( A gestalt is also a percept.) The Gestalt psychologists believed that much of perception is ahped by the innate factors built into the brain.

Front 46

Bottom-up processing p. 206

Back 46

Perceptual analysis that emphasizes the perceiver's expectations, conept memories, and other cognitive factors, rather than being driven by the characterisitcs of the stimulus."Top" refers to a mental set in the brain-which stands at the "top" of the perceptual processing system.

Front 47

Figure p. 212

Back 47

The part of a pattern that commandsattention. The figure stands out against the ground.

Front 48

Perceptual constancy p 206

Back 48

The ability to recognize the same object as remaining "constant" under different conditions such as changes in illumination, distance, or location.

Front 49

Ground p. 212

Back 49

Tha part of a pattern that does not command attention; the background.

Front 50

Illusion p. 207

Back 50

You have experienced an illusion when you have a demonstrably incorrect perception of a stimulus pattern, especially one which also fools others who are observing the same stimulus. (If no one else sees it the way you do, you could be having delusion or hallucination. We'll take those terms up in a later chapter on mental disorder.)

Front 51

Closure p. 212

Back 51

The Gestalt principle that identifies the tendency to fill in gaps in figures and to see incomplete figures as complete.

Front 52

Laws of perceptual grouping p.213

Back 52

The Gestalt principles of similarity, proximity, continuity, and common fate. These "laws" suggest how our brains prefer to group stimulus elements together to form a percept. ( gestalt)

Front 53

Law of Pragnanz p. 214

Back 53

the MOST General Gestalt Principle:
That the simplest organization, requiring the least cognitive effort, will emerge as the figure. Pragnanz shares a common root with pregnant, and so it carries the idea of a "fully developedfigure." That is, our perceptual systems prefer to see a fully developed Gestalt, such as a complete circle-as opposed to a broken circle.

Front 54

Law of similarity p.213

Back 54

The Gestalt principle that we tend to group objects together in our perceptions.

Front 55

Binocular cues p. 214

Back 55

Informationt taken in by both eys that aids in depth perception, including binocular convergence and retinal disparity.

Front 56

Law of proximity p.213

Back 56

the Gestalt principle that we tend to group objects together when they are near each other, Proximity means nearness.

Front 57

Monocular cues p. 215

Back 57

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

Front 58

Law of continuity p.213

Back 58

The Gestalt principle that we prefer perceptions of connected and continuous figures to disconnected and disjointed one.

Front 59

Learning-based inference p.216

Back 59

The view that perception is primarily shaped by learning ( or experience), rather than by innate factors.

Front 60

Law of common fate p. 214

Back 60

The Gestalt principle that we tend to group similar objects together that share a mommon motion or destination

Front 61

Perceptual Set p. 217

Back 61

Readiness to detect a particular stimulas in a given context.- as when a person who is afraid interprets an unfamiliar sound in the night as a threat!