Sensation And Perception

Front 1

Endogenous attention

Back 1

you choose what to pay attention to

Front 2

Exogenous attention

Back 2

the environment determines what you pay attention to

Front 3

saccades

Back 3

small, rapid eye movements

Front 4

fixations

Back 4

pauses in eye movements that indicate where a person is attending (approx. 3 per second)

Front 5

stimulus salience

Back 5

areas of stimuli that exogenously capture attention due to their properties (color contrast, orientation)

Front 6

scene schema

Back 6

prior knowledge about what is found in typical scenes (influence fixations)

Front 7

task demands

Back 7

override stimulus saliency and influence fixations

Front 8

inattentional blindness

Back 8

a stimulus is not perceived even when the person is looking directly at it

Front 9

change blindness

Back 9

a change from one image to another is not noticed

Front 10

binding

Back 10

the process by which features are combined to create perception of coherent objects

Front 11

binding problem

Back 11

features of objects are processed separately in different areas of the brain

Front 12

feature integration theory

Back 12

object > preattentive stage > focused attention stage > perception

Front 13

conjunction search

Back 13

finding target with two or more features

Front 14

illusory conjunctions

Back 14

features that should be associated with an object become incorrectly associated with another

Front 15

balint's syndrome

Back 15

patients with parietal lobe damage show lack of focused attention results in incorrect combination of features

Front 16

attentional capture

Back 16

motion attracts attention to the moving object

Front 17

5 ways to perceive motion

Back 17

real motion, motion aftereffect, illusory motion, induced motion, implied motion

Front 18

three situations that lead to motion perception >>> 1.

Back 18

an object moves, and the observer is stationary. movement creates an image that moves on the observer's retina

Front 19

>>> 2.

Back 19

an object moves, and the observer follows the object with their eyes. the image is stationary on the retina

Front 20

>>> 3.

Back 20

an observer moves their eyes. image of environment moves across retina but environment is perceived as stationary

Front 21

corollary discharge theory

Back 21

movement perception depends on 3 signals:

1. motor signal (MS) - signal sent to eyes to move eye muscles

2. corollary discharge signal (CDS) - split from the motor signal

3. Image displacement signal (IDS) - movement of image stimulating receptors across the retina

Front 22

motor signal (MS)

Back 22

signal sent to eyes to move eye muscles

Front 23

corollary discharge signal (CDS)

Back 23

split from the motor signal

Front 24

Image displacement signal (IDS)

Back 24

movement of image stimulating receptors across the retina

Front 25

static eye looking at a moving person or eye following a moving person

Back 25

movement is perceived when comparator receives input from corollary discharge signal (CDS) or image displacement signal (IDS)

Front 26

eye looking arouns but nothing happens

Back 26

movement is not perceived when comparator receives input from both corollary discharge and image displacement signals at the same time

Front 27

optic array

Back 27

structure created by surfaces, textures, and contours, which change as the observer moves through the environment

Front 28

global optic flow

Back 28

overall movement of optic array; indicates that observer is moving and not the environment

Front 29

aperture problem

Back 29

the direction of part of a moving object does not always provide enough information about how the whole object is moving

Front 30

solution to aperture problem

Back 30

how the ends of an object move determines how you see the parts moving; end-stopped cortical cells find the moving ends

Front 31

biological motion

Back 31

movement of person or other living organism

Front 32

point-light walker stimulus

Back 32

biological motion made by placing lights in specific places on a person that gains structure from motion

Front 33

motion aftereffect

Back 33

movement appears to occur in the opposite direction from the original movement, sometimes called the waterfall illusion; wearing out motion sensors

Front 34

illusory motion

Back 34

apparent movement between objects; stationary stimuli are presented in slightly different locations

Front 35

static illusory motion

Back 35

still not understood, but believed to involve motion sensitive cells and changes in contrast; leads to similar activation as real motion and phi phenomenon

Front 36

induced motion

Back 36

movement of one object results in the perception of movement in another object

Front 37

implied motion

Back 37

imagining motion suggested by images; pictures that are stationary depict an action that involves motion

Front 38

representational momentum

Back 38

observers show that the implied motion is carried out in the observer's mind

Front 39

functions of color vision

Back 39

color signals help us classify and identify objects; color facilitates perceptual organization of elements into objects; color vision may provide an evolutionary advantage in foraging for food

Front 40

superimposition

Back 40

different wavelengths of light at the same location don't mix into one wavelength of light - they exist separately in the same location

Front 41

achromatic colors

Back 41

contain no hues - white black and gray tones

Front 42

hue

Back 42

changing wavelength

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saturation

Back 43

adding white (all wavelengths) to a color results in LESS saturated color

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intensity

Back 44

energy or amount of light

Front 45

additive color mixture

Back 45

mixing LIGHTS of different wavelengths; superimposing short and medium-long light waves leads to the perception of white

Front 46

trichromatic theory of color vision

Back 46

three cone types that are sensitive to different ranges of wavelengths; combinations of the responses across all three cone types lead to perception of all colors

Front 47

recognition-by-components theory

Back 47

objects are recognized by volumetric features (geons)

Front 48

Geons

Back 48

36 volumetric features that combine to make all 3-D objects; include cylinders, rectangular solids, and pyramids

Front 49

geon view-invariant properties

Back 49

aspects of the object that remain visible from different viewpoints

Front 50

geon non-accidental properites

Back 50

properties of edges in the retinal image that correspond with the 3-D environment

Front 51

principle of componential recovery

Back 51

the ability to recognize an object if we can identify its geons

Front 52

motion agnosia

Back 52

damage to the cortex resulting in an inability to perceive movement

Front 53

opponent-process theory of color vision

Back 53

colors are discriminated by opposing responses generated by blue and yellow, and by green and red

Front 54

monochromat

Back 54

person who needs only one wavelength to match any color

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dichromat

Back 55

person who needs only two wavelengths to match any color

Front 56

trichromat

Back 56

three wavelengths needed to match any color

Front 57

chromatic adaptation

Back 57

adapting when the stimulus color selectively bleaches a specific cone pigment

Front 58

memory and color

Back 58

past knowledge impacts color perception

Front 59

the ratio principle

Back 59

two areas that reflect different amounts of light look the same if the ratios of their intensities are the same

Front 60

occlusion

Back 60

when one object partially covers another

Front 61

relative height

Back 61

base of objects below the horizon that are higher are more distant but objects above the horizon lower in the visual field are more distant

Front 62

relative size

Back 62

when objects are equal in size, the closer one will take up more of your visual field

Front 63

perspective convergence

Back 63

parallel lines appear to come together in the distance

Front 64

familiar size

Back 64

distance based on our knowledge of object size

Front 65

atmospheric perspective

Back 65

distance objects are fuzzy and have blue tint

Front 66

texture gradient

Back 66

equally spaced elements are more closely packed as distance increases

Front 67

shadows

Back 67

indicate where objects are located

Front 68

motion parallax

Back 68

close objects in direction of movement glide rapidly past but objects in the distance appear to move slowly

Front 69

deletion and accretion

Back 69

objects are covered or uncovered as we move relative to them; covering an object is deletion, uncovering an object is accretion

Front 70

binocular disparity

Back 70

difference in images from two eyes; difference can be described by examining corresponding points on the two retinas

Front 71

the horopter

Back 71

imaginary sphere that passes through the point of focus; objects on the horopter fall on the corresponding points on the two retinas

Front 72

size constancy

Back 72

perception of an object's size remains relatively constant; this effect remains even if the size of the retinal image changes

Front 73

size-distance scaling equation

Back 73

S = R x D; S = object's perceived size, R = retinal size, D = perceived distance; the changes in PERCEIVED distance and retinal size balance each other