Sensation & Perception

Question 1

absolute threshold

Answer 1

the minimum of stimulus energy that is needed to activate a sensory system

Question 2

difference threshold

Answer 2

how different 2 stimuli (in magnitude) must be before they are perceived to be different

Question 3

just noticeable difference (jnd)

Answer 3

the amount of change necessary to predict the difference between 2 stimuli

Question 4

Weber’s Law

Answer 4

ration of absolute difference of 2 stimuli is important in producing a jnd

Question 5

Fechner’s Law

Answer 5

expresses the relationship between the intensity of the sensation and the intensity of the stimulus

Question 6

receptors

Answer 6

respond to physical stimuli

Question 7

transduction

Answer 7

translates physical energy to neural impulses

Question 8

projection areas

Answer 8

brain areas that further analyze sensory input

Question 9

cornea

Answer 9

clear, domelike window in front of eye, gathers & focus incoming light

Question 10

pupil

Answer 10

hole in the iris, contracts in bright light, expands in dim light

Question 11

iris

Answer 11

colored part- controls size of pupil & amount of light entering eye

Question 12

lens

Answer 12

lies right behind iris, helps control curvature of the light coming in and can focus new or distant objects on the retina

Question 13

retina

Answer 13

in the back of the eye and is like a screen filled w/ neural elements and blood vessels –> image detecting part of the eye

Question 14

cones

Answer 14

• used for Color vision and for perceiving fine detail

- most effective in bright light, and allows us to see chromatic and achromatic colors

Question 15

rods

Answer 15

• in reduced illumination, function best and allow perception only of achromatic colors
• have low sensitivity to detail and are not involved in color vision
• many more rods than cones

Question 16

rhodopsin

Answer 16

photo pigment

Question 17

illumination

Answer 17

a physical, objective measurement that is simply the amount of light falling on a surface

Question 18

brightness

Answer 18

the subjective impression of the intensity of a light stimulus

Question 19

color perception

Answer 19

related to the wavelength of the light entering the eye

Question 20

Young-Helmhotz (Trichromatic Theory)

Answer 20

suggests that the retina contains 3 different types of color receptors (cones), which are differentially sensitive to different colors

Question 21

Ewald Hering

Answer 21

primary colors arranged in opposing pairs

Question 22

depth perception

Answer 22

when one object (A) covers or overlaps w/ object (B), we see object (A) as being in front

Question 23

Perception of Form

Answer 23

• perceptual objects exist only in our mind, and not in the retinal image
• figure: integrated visual experience that stands out at the center of attention
• ground: the background against which the figure appears

Question 24

Gestalt Laws of Organization- proximity

Answer 24

elements close to one another tend to be perceived as a unit

Question 25

Gestalt Laws of Organization-similarity

Answer 25

elements that are similar to one another tend to be grouped together

Question 26

Gestalt Laws of Organization-good continuation

Answer 26

elements that appear to follow in the same direction tend to be grouped together

Question 27

Gestalt Laws of Organization- closure

Answer 27

the tendency to see incomplete figures as being complete

Question 28

Gestalt Laws of Organization-pragnanz

Answer 28

perceptual organization will always be as “good” (I.e regular, simple, symmetrical, etc) as possibe

Question 29

bottom-up processing

Answer 29

(data driven) object perception that responds directly to the components of incoming stimulus on the basis of fixed rules

Question 30

top-down processing

Answer 30

(conceptually driven) object perception that is guided by conceptual processes such as memories & expectations

Question 31

Visual Constancies- size constancy

Answer 31

tendency for the perceived size of an object to remain constant despite variation in the size of its retinal image

Question 32

Visual Constancies- shape constancy

Answer 32

tendency for the perceived shape of an object to remain constant despite variation in the shape of its retinal image

Question 33

Visual Constancies-lightness constancy

Answer 33

tendency for the perceived lightness of an object to remain constant despite changes in illumination

Question 34

Visual Constancies- color constancy

Answer 34

tendency for the perceived color of an object to remain constant despite changes in the spectrum of light falling on it

Question 35

frequency

Answer 35

the # of cycles/second; measured in Hz

Question 36

intensity

Answer 36

the amplitude of the sound wave; measured in decibels

Question 37

pitch

Answer 37

the subjective experience of the frequency of the sound

Question 38

loudness

Answer 38

the subjective experience of the intensity of the sound

Question 39

timbre

Answer 39

refers to the quality of the sound