Chapter 5: Sensation & Perception

Question 1

Transduction

Answer 1

process by which sensory stimuli are converte to neural signals

Question 2

Sensation

Answer 2

stimulation of sense organs; absorption of energy by sensory organs

Question 3

Perception

Answer 3

selection, organization, and interpretation of sensory information;

organization and translation of sensory information into something meaningful

Question 4

Physical property of light and related perception

wavelength/frequency

Answer 4

hue (colour)

Question 5

Physical property of light and related perception

Amplitude

Answer 5

brightness

Question 6

Physical property of light and related perception

purity

Answer 6

saturation

Question 8

Timbre

Answer 8

purity of sound;
pure tone that has only one frequency and one amplitude

Question 9

Blindspot

Answer 9

nerves run from retina to brain converge in one spot where no receptor cells are present; image falling on this spot cannot be seen

Question 10

Receptor cells

Answer 10

• in the retina’s innermost layer
• sensitive to light
• rods > cones

Question 11

Fovea

Answer 11

tiny spot in the center of the retina that only contains cones; rods outnumber cones in the periphery of the retina

Question 12

Cones

Answer 12

colour vision
daylight vision
visual acuity
3 pigments

receptor cells

Question 13

Rods

Answer 13

peripheral vision
night vision
one pigment

receptor cells

Question 14

Processing of visual information in the brain

Answer 14

Where: thalamus, occipital lobe, parietal lobe, temporal lobe
What: perception of brightness, orientation, form, colour, motion, & depth

Question 14

Processing visual information in the retina

Answer 14

Where: receptive field of ganglion cell
What: perception of light/dark contrast or simple geometric shapes

Question 15

Center-surround antagonism

Answer 15

property of the receptive field of a ganglion cell

Question 16

Feature of the center of receptive field

Answer 16

excitatory; rate of firing a nerve impulse increases when light falls on the center

Question 17

Feature of the surrounding of receptive field

Answer 17

inhibitory; rate of firing nerve impulse decreases when light falls on the surrounding area

Question 18

Information processing in the brain

Thalamus

Answer 18

perception of brightness

Question 19

Information processing in the brain

Primary visual cortext in occipital lobe

Answer 19

perception of orientation

Question 20

Information processing in the brain

Inferior temporal lobe

Answer 20

perception of form and colour

Question 21

Information processing in the brain

Parietal lobe

Answer 21

perception of motion and depth

Question 22

Damage to the occipital lobe will result in a condition called:

Answer 22

blindsight

Question 23

Steps

Cat experiment by Hubel and Wiesel

Answer 23

• cat was shown a line in various orientation
• microelectrode was placed in cat’s primary visual cortex
• APs from individual neurons were recorded by oscilloscope

Question 24

# Findings Cat experiment by Hubel and Wiesel

Answer 24

- vertical line elicited rapid firing rate; - horizontal line elicited no response (firing rate at baseline measure); - tilted line elicited moderate firing rate

Question 25

# Conclusion Cat experiment by Hubel and Wiesel

Answer 25

- neurons are highly specialized; they respond to very specific stimuli

Question 26

Ventral Stream

Answer 26

- leads to temporal lobe - processes details of "what" objects are out there - the "what" pathway ## Footnote after visual information is processed in the primary visual cortex it is sent to two other cortical areas for further processing

Question 27

Agnosia

Answer 27

- individual suffers from agnosia when the ventral stream is damaged - there are multiple forms: visual-form agnosia, colour agnosia, face agnosia | know DF

Question 28

Visual-form agnosia

Answer 28

inability to recognize visual forms or familiar objects

Question 29

Colour agnosia

Answer 29

inability to recognize colours

Question 30

face agnosia

Answer 30

inability to recognize faces

Question 31

Dorsal stream

Answer 31

- leads to parietal lobe - processes the details of "where" objects are n "how" to interact with them - the "where" or "how" pathway - vision for action pathway - when damaged, individual cannot guide bodily movements based on visual information | know LM, RV, DF ## Footnote after visual information is processed in the primary visual cortex it is sent to two other cortical areas for further processing

Question 32

Color

Answer 32

psychological representation of a mixture of lights in different wavelengths

Question 33

Subtractive colour mixing

Answer 33

stars with light (white) colored filters between viewer and light source subtract wavelengths from the light, giving it colour | subtractive = mixing pigments ## Footnote middle is black

Question 34

Additive color mixing

Answer 34

starts without light (black) light sources of various wavelengths combine to form colors | additive = mixing lights ## Footnote middle is white

Question 35

Trichromatic theory of colour vision ## Footnote Weakness?

Answer 35

- human eye has three types of receptors with differing sensitivities to different light wavelengths - light of diff wavelengths stimulates three diff types of cone receptors in diff ways - ratio of activity of these 3 receptors creates our impression of different colors ## Footnote fails to explain complementary afterimage

Question 36

Opponent process theory of color vision

Answer 36

color perception depends on receptors that make antagonistic responses to three pairs of colors - opponent-process cells are inhibited by a color and have a burst of activity when it is removed

Question 37

Color Blindness

Answer 37

someone who is born with only one or two cone receptors - person unable to create colors depending on the type of receptor missing - most common deficiency is red or green - two receptors missing = no color

Question 38

Psychophysics

Answer 38

study of how physcial stimuli are related or translated into psychological experience - relationship can be modelled by Weber's law and Fechner's law

Question 39

Absolute Treshold

Answer 39

min amount of stimulation that an organism can detect - intensity level at which probability of detection is 50% - researchers found that there is no single stimulus intensity at which subject jumps from no detection to completely accurate detection (unlike neurons) - change of detecting stimulus increases gradually as stimulus intensity is increased

Question 40

Signal Detection Theory

Answer 40

detection of stimulus depends on: 1. intensity 2. psychological state of the individual or context of the situation two processes are involved: 1. sensory process 2. decision making process

Question 41

3 types of responses to decision outcomes for preceiver's response vs. stimulus

Answer 41

**1. unbiased responses** hit rate = correct rejection rate (95%); miss rate = false alarm rate (5%) **2. biased responses: YEA sayers** high hit rate & high false alarm rate **3. biased responses: NAY sayers** high correct rejection rate and high miss rate

Question 42

Just Noticeable Difference (JND)

Answer 42

smallest difference in the amount of stimulation that a specific sense can detect

Question 43

Weber's Law

Answer 43

size of JND is a constant proportion of the size of initial stimulus △I/I = K - constant increments in stimulus intensity prouce smaller and smaller increases in precieve magnitude of sensation

Question 44

Fechner's Law

Answer 44

subjective senstation is proportional to the log of intensity of stimulus S = k log R implication: psychological reality correlates with a physical reality - psychophysical parallelism Psycho = Physical | k = constant S = senstation (measured in JND) R = Reiz (stimulus)

Question 45

Factors that affect the outcome of perception

Answer 45

clarity of stimulus context way of presentation viewing percpective background knowledge of viewer focus of attention schema etc.

Question 46

Bottom-up processing

Answer 46

perception based on the physical features of the stimulus ## Footnote Data-driven processing

Question 47

Top-down processing

Answer 47

interpretation of sensory information based on knowledge, expectations, and past experience ## Footnote concept-driven processing

Question 48

# Two systems of thoughts Structuralism

Answer 48

breaks down whole into its parts method: introspection

Question 49

# Two systems of thoughts Gestalt Psychology

Answer 49

whole is more than the sum of its parts - integrating elementary components to form a whole - opposite of structuralism - a form of top-down/conceptually driven processing

Question 50

Principle of Closure

Answer 50

people may complete figures that actually have gaps in them

Question 51

Principle of Continuity

Answer 51

people tend to connect points that result in a straight or gently curve lines that create smooth patterns

Question 52

Principle of Similarity

Answer 52

people tend to group items that are similar in color, shape, brightness, etc. to form a unit

Question 53

Principle of Proximity

Answer 53

things that are close to one another seem to belon together - they form a unit

Question 54

Principle of figure-ground

Answer 54

figure is more "thing-like" and more memorable than the ground