Chapter 1

Question 1

Steps in the perceptual process

Answer 1

1) stimulus in environment
2) light is reflected and transformed
3) receptor processes
4) neural processing
5) perception recognition action

Question 2

Principle of transformation

Answer 2

Stimuli and responses created by stimuli are transformed/changed between the environmental stimulus and perception (1st transformation occurs when light enters the eye, is focused by the optical system, and forms the image on the retina)

Question 3

Principle of representation

Answer 3

perception is based on representations of stimuli formed on receptors and on activity in the nervous system, not direct contact with stimuli

Question 4

Transduction

Answer 4

conversion of one form of energy into another, i.e. physical energy (light) into electrical signals (neural impulses)

Question 5

sensory receptors

Answer 5

cells specialized to respond to environmental energy

Question 6

visual pigment

Answer 6

visual receptors use light sensitive chemicals called visual pigments to transform light into electrical energy

Question 7

neural processing

Answer 7

network of neurons transmits/changes/processes signals from receptors to retina to brain to within the brain

Question 8

cerebral cortex

Answer 8

contains primary receiving areas for senses in:

• occipital lobe - vision
• temporal lobe - hearing
• parietal lobe - feeling/skin sensations
• frontal lobe - receives from all senses and helps to coordinate perception involving 2 or more senses

Question 9

perception

Answer 9

conscious awareness of stimulus (i.e. a tree)

Question 10

recognition

Answer 10

categorizing stimulus (i.e. naming stimulus “tree” to give meaning)

Question 11

visual field agnosia

Answer 11

Inability to recognize objects (i.e. Dr. P, the man who mistook his wife for a hat, could perceive some parts of object but could not organize/perceptually assemble these parts in a way that enabled him to recognize the object as a whole)

Question 12

action

Answer 12

motor activities

Question 13

knowledge

Answer 13

any information that the perceiver brings to a situation

Question 14

rat-man demonstration

Answer 14

shows how recently acquired knowledge influences perception

Question 15

bottom-up/data-based processing

Answer 15

processing based on incoming data/stimuli reaching the processors

Question 16

top-down/knowledge based processing

Answer 16

processing based on knowledge/ labelling a perception based on prior knowledge (not necessarily involved in perception of very small quick stimuli)

Question 17

psychophysical approach/psychophysics

Answer 17

measures relationship between stimuli and behaviour response

Question 18

oblique effect

Answer 18

better detail vision for vertical/horizontal lines compared to slanted lines

Question 19

physiological approach

Answer 19

measures relationship between stimuli and physiological responses and relationship of physiological and behavioural responses

Question 20

cognitive influences on perception

Answer 20

knowledge, memories, expectations brought to a situation that may influence perception

Question 21

absolute threshold

Answer 21

minimum stimulus intensity that can be detected

Question 22

classical psychophysical methods

Answer 22

3 main methods for measuring/determining thresholds by limits, adjustment and constant stimuli developed by Fechner (1860)

Question 23

Method of limits

Answer 23

classical psychophysical method - experimenter presents stimuli in increasing or decreasing order to find threshold - repeated multiple times from both top and bottom and results averaged

Question 24

Method of adjustment

Answer 24

classical psychophysical method - fastest - stimulus intensity +/- with a knob by observer until just detectable (done multiple times and results averaged)

Question 25

Method of constant stimuli

Answer 25

classical psychophysical method - experimenter presents 5-9 stimuli with different intensities in random order and observer replies "yes/no" (intensities are chosen so that lowest is never perceived and highest is always perceived). Threshold is determined by intensity perceived in 50% of trials (most accurate but time consuming)

Question 26

difference threshold (just noticeable difference)

Answer 26

Weber - minimum difference between two stimuli before we can perceive difference

Question 27

Weber's Law

Answer 27

Weber's law states that the just-noticeable difference between two stimuli is proportional to the magnitude of the stimuli, or, an increment is judged relative to the previous amount

Question 28

Weber Fraction

Answer 28

Generally the ration of difference threshold to the standard is constant (for weight it is 0.02) i.e. if 105 g can (only just) be distinguished from that of 100 g, the JND (or difference threshold) is 5 g, if the mass is doubled, the difference threshold also doubles (to 10 g), so that 210 g can be distinguished from 200 g

Question 29

magnitude estimation

Answer 29

experimenter presents standard/moderate stimuli and assigns it a value of 10, then presents other stimuli and observer assigns values proportionally

Question 30

response compression

Answer 30

increase in perceived magnitude is less than intensity (doubling the physical intensity of a stimulus less than doubles the subjective magnitude of the stimulus)

Question 31

response expansion

Answer 31

increase in perceived magnitude is greater than intensity (doubling the physical intensity of a stimulus more than doubles the subjective magnitude of the stimulus)

Question 32

Power functions

Answer 32

relationship between perceived intensity and magnitude - Steven's power law, P=KS^n where P=perceived, K= constant, S= stimulus intensity. n1.0= response expansions i.e. electric shock

Question 33

phenomenological method

Answer 33

a person describes what they are perceiving or indicates when a perticular perception occurs

Question 34

signal detection theory

Answer 34

detection of stimulus relies on both sensitivity and response criterion

Question 35

visual search

Answer 35

find one stimulus among many as quickly as possible

Question 36

reaction time

Answer 36

time between presentation of and reaction to a stimulus

Question 37

response criterion

Answer 37

if low threshold for response - more yes answers, if high threshold for response - more no answers

Question 38

hit

Answer 38

correct response - saying yes when a stimulus is present

Question 39

miss

Answer 39

incorrect response - saying no when a stimulus is present

Question 40

false alarm

Answer 40

incorrect response - saying yes when no stimulus is present

Question 41

correct rejection

Answer 41

correct response - saying no when no stimulus is present

Question 42

payoffs

Answer 42

inducements to answer a particular way in a signal detection experiment

Question 43

Receiver Operating Characteristic

Answer 43

a curve on a plot where subjects are tested using different payoff criteria to induce different levels of correct/incorrect answers. If participant answers lie on the curve at each criteria, it is clear that they have the same sensitivity.