PSY280 - 1. Introduction

Question 1

Perceptual process

Answer 1

begins with stimulus + ends with conscious experiences of perceiving, recognizing + taking action

Question 2

Bottom up processing/database processing

Answer 2

processing based on stimuli reaching receptors
based on incoming data - info at sense organs
data-driven

Question 3

Top down processing/knowledge-based processing

Answer 3

knowledge-driven
high level of analysis, based on previous experience
processing based on knowledge

Question 4

Psychological approach

Answer 4

psychophysics, measures relationship between stimuli and behavioral response

Question 5

Physiological approach

Answer 5

measuring two relationships, relationship between stimuli and physiological responses and the relationship between physiological responses and behavioral responses

Question 6

Cognitive influences on perception

Answer 6

How knowledge, memories + expectations that people bring to situation influence their perceptions

Question 7

Principle of Representation

Answer 7

stimuli + responses created by stimuli transformed betw environmental stimulus + perception
light from the back, bounces off screen to our eyes, light is transformed by air, lighting conditions + anatomical structures of eye
projected to retina backward + upside down
change in info betw environmental stimuli + perception

Question 8

Principle of Representation

Answer 8

perception not based on direct contact with stimuli
representations built based on activity at receptors that get integrated into the nervous system
using sensory info to make representations of world

Question 9

Transduction

Answer 9

diff specialized neurons for every modality - take energy + turn it into electrical signals interpreted by your brain
transformation of one form of energy [light] to another form [electrical energy]

Question 10

neural processing

Answer 10

starts at retina - start to organize info in the retina

some specialized for processing colour, some for contrast, shape

Question 11

neural processing

Answer 11

gets more specific as passed through to the brain
ends up to the cortex eventually
Electrical signals enter vast interconnected network of neurons, first in retina + out back of eye and then in the brain

Question 12

neural processing

Answer 12

multiple routes with some signals traveling in opposite directions some signals becoming reduced + others being amplified
changes in signals that occur as they are transmitted through this maze of neurons
Electrical signals arrive at primary receiving area
Primary receiving area for vision occupies most of the occipital lobe
Frontal lobe receives signals from all the senses and plays an important role in perceptions that involve the coordination of info received through two or more senses

Question 13

Perception + Recognition

Answer 13

perception: organizing info, giving meaning
recognition: categorize stimuli

Question 14

Action

Answer 14

how perception influences action + vice versa
perception doesn’t always create behavioural response
Electrical signals are transformed into conscious experience: person perceives that tree [5] and recognizes it [step 6]
Visual form agnosia: inability to recognize objects
Action: which involves motor activities

Question 15

Perception

Answer 15

private experience, we can’t really know what they see
quelia (experience is different)
we are good at measuring our own perceptions
reliability in our measurements, consistency among our perceptual observations
data can scientifically validated

Question 16

psychophysics

Answer 16

physical stimulus - psychological response

dominated by psychophysics: relationship betw physical stimulus + psychological response

Question 17

psychophysics

Answer 17

physical component - wavelength
response - psychological component
how change in psychological response relates to physical change

Question 18

Linear Relationship

Answer 18

as intensity increases, magnitude increases at same rate

Question 19

Exponential Relationship

Answer 19

perception of magnitude increases slowly at beginning + exponentially later on

Question 20

Logarithmic Relationship

Answer 20

dramatic increase at lower intensity, but at high intensity hard to tell difference

Question 21

Intensity of Pressure vs. Pain

Answer 21

can tolerate pain to a certain point + jumps after the point of intolerable
at some point pain can be indicative of damage

Question 22

absolute threshold

Answer 22

minimum stimulus intensity necessary for a stimulus to be detected
Development of the nervous system is influenced by kinds of stimuli have experienced in the environment

Question 23

difference threshold

Answer 23

minimum difference that must exist between two stimuli before we can detect the difference

Question 24

magnitude estimation

Answer 24

relationship between stimulus intensity + perceived magnitude •“On a scale of 1 to 10, how bright is A?”

Question 25

Classical psychophysical Methods:

Answer 25

original methods used to measure relationship between stimuli and perception

Question 26

perception is never perfect

Answer 26

humans are not ideal observers there is uncertainty in perception system it tends to be curve absolute threshold in the middle, but it’s a fuzzy boundary at 50% yes - follow line to intensity

Question 27

Gustav Fechner

Answer 27

described methods for absolute threshold linked perception to science ebbinghouse: adapted it to memory, lead to cognitive psychology

Question 28

method of limits

Answer 28

turn it down from top, start from bottom experimenter present stimuli in either ascending or descending order Threshold is determined by calculating the average of all crossover points

Question 29

method of adjustment

Answer 29

have participant control it themselves - continuous stimulus | stimulus intensity is either increase or decrease until the stimulus can just be detected

Question 30

method of constant stimuli

Answer 30

experimenter presents 5 to 9 stimuli with different intensities in random order Threshold is defined as the intensity that results in detection on 50% of the trials Method of constant some stimuli is most accurate method because it involves many observations + stimuli are presented in random order

Question 31

Difference threshold

Answer 31

the smaller the diff, the harder it is to detect, but it depends on the starting point

Question 32

Weber Fraction/Weber’s Law

Answer 32

weber percent is consistent Ratio DL/standard for lifting weights is 0.02 Difference threshold for weight is about 2%

Question 33

just noticeable difference (JND)

Answer 33

``` change in intensity between 25% “brighter” + 75% “brighter” (by convention). plotting percentage of times you are gonna say darker 50% is the reference point function of reference intensity ```

Question 34

Magnitude estimation

Answer 34

Experiment your present to standard stimulus + assigned value present lights at diff intensities + subject is asked to assign number to each of these lights proportional to the brightness of the original light

Question 35

Magnitude estimation

Answer 35

Brightness/perceived magnitude is a perceptual measure that indicates what observer experiences Response compression: increase in perceived magnitude is smaller than the increase in stimulus intensity

Question 36

Expansion

Answer 36

as intensity is increased, perceptual magnitude increases more than intensity Relationship between intensity of a stimulus in our perception follow same general equation of power functions

Question 37

Stevens’ power law

Answer 37

P = KS^n Perceived magnitude, P = constant, K x stimulus intensity, S raised to a power, n Exponents < 1 = response compression + > 1 = response expansion •n = exponent (slope of log)

Question 38

JND

Answer 38

higher intensity, jnd increases more because it is a percentage light intensity: dim light - little bit brighter, easy to notice bright light - has to be much brighter to tell the difference

Question 39

Weber’s Fraction

Answer 39

``` each type of sensory has diff weber fractions ∆I = k⋅I ∆I-JND k - WeberFraction I - referenceintensity ```

Question 40

magnitude estimation

Answer 40

linear, exponential (response expansion), logarithmic (response compression) compression: responses are compressed compared to intensity expansion: as intensity increases, perceptual magnitude increases much more

Question 41

power function

Answer 41

when you log each side the function is converted from non-linear to linear exponent is slope brightness: logarithmic function