Module 03: Perception

Question 1

distal stimulus

Answer 1

real world objects to be perceived

Question 2

proximal stimulus

Answer 2

retinal image (upside down and backwards) of object, reception of info and its registration by sense organ

Question 3

percept

Answer 3

recognition of an object, meaningful interpretation of proximal stimulus

Question 4

form perception

Answer 4

segregation of while display into objects and background (think of reversible figures like the white vase and black faces)

Question 5

subjective contours

Answer 5

complex display to simplifying interpretations (think triangle example)

Question 6

what are the 5 principles of gestalt psychology and explain them

Answer 6

proximity – group things that are close together

similarity – grouping objects that look the same

connectedness/continuation – group objects whose contours form cts straight or curved line

closure – mentally fill gaps to complete picture

common fate – move together, group together

Question 7

law of pragnanz

Answer 7

out of all ways to interpret displays, tend to select the organization that yields the simplest and most stable shape and form

Question 8

bottom up processes

Answer 8

data driven

small bits of info from environment, combined to form percept

perception from info in distal stimulus

relatively uninfluenced from previous experience/learning

Question 9

what are some issues with bottom up processing

Answer 9

context effects: both accuracy and length of time needed to to recognize objects vary with context

expectation effects: similar to context effects but with expectations

bottom up processing can’t really explain this

Question 10

what are three examples of bottom up processing

Answer 10

template matching, feature analysis, prototype matching

Question 11

describe template matching

Answer 11

templates: previously stored patterns

an unknown incoming pattern is compared to all templates and identified by template that best matches it

the perceiver does not know what the object is until it is matched to a template

Question 12

what are some issues with template matching idea

Answer 12

need to have stored an impossibly large amount of templates

humans are capable of recognizing NEW objects

patterns recognized as more or less the same thing even when they differ a lot

Question 13

describe feature analysis

Answer 13

breaking down into features – using recognition of parts to infer the whole
(whole into parts)

feature not present => detectors do not respond as strongly

Question 14

what was Neisser’s visual search task and what were the findings

Answer 14

given an array of letters, participants respond if they detect a presence of a certain letter

took longer to find Z than Q in arrays with letters that look like Z and vice versa

(same with auditory things)

Question 15

what is selfridge’s pandemonium idea

Answer 15

‘demons’ are feature detectors

first level scans input, different feature demons scream louder when the feature is better matched

higher levels then scan output from lower levels

Question 16

what are some issues with the feature analysis idea

Answer 16

how do we define a feature?

how do we know what features to use to perceive the object?

list of possible features could be huge

Question 17

what is a protoype

Answer 17

idealized representation of some objects or events

Question 18

describe prototype matchiing

Answer 18

matching input to a prototype
ex. prototype of dog would be a very typical dog

stimulus could be an approximate match, more flexibility than templates

object is perceived when a match is found

takes into account object’s features AND the relationships between them

Question 19

top down processing

Answer 19

perceiver’s expectations, theories, or concepts guide the selection and combo of the info in the pattern recognition process

relies on expectation and knowledge/past leaning and context

Question 20

what are the three sketches of the jumbled vs regular kitchen scene

Answer 20

primal sketch – areas of brightness and darkness in 2D image and localized geometric structure - boundaries between areas

2.5D sketch – derives info about what surfaces are and how they are position in depth relative to viewpoint - relies on bottom up processes

3D sketch – recognition of objects and understanding the meaning of the scene (uses knowledge and specific expectations)

Question 21

what is change blindness

Answer 21

inability to detect changes to an object or scene

Question 22

what experiment studied change blindness

Answer 22

simons and levin

having a conversation, person walks through a door and replaced

goes unnoticed 50% of the time

visual percepts not precise copy of our visual world

Question 23

what is the word superiority effect

Answer 23

letters are easier to perceive in familiar context (words) than unfamiliar or no context

Question 24

study that looked at the word superiority effect

Answer 24

identify which 2 letters was briefly presented onscreen and was told the 2 choices the letter could be

sometimes displayed a word, or a random mix of letters

participants more accurately identified letters presented in the context of words

Question 25

what is the missing letter effect

Answer 25

attention is focused more on moderately familiar content words than highly familiar function words

ability to detect letters enhanced by word familiarity when words appear in isolation but inhibited by increased familiarity or role when a word appears in real text

Question 26

what is the connectionist model of word perception

Answer 26

input is processed at several different levels

each level of processing assumes to form a representation of info at different level of abstraction

lines between nodes represent connections (excitatory or inhibitory)
excitatory links, the two nodes suggest each other

perception of a word – activation of that word node also activates the nodes corresponding the the letters within that word

without word context, node for individual letter is less active so perception takes longer

Question 27

what is the neuroscientific perspective on word perception

Answer 27

words and pseudowords produce different PET scans from those produced when participants saw letter strings or false fonts

different brain areas active for different types of stimuli

PET activity in visual cortex of both hemispheres

Question 28

what is the constructivist approach to perception

Answer 28

people add to and distort info in proximal stimulus to obtain a percept

Question 29

what is direct perception

Answer 29

direct acquisition of info from the environment

perceive objects affordances: acts/behaviours permitted by objects, places and events

light hitting retina contains highly organized info that requires little to no interpretation

Question 30

what are the 2 types of visual agnosia

Answer 30

apperceptive agnosia

associative agnosia

Question 31

describe apperceptive agnosia

Answer 31

can process a limited amount of info

can see contours or outlines but have difficulties categorizing objects

some can’t name objects

associated with the right hemisphere

Question 32

describe associative agnosia

Answer 32

can match objects and copy drawings but do this very slowly and carefully

can be distracted by small details

cannot readily name the objects they have seen and drawn

correlated with bilateral damage to particular regions of brain in the cerebral hemisphere

Question 33

describe prosopagnosia

Answer 33

impaired explicit face recognition but preserved implicit face recognition

damage in the right hemisphere

Question 34

what is unilateral neglect

Answer 34

causes patient to virtually ignore stimuli on opposite side of damage

damage to the parietal cortex

Question 35

describe capgras syndrome

Answer 35

impaired implicit face recognition but preserved explicit face recognition

(no galvanic skin response, claims person is an imposter)