Introduction to Perception

Question 1

what is sensation

Answer 1

a passive process bringing information from the outside world into the body and brain

Question 2

what is perception

Answer 2

an active process selecting, organising and interpreting the information brought to the brain by the senses

Question 3

sensory organs absorb…

Answer 3

energy from physical stimuli in environment

Question 4

sensory receptors convert this energy into…

Answer 4

neural impulses and send to brain

Question 5

what does the brain do with the neural impulses sent to it from sensory receptors

Answer 5

organises information and translates it into something meaningful

Question 6

describe the visual cliff experiment and what do the results suggest

Answer 6

Gibson & Walk (1960). infants placed on shallow size of table and encouraged to crawl over ‘visual cliff. 27/36 didn’t cross, suggesting that when healthy infants are able to crawl, they can perceive depth

Question 7

describe the visual cliff experiment with the importance of experience

Answer 7

Campos et al. (1981). infants with 11 days crawling experience tested in visual cliff task abut half crossed the deep size. 41 days less than a quarter crossed the deep side

Question 8

why do we study perception

Answer 8

to understand the world around us (survival). to design our environment effectively. to understand features of clinical disorders. curiosity.

Question 9

what are physical stimuli reduced to

Answer 9

electrical and chemical events

Question 10

in what way can perception not guarantee accurate representation of the physical world - what can alter it?

Answer 10

experience (visual illusions). brain damage (prosopagnosia). atypical development (sensory deprivation, ASD, DCD)

Question 11

give an example of perception being context specific

Answer 11

the ebbinghaus effect (orange dots being the same size but looking different sizes due to the size of the grey dots around them)

Question 12

give an example of the visual system not being passive

Answer 12

Kanizsa’s illusory square. it automatically extends line segments into parts of the drawing where they are missing. mind imagines that an object has been placed over the abstract shapes and lines in the drawing

Question 13

what does the perception of countless figures reflect?

Answer 13

properties of the way the visual system is wired

Question 14

what is the fundamental distinction in perceptual processing?

Answer 14

whether we achieve an understanding of the world through bottom up or top down processes

Question 15

what is top-down processing?

Answer 15

identification of objects using existing knowledge to guide processing of the sensory information

Question 16

what is bottom-up processing?

Answer 16

a representation of the object in view is gradually built up from visual image taken in by retina in the eye

Question 17

how does bottom-up processing work?

Answer 17

implicit or innate processes.

Question 18

how does top-down processing work?

Answer 18

knowledge, thoughts or expectations influence perception

Question 19

is bottom-up processing unique?

Answer 19

no - should be generic across species.

Question 20

is top-down processing unique?

Answer 20

yes - specific to the individual.

Question 21

what is bottom-up processing shaped by?

Answer 21

evolution

Question 22

what is top-down processing shaped by?

Answer 22

experience

Question 23

examples of same length lines looking different lengths

Answer 23

Muller-Lyer illusion (arrows) and Ponzo illusion (train tracks)

Question 24

perceiving one figure prevents you from…

Answer 24

perceiving the other

Question 25

to interpret a complex image, the brain has to identify…

Answer 25

a main figure, and relegate the rets of the image to the background

Question 26

describe the constructivist theory

Answer 26

Gregory (1970). top down there, construction of our world from past experiences alongside real-time visual info. info is lost by the time it reaches the brain. actively construct our perception of reality, the formulation of incorrect hypothesis lead to errors of perception

Question 27

describe the Gestalt theory

Answer 27

bottom up theory, starting from aspects of visual stimuli that influence perception and work its way up to higher-order cognitive processes. percepts determined by interaction of rules describing organisation. simplest interpretation favoured. whole is more than sum of its parts.

Question 28

what are the 5 other ‘Laws’ of Gestalt theory

Answer 28

proximity, similarity, closure, continuity, pragnanz

Question 29

describe the law of proximity

Answer 29

objects near to each other tend to be grouped together

Question 30

describe the law of similarity

Answer 30

items that are similar tend to be grouped together

Question 31

describe the law of closure

Answer 31

objects grouped together are seen as a whole

Question 32

describe the law of continuity

Answer 32

liens are seen as following the smoothest path

Question 33

describe the law of pragnanz

Answer 33

reality is organised or reduced to the simplest form possible

Question 34

describe the computational theory

Answer 34

Marr (1982). describes stages of processing required for a computer to see natural scenes. bottom up - views the initial retinal image as starting point of perception. how the brain turns info into accurate internal representations of our surrounding world.

Question 35

what is grey level description (computational theory)

Answer 35

intensity of light is measured at each point in retinal image

Question 36

what is primal sketch (computational theory)

Answer 36

raw sketch, areas potentially corresponding to edges and textures OR full sketch, these areas used to generate description of outline any objects in view

Question 37

what is 2D sketch (computational theory)

Answer 37

description is formed of how surfaces in view relate to one another and to the observer

Question 38

what is 3D object centred description (computational theory)

Answer 38

object descriptions produced allowing object to be recognised from any angle