chapter 6 - visual perception

Question 1

sensation and perception

Answer 1

1. reception
2. transduction
3. transmission
4. selection
5. organisation
6. interpretation

Question 2

1. reception

Answer 2

light enters eye through cornea, then passes through the pupil. the lens focuses the light on the retina, which contains photoreceptors (rods and cones)

Question 3

2. transduction

Answer 3

the electromagnetic energy (light energy) is converted by rods and cones into electrochemical nerve impulses.

Question 4

3. transmission

Answer 4

rods and cones send the nerve impulses along the optic nerve to the primary visual cortex in the occipital lobes (back of brain), where receptor cells respond

Question 5

4. selection

Answer 5

image is broken up by feature detectors, so that we can pay attention to the important stimuli.

Question 6

5. organisation

Answer 6

when visual info reaches the brain, it is recognised so that we can make sense of it by using perceptual principles. once reassembled, it travels along two pathways simultaneously, to temporal lobe and parietal lobe.

Question 7

6. interpretation

Answer 7

visual stimulus is given meaning. the temporal lobes identify what the object is by comparing incoming info with info already stored in memory.

Question 8

perceptual constancies

Answer 8

enable us to maintain a stable perception of a stimulus, although image on retina may change.
size - we maintain a constant perception of an object’s size, even if the size on the retina alters.
shape - object is perceived to maintain its known shape despite the changing perspective from which it is observed.

Question 9

gestalt principles

Answer 9

• figure-ground organisation
• camouflage
• closure
• similarity
• proximity

Question 10

closure

Answer 10

we perceive an object as being whole, despite it being incomplete.

Question 11

proximity

Answer 11

the individual parts of a stimulus pattern are close to each other, we tend to group them together as a meaningful ‘whole’.

Question 12

camouflage

Answer 12

where figure-ground is used to ‘blend’ the contour of the figure against the ground, making the figure more difficult to see.

Question 13

figure-ground organisation

Answer 13

organising the part of the visual field which we focus on, the figure, and the background, the ground, by an imagined contour.

Question 14

similarity

Answer 14

an individual parts of a stimulus pattern are similar, we tend to group them together as a ‘whole’

Question 15

depth perception

Answer 15

ability to accurately judge 3D space and distance, using cues in the environment.

Question 16

binocular depth cues (two eyes)

Answer 16

retinal disparity: as our eyes are separated, each eye receives a slightly different image on the retina.
convergence: as an object comes closer to us, our eyes turn inwards to keep the object centred on the retina.

Question 17

monocular depth cues (one eye)

Answer 17

accommodation: lens of the eye changing shape so that it can focus light rays onto the retina.

Question 18

pictorial depth cues

Answer 18

• linear perspective
• interposition
• texture gradient
• relative size
• height in the visual field

Question 19

linear perspective

Answer 19

parallel lines are made to converge as they extend along the page to an imaginary point.

Question 20

texture gradient

Answer 20

used to make surfaces in a picture appear to recede into the distance (less and less detail as an image is more distant)

Question 21

interposition

Answer 21

is based on the partial blocking or obscuring of one object by another, the obstructed object appears to be further away.

Question 22

relative size

Answer 22

based on our tendency to perceive the object producing the largest retinal image as being nearest.

Question 23

height in the visual field

Answer 23

shows depth by portraying object further away as being closer to the horizon.

Question 24

perceptual set

Answer 24

a predisposition to perceive stimuli in a specific way.
can be affected by:
- emotion
- motivation
- context
- previous experience

Question 25

visual illusion

Answer 25

occurs when perception consistently differs from the objective reality.
types:
- ponzo illusion
- muller-lyer illusion
- amens room illusion

Question 26

visual perception`

Answer 26

how light from an object is cast as an image on the retina and nerve impulses travel to the brain where higher mental processes enable us to interpret what we see