Chapter 2 - Basic processes in visual perception

Question 1

Retinal ganglion cells

Answer 1

Retinal cells provide the output signals from the retina

Question 2

Retinopy

Answer 2

The notion that there is mapping between the receptor cells in the retina and points on the surface of the visual cortex.

Question 3

Receptive field

Answer 3

The region of the retina in which light influences the activity of a particular neuron.

Question 4

Lateral inhibition

Answer 4

Reduction of activity in one neuron caused by activity in a neighbouring neuron.

Question 5

Achromatopsia

Answer 5

A condition caused by brain damage in which there is very limited colour perception but form and motion perception are relatively intact.

Question 6

Akinetopsia

Answer 6

A brain-damaged condition in which motion perception is severely impaired even though stationary objects are perceived reasonable well.

Question 7

Binding problem

Answer 7

The issue of integrating different types of information to produce coherent visual perception.

Question 8

Ventral stream

Answer 8

The part of the visual processing system involved in object perception and recognition and the formation of perceptual representations.

Question 9

Dorsal stream

Answer 9

The part of the visual processing system most involved in visually guided action.

Question 10

Allocentric coding

Answer 10

Visual or spatial coding of objects relative to each other.

Question 11

Egocentric coding

Answer 11

Visual or spatial coding dependent on the position of the observer’s body.

Question 12

Optic ataxia

Answer 12

A condition in which there are problems making visually guided movements in spite of reasonable intact visual perception.

Question 13

Visual form agnosia

Answer 13

A condition in which there are severe problems in shape perception (what an object is) but apparently reasonable ability to produce accurate visually guided actions.

Question 14

Hollow-face illusion

Answer 14

A concave face mask is misperceived as a normal face when viewed from several feet away.

Question 15

Proprioception

Answer 15

An individual’s awareness of the position and orientation of parts of their body.

Question 16

Dichromacy

Answer 16

A deficiency in colour vision in which one of three cone classes is missing.

Question 17

Negative afterimages

Answer 17

The illusory perception of the complementary colour to the one that has just been fixated; green is the complementary colour to red and blue is complementary to yellow.

Question 18

Colour constancy

Answer 18

The tendency for an object to be perceived as having the same colour under widely varying viewing conditions.

Question 19

Illuminant

Answer 19

A source of light illuminating a surface or object.

Question 20

Mutual illumination

Answer 20

The light reflected from the surface of an object impinges on the surface of a second object.

Question 21

Chromatic adaptation

Answer 21

Changes in visual sensitivity to colour stimuli when the illumination alters.

Question 22

Monocular cues

Answer 22

Cues to depth that can be used by one eye but can also be used by both eyes together.

Question 23

Binocular cues

Answer 23

Cues to depth that requires both eyes to be used together.

Question 24

Oculomotor cues

Answer 24

Cues to depth produced by muscular contractions of the muscles around the eye; use of such cues involves kinaesthesia (also known as the muscle sense).

Question 25

Texture gradient

Answer 25

The rate of change of texture density from the front to the back of a slanting object.

Question 26

Motion parallax

Answer 26

A depth cue based on movement in one part of the retinal image relative to another.

Question 27

Binocular disparity

Answer 27

A depth cue based on the slight disparity in the two retinal images when an observer views a scene; it is the basis for Stereopsis.

Question 28

Stereopsis

Answer 28

Depth perception based on the small discrepancy in the two retinal images when a visual scene is observed.

Question 29

Autostereogram

Answer 29

A complex two-dimensional image perceived as three-dimensional when not focused for a period of time.

Question 30

Amblyopia

Answer 30

A condition in which one eye sends an inadequate input to the visual cortex; informally known as lazy eye.

Question 31

Vergence

Answer 31

A cue to depth based on the inward focus of the eyes with close objects.

Question 32

Accommodation

Answer 32

A depth cue based on change in optical power produced by thickening of the eye’s lens when an observer focuses on close objects.

Question 33

Haptic

Answer 33

Relating to the sense of touch.

Question 34

Size constancy

Answer 34

Objects are perceived to have a given size regardless of the size of the retinal image.

Question 35

Ames room

Answer 35

A very distorted room that nevertheless looks normal under certain viewing conditions.

Question 36

Honi phenomenon

Answer 36

The typical apparent size changes when an individual walks along the rear wall of the Ames room are reduced when female observers view a man to whom they are very close emotionally.

Question 37

Open-object illusion

Answer 37

The misperception that objects with missing boundaries are larger than objects the same size with boundaries.

Question 38

Body size effect

Answer 38

An illusion in which misperception of one’s own bodily size causes the perceived size of objects to be misjudged.

Question 39

Subliminal perception

Answer 39

Perceptual processing occurring below the level of conscious awareness that can nevertheless influence behaviour.

Question 40

Blindsight

Answer 40

The ability to respond appropriately to visual stimuli in the absence of conscious visual experience in patients with damage to the primary visual cortex.