6.2 The Neural Basis of Visual Perception Flashcards Preview

Behavioral Neuroscience > 6.2 The Neural Basis of Visual Perception > Flashcards

Flashcards in 6.2 The Neural Basis of Visual Perception Deck (24):
1

Receptive field

The part of the visual field to which any one neuron responds to

2

Lateral inhibition

The reduction of activity in one neuron by activity in neighboring neurons; The main function is to heighten the contrast at borders

3

Parvocellular neurons

Small cell bodies and small receptive fields; located mostly in or near the fovea; Well-suited to detect visual details; highly sensitive to color

4

Magnocellular neurons

Large cell bodies and receptive fields; distributed fairly evenly throughout the retina; Not color sensitive; respond strongly to moving stimuli and large overall patterns

5

Koniocellular neurons

The least numerous; the least responsive; and the least understood

6

Primary visual cortex

Area V1; striate cortex, because it's striped appearance; responsible for the first stage of visual processing; receives visual information from the lateral geniculate area; Responds to any kind of visual stimulus; active when people close their eyes and imagine visual stimuli

7

Secondary visual cortex

Area V2; conducts a second stage of visual processing; transmits the information to additional areas; can return information to V1

8

Ventral stream

Visual paths in the temporal cortex; "what" pathway; Specialized for identifying and recognizing objects

9

Dorsal stream

The visual path in the parietal cortex; "where" or "how" path; helps the motor system find objects and determine how to move toward them, grasp them, and so forth; sensitive to shape

10

Simple cells

Found exclusively in the primary visual cortex; the receptive field has fixed excitatory and inhibitory zones

11

Complex cells

Located in either area V1 or V2; have receptive fields that cannot be mapped into fixed excitatory and inhibitory zones; respond to a pattern of light in a particular orientation anywhere within its a large receptive field, regardless of the exact location of stimulus; Responds most strongly to a stimulus moving perpendicular to its axis

12

End-stopped or hypercomplex cells

Resemble complex cells with one additional feature: has a strong inhibitory area at one end of its bar-shaped receptive field; the cell responds to the bar-shaped pattern of light anywhere in its broad receptive field provided that the bar does not extend beyond a certain point

13

Feature detectors

Neurons whose responses indicate the presence of a particular feature

14

Inferior temporal cortex

Because cells in this area have huge receptive fields, always including the foveal field of vision, their responses provide almost no information about stimulus location; however, many of the cells do provide detailed information about stimulus shape

15

Shape constancy

The ability to recognize an object's shape even as it approaches or retreats or rotates

16

Visual agnosia

An inability to recognize objects despite otherwise satisfactory vision

17

Prosopagnosia

Ability to recognize other objects but not faces

18

Fusiform gyrus

Involved in the recognition of faces and complex visual stimuli

19

Blobs

A path of cells highly sensitive to color emerges in parts of area V1

20

Stereoscopic depth perception

The ability to detect depth by differences in what the two eyes see

21

MST

Medial superior temporal cortex; responds best to the expansion, contraction, or rotation of a large visual scene; Where cells respond whenever an object moves in a certain direction relative to its background

22

Motion blind

People are able to see objects but unable to determine whether they are moving or, if so, in which direction or how fast

23

Blindsight

The ability to localize visual objects within and apparently blind visual field

24

Lateral geniculate nucleus

A nucleus of the thalamus specialized for visual perception