Grover- Central Visual Function

Question 1

Retinal ganglion cells release ____ and excite their neuronal targets

Answer 1

Glutamate

Question 2

Part of hypothalamus involved w/ light entrainment of the internal circadian clock

Answer 2

Suprachiasmatic nucleus

Question 3

Area RGC’s synapse for stimulation of the pupillary light reflex

Answer 3

Pretectal area

Question 4

Involved in reflexie orienting movement of head and eyes

Answer 4

Superior colliculus

Question 5

Magnocellular (m-type) rgc’s are best suited for the detection of ?

Answer 5

Motion

Question 6

P type (parvocellular) RGC’s are best suited for ?

Answer 6

Detection of fine detail and colour

Question 7

Non-M Non-P RGC’s detect

Answer 7

Color

Question 8

LGN neurons release __ _as their nuerotransmitter and ____ the cells they synapse

Answer 8

Glutamate

Excite

Question 9

Axons of LGN neurons terminate in layer IVC of the primary visual cortex, synapsing onto _______

Answer 9

Stellate neurons

Question 10

The stellate neurons in layer IVC of the primary visual cortex, release ____ and excite ____

Answer 10

Glutamte.

Pyramidal neurons in other layers of cortex

Question 11

Layer II/III pyramidal neurons ( of primary visual cortex ) project to ?

Answer 11

Other cortical areas

Question 12

Layer V/ VI pyramidal neurons project to ?

This is talking about layers of the primary visual cortex

Answer 12

Subcortical areas

Question 13

Ocular dominance columns or stripes?

Answer 13

The LGN axons from layers IVCalpha and IVCbeta are organized to relay information specifically from either left or right eye to the cortical neurons in one column.

Question 14

Defined histologically by a high concentration of cytochrome oxidase

Answer 14

Blobs

Question 15

Layer IVCalpha cells are _____ selective

Answer 15

Orientation.

They respond best to stimuli presented in a specific orientation that is aligned with their “on” zone

Question 16

P-IB layer III neurons are relatively _ ____ to wavelength

Answer 16

Insensitive

Question 17

The high degree of orientation selectivity w/in the P-Ib channel allows for detection of ?

Answer 17

Form

Shape

Question 18

Blob channel neurons are the principle wavelength sensitive neurons of primary visual cortex and therefore have the primary function in the ____-

Answer 18

Detection of colour

Question 19

A small cube of cortex.

Contains a compete set of orientation columns, representing all possible 360 degrees.

Input from both eyes (complete set of ocular dominance columns)

All three info processing channels

Answer 19

Hypercolumn

Question 20

Neurons in area MT (which receives projections from area IV) are specialized for analysis of ______

Answer 20

Motion.

(Directionally selective
Large receptive field
Directional tuning
Organized in direction of motion columns )

Question 21

Lesions here are rare, but when they occur are associated w/ impaired perception of motion

Answer 21

Dorsal stream (including areas MT/MST)

Question 22

The ______ is formed by cortico-cortical projections from primary visual cortex. It is involved in the analysis of form and color

Answer 22

Area V4

Question 23

A rare condition caused by a lesion in area V4 of the ventral stream. There is partial or complete loss of colour vision despite normally functioning cones in the retina.
Pt’s describe the world as drab, existing only in shades of gray.

Answer 23

Achromatopsia

Question 24

Inferior temporal (IT) area, fed by V4. Contains major face recognition and a deficit here will cause prosopagnosia

Answer 24

Fusiform gyrus

Question 25

In children w/ strabismus (5% of kids), one eye’s input is suppressed to avoid dipolopia. If untreated, what will occur?

Answer 25

Permanent low acuity in the suppressed eye and poor depth perception.

Question 26

The critical period for vision in children?

Answer 26

Period when LGN axon terminals arborize the layer IV of the primary visual cortex.

Question 27

Correction of vision in children should be done _____ for the most effective recovery of normal visual function.

Answer 27

The first critical period.

Question 28

Visual cues for far-field depth perception

Answer 28

Size

Interposition (if one object is in front of the other)

Linear perspecitve (parallel lines converge)

Light and shadow

Motion parallax