Neuro Fns Lect #36

Front 1

This recieves input from the retinal ganglion cells and processes information from the contralateral visual hemifield?

Back 1

Lateral Geniculate Body

Front 2

A point of light in the contralateral visual field is represented in the LGB in (all or some) of the 6 layers in (horizontal or vertical ) register?

Back 2

All; Vertical

Front 3

True or False A retinotopic map is established in each layer of the LGB?

Back 3

True(

Front 4

Is there any convergence in the projection from the retina to the LGB?

Back 4

No (each retinal ganglion cell makes a one-one connection with a single neuron in the LGB)

Front 5

Layers 1,4,6 of the R LGB receive information from the (left temporal, left nasal, right temporal, right nasal)?

Back 5

Left Nasal

Front 6

How is incoming information to the LGB segregated?

Back 6

By eye (ipsilateral or contralateral) and by cell type (M-Cell and P-cell)

Front 7

Uncrossed fibers going to the LGB from the ipsilateral eye terminate onto which layers?

Back 7

2,3,5

Front 8

Information from the M-Cells terminates onto which layers of the LGB?

Back 8

1 and 2

Front 9

This pathway responds to visual signals by actional potential bursts as opposed to sustained increase in action potential frequency (magnocellular or parvocellular)?

Back 9

Magnocellular

Front 10

This pathway is color sensitive (magnocellular, parvocellular)?

Back 10

Parvocellular

Front 11

Visual acuity in this pathway is poor (magnocellular or parvocellular)?

Back 11

Magnocellular

Front 12

What kind of receptive fields do retinal ganglion cells have ?

Back 12

circular , concentric

Front 13

Is the receptive field of each LGB neuron identical to that of the single retinal ganglion cell that provides its input?

Back 13

Yes (remember no convergence….1:1)

Front 14

Where do the fibers from all 6 layers of the LGB project to?

Back 14

Primary visual cortex

Front 15

What is the location of the primary visual cortex?

Back 15

Upper and lower banks of the calcarine sulcus

Front 16

What layer of the primary visual cortex do axons of the LGB neurons terminate on?

Back 16

Layer 4

Front 17

Is there convergence of input from the LGB to neurons in layer 4 of the primary visual cortex?

Back 17

Yes

Front 18

What is the function of LGB to V1 projection?

Back 18

Maintains segregation of both location of eye (ipsilateral vs contralateral) and M,P pathways (different sub-layers)

Front 19

What is an Ocular Dominance Columns?

Back 19

An ODC is a vertical column that spans all six cortical layers and processes information predominantly from one eye

Front 20

How are ODCs arranged?

Back 20

left eye columns alternate with right eye columns

Front 21

A pair of adjacent left-right ODCs processes information from the (same, different) point in the (ipsilateral, contralateral) visual field?

Back 21

Same, contralateral

Front 22

Information from the upper part of the R visual field is processed by a pair of ODCs located where?

Back 22

L lower bank of the calcarine sulcus

Front 23

ODC is absent for these two representations?

Back 23

Blind spot of retina; Monocular temporal crescent of the contralateral visual field

Front 24

Neurons in layer 4 of V1 have (monocular or binocular) responses?

Back 24

Monocular (an ODC recives info from one eye)

Front 25

Where do layer 4 neurons of the primary visual cortex project to?

Back 25

Layers 2 and 3 above; Layers 5 and 6 below

Front 26

Which layers of the primary visual cortex are the initial regions for processing binocular features of vision?

Back 26

2,3,5,6

Front 27

Most of the input from neurons of the primary visual cortex found in layers 2,3,5,6 are come from (one eye, both eyes)?

Back 27

One eye (ocularly dominant still)

Front 28

These are smaller vertical slabs within an ODC in which all cells respond to stimuli with a preferred orientation?

Back 28

Orientation Columns

Front 29

These are pillar-like collections of cells in layers 2,3,5,6 of V1 that respond to the color of the stimulus and are insensitive to stimulus orientation?

Back 29

Blobs

Front 30

Input to neurons within blobs is exclusive for which pathway (M, or P)?

Back 30

P-pathway

Front 31

What are blobs assumed to be involved in (light sensitivity, color information, contrast)?

Back 31

Color information

Front 32

Which layers of the LGB terminate primarily on blobs?

Back 32

6-Mar

Front 33

What does a hypercolumn have?

Back 33

ODC for both eyes; 180 degree orientation columns for both eyes; Several Blobs

Front 34

Neurons of layer 4 of the primary visual cortex respond to (spots of light, bars/slits of light)?

Back 34

Bars and slits of light (because of convergence of several LGB)

Front 35

What are the various characteristics of the receptive fields located within Layer 4 of the primary visual cortex?

Back 35

On in center flanked by OFF; OFF in center flanked by ON; ON/OFF and vice versa; Orientation Specific

Front 36

Neurons in layers 2,3,5,6 of the primary visual cortex respond to a light bar under what conditions?

Back 36

Anywhere within the receptive field but ONLY with a required specific orientation

Front 37

Layers 2,3,5,6 do not have On/OFF specificity (true or false)?

Back 37

True(

Front 38

What pathway does the M-path take after layer 4 of the primary visual cortex?

Back 38

layer 4 > dorsal pathway > visual association cortex > Area V5 > Superior Parietal Cortex (SPC)

Front 39

What pathway does the P-path take after layer 4 of the primary visual cortex?

Back 39

Layer 4 > Ventral pathway > visual association cortex > area V4 > inferior temporal cortex (ITC)

Front 40

The function of this pathway (M or P) is motion detection, spatial and depth analysis, and visual attention?

Back 40

M pathway ("where" is it)

Front 41

The function of this pathway (M or P) is recognition of objects and faces, visual perception, memory, and color processing?

Back 41

P pathway

Front 42

lesions of the visual association areas cause defecits known as ?

Back 42

Visual Agnosias

Front 43

Is there a loss of visual acuity in visual agnosia?

Back 43

No

Front 44

What are the two factorsat work for perception of an object/person?

Back 44

Conscious visual perception; Linking to previous image (association)

Front 45

A patient looks at a picture of several small objects but only sees one of the figures, he most likely has (Prospopagnosia, achromatopsia, akinetopsia, simultanagnosia)

Back 45

Simultanagnosia

Front 46

Where are lesions in patients with simultanagnosia?

Back 46

bilaterally in the superior parietal cortex

Front 47

A patient comes in complaining that the world appears to not be moving, he has difficulty pouring water into a cup, he most likely has (Prospopagnosia, achromatopsia, akinetopsia, simultanagnosia)?

Back 47

Akinetopsia

Front 48

A patient comes in but does not recognize you, he looks at your awesome leather boots and then says, hello doctor, he most likely has (Prospopagnosia, achromatopsia, akinetopsia, simultanagnosia)?

Back 48

Prosopagnosia

Front 49

Where would you find lesions in people with prospagnosia?

Back 49

Bilateral inferior temporooccipital cortex (ventral P pathway)

Front 50

A patient states that everything in his right visual field appears to be black and white, his depth perception and spatial resolution are maintained, he most likely has (Prospopagnosia, achromatopsia, akinetopsia, simultanagnosia)?

Back 50

Achromatopsia (cortical color blindness)

Front 51

Which of these (Prospopagnosia, achromatopsia, akinetopsia, simultanagnosia) are lesions of the M pathway ?

Back 51

Simultanagnosia and Akinetopsia