Visual System Part 2 Flashcards by Benjamin Ayala

Retinal ganglion cells axons leave the retina through ___________ and project to the _____________.

Optic nerve

Lateral geniculate nucleus (LGN)

How well did you know this?

Not at all

Perfectly

Axons from retinal ganglion cells in the _______________ remain on the same side of the brain and synapse on cells in the ____________(same side) LGN.

Temporal half

Ipsilateral

How well did you know this?

Not at all

Perfectly

While cells in the ________ half of the retina cross the midline and synapse on cells in the __________ (other side) LGN.

Nasal

Contralateral

How well did you know this?

Not at all

Perfectly

What axons are involved when you see an image on the left visual field?

Hint: What side of the eyeball is involved?

* same for the right visual field

Temporal side of the right eye

Nasal side on the left eye

How well did you know this?

Not at all

Perfectly

Information from the (left/right half) of the visual field from both eyes goes to the (left/right side) of the brain

While information from the (left/right) half of the visual field from both eyes goes to (left/right) half of the brain.

Information from the left half of the visual field from both eyes goes to the right side of the brain

While information from the right half of the visual field from both eyes goes to the left half of the brain.

How well did you know this?

Not at all

Perfectly

How is the information kept in the LGN?

In layers

How well did you know this?

Not at all

Perfectly

Different species have different exact numbers and arrangements of LGN layers. How many LGN layers does a human have?

___ receiving information from each eye.

6 layers

How well did you know this?

Not at all

Perfectly

True or False: The cells in the LGN have different receptive fields to those of the retinal ganglion cells (RBCs).

They both have center-surround receptive fields.

False

Receptive fields are very similar to the retinal ganglion cells

The second half is true.

How well did you know this?

Not at all

Perfectly

Looking at the figure

Which one of these receptive fields will stimulate the strongest action in the On-center ganglion cells?

The first one because the light shines in the middle of the ganglion cell,

which is similar to the Lateral Geniculate Nucleus receptive field

How well did you know this?

Not at all

Perfectly

Choose the best option

LGN cells receive (little/various) inputs from RGC

LGN’s receptive field is a bit (more/less) sophisticated

Various

How well did you know this?

Not at all

Perfectly

What are the various receptive fields that the LGN received?

Hint: There are three receptive fields.

Respond to different wavelengths of light

Broadband center-surround cells

Respond to specific wavelengths of light

Red/green color opponent center-surround cells

Blue color opponent cells

How well did you know this?

Not at all

Perfectly

_______________________ (Hint: one of the LGN receptive fields)

receive inputs from both red and green cones but are “color blind” and respond only to light-dark differences.

Broad-band center-surround cells

How well did you know this?

Not at all

Perfectly

Which LGN receptive field responds over a broad range of wavelengths?

Broad-band center-surround cells

How well did you know this?

Not at all

Perfectly

Answer these fellow examples of broad-band center-surround cells’ receptive fields. Here let’s focus on the on-center field.

If there is a central spot in the on-center field–> ______________.

If there is a peripheral spot in the off area –> _________________.

If there is a central illumination in the on-center field –> _______________.

If there is surround illumination in the off area –> ________________.

If there is a diffuse illumination –>___________________.

Look at image for answer

How well did you know this?

Not at all

Perfectly

Answer these fellow examples of broad-band center-surround cells’ receptive fields. Here let’s focus on the off-center field.

If there is a central spot in the off-center field–> ______________.

If there is a peripheral spot in the on area –> _________________.

If there is a central illumination in the off-center field –> _______________.

If there is surround illumination in the on area –> ________________.

If there is a diffuse illumination –>___________________.

How well did you know this?

Not at all

Perfectly

What are the three parallel pathways (the different types of ganglion cells and pathway to LGN) of the primate retinal ganglion cells?

Parvocellular

Magnocellular

Koniocellular

How well did you know this?

Not at all

Perfectly

True or False: These parallel pathways cross pathways and receive information from both eyes

False

Parallel pathways never cross pathways and receive information from left and right eye

How well did you know this?

Not at all

Perfectly

Choose the best option

Parvocellular parallel pathways

(Small/large) cells

(Small/Large) receptive fields

(Is/Not) Color sensitive

(sustained/transient) response ; (slowly/rapidly) adaptation

Signal (Form and Details/Motion)

Small cells

Small receptive fields

Is Color Sensitive

Sustained response; slowly adaptation

the signal form and detail

How well did you know this?

Not at all

Perfectly

Choose the best option

Magnocellular parallel pathways

(Small/large) cells

(Small/Large) receptive fields

(Is/Not) Color sensitive

(sustained/transient) response ; (slowly/rapidly) adaptation

Signal (Form and Details/Motion)

Large cells

Large receptive fields

NOT Color Sensitive

Transient response; rapidly adaptation

the signal Motion

How well did you know this?

Not at all

Perfectly

Choose the best option

Koniocellular parallel pathways

(Small/large) cells

(Is/Not) Color sensitive

Small cells

Don’t know if it color -sensnitive

How well did you know this?

Not at all

Perfectly

True or False: Different RGC types maintain sperate pathways through the lateral geniculate and visual cortex, while also respecting eye-specific pathways.

True

How well did you know this?

Not at all

Perfectly

In addition to having eye-specific LGN layers, primates also have _______ layers in LGN which receive input from different types of retinal ganglion cells.

Specific

What are the specific layers in the LGN?

(Hint: Similar to RGC)

Parvocellular

Magnocellular

Kohiocellular

What are the three different terms to describe the Koniocellar, parvocellular, and magnocellular RGC?

Koniocellar –> bisttratified

parvocellular –> midget

magnocellular –> parasol

Different RGC project to different LGN layers such that midget ganglion cells project to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. parsol ganglion cells project to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. bistraitifed ganglion cell project to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

parvocellular layers magnocellular layers ; konicoeullar layers

The arrangement of RGC to different LGN layers has been well characterized and linked to visual ___________ that remain anatomically separate LGN and into the primary visual cortex. (don't cross each other)

parallel pathways

# Choose the best option Magnocellular cells in LGN have (Small/Large) receptive fields (Yes/No) Color Blind cells Involved in processing \_\_\_\_\_\_\_\_\_.

Large Yes visual motion

# Choose the best option Parvocellular cells in LGN have (Small/Large) Receptive fields (Yes/No) Color-opponent in processing \_\_\_\_\_\_\_\_\_.

Small Yes Form visions

True or False: LGN cells axons project to the Contralateral (different side) primary visuals cortex (V1)

False LGN cells axons project to the **ipsilateral** (same side) primary visuals cortex (V1)

Where is the first place where the visual information from the two eyes comes together?

Primary visual cortex

What is the inter-ocular transfer?

Only occur at a cell receiving information from both eyes (binocular) this is seen in the primary visual cortex.

The flag color affects illusion (does/does not) show inter-ocular transfer.

Does not

The flag color effect illusion can be due to either ___________ that adapted or the __________ that adapted **but can not be due** to ___________ that adapted to this illusion. (inter-ocular transfer)

Retinal cells LGN cells Cortisol cells (in the primary visual cortex)

What is motion aftereffect illusion? After viewing a \_\_\_\_\_\_\_\_visual stimulus for a time with stationary eyes and then fixating a stationary stimulus. The stationary stimulus appears to move in the ________ direction to the original stimulus The cells which adapt to cause motion aftereffects illusion is at \_\_\_\_\_\_\_\_\_\_\_\_.

After viewing a **moving** visual stimulus for a time with stationary eyes and then fixating a stationary stimulus. The Stationary stimulus appears to move in the **opposite** direction to the original stimulus. The cells which adapt to cause motion aftereffect illusion is at **cortical neurons**.

Motion aftereffect illusion (does/does not) show inter-ocular transfer

Does

Cells in the primary visual cortex (do/do not) have center-surround receptive fields.

Do not

What does the primary visual cortex have instead of center-surround receptive fields?

They have elongated fields --\> respond best not to spots of light but rather to moving bars or edges oriented at a particular angle in the visual fields.

What are simple cells?

Simple cells, whose receptive fields are elongated are not center-surround but still have distinction and off areas in their receptive fields.

Simple cells respond best when a ________ at a vertical angle moves through the on a portion of its receptive field.

Light Bar

It is thought that simple cell receptive fields are constructed from ____________ by each cortical cells receiving inputs from several LGN cells whose receptive fields are aligned in space.

LGN inputs

Where are complex found?

Found in primary visual cortex

Complex cells also have ____________ but unlike simple cells they \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Orientation-specific repetitive fields do not have separate on and off areas.

Complex cells respond to either ______________ anywhere in their receptive fields

Light or dark edges

Complex cells are often sensitive to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Direction of motion of a moving bar

Complex cells receptive fields are thought to be constricted by each complex cell receiving inputs from _____________ with __________ but with overlapping on and off regions

Several simple cells Same orientation

True or False: Cells in the primary visual cortex are highly organized into maps, columns, and layers like cells in the somatosensory cortex.

True

There is a _______________ of visual space across the cortex.

Topographic map

There are ________ of the cortex, each with different inputs and outputs.

6 layers

There are ___________ --\> cell which response best to ispliateral side and contertateral side.

Ocular dominance columns

There are \_\_\_\_\_\_\_\_\_\_\_\_\_. Cells that respond to the same angle of stimulus are found in the same columns and orientation is mapped fairly smoothly across the surface of the cortex.

Orientation columns

What are blobs?

Special columns in the primary visual cortex which are cytochrome oxidase-positive contain color-sensitive cells which are poorly tuned for orientation

What do functional imaging studies reveal?

Reveal that, rather than simple rows or slabs of differing orientation preference, cells in our brain are arranged in pinwheels.

What is hypercolumn?

Containing both the **ocular dominance** and **orientation-selective columns** and color selective blobs (poorly tuned for orientation)

What is functional imaging?

Overlay of ocular dominance columns and pinwheels. Most orientation domains are split into ipsilateral and contralateral halves and thus serve the two eyes for that region of visual space.