Term
| Where does visual information processing begin? What is processed there |
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Definition
In the retina
Retinal output form the retinal ganglion cells is processed |
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Term
What are the three types of retinal ganglion cells?
In what percentage are they represented in the retina? |
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Definition
M-type (5%)
P-type (90%)
nonM-nonP type (5%) |
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Term
| What are the main characteristics of M-type retinal ganglion cells? |
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Definition
Sense motion
Large receptive fields
Respond to transient stimuli
Not sensitive to wavelength |
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Term
| What are the main characteristics of P-type retinal ganglion cells? |
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Definition
Sensitive to shape, fine detail, and color
Small receptive fields
Responsive to sustained stimuli
Sensitive to wavelength |
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Term
| What are the main characteristics of nonM-nonP type retinal ganglion cells? |
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Definition
Sensitive to color
Sensitive to wavelength |
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Term
| Which nerve transfers information from the retina to the brain? |
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Definition
| Cranial nerve II/the optic nerve |
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Term
| What sort of axons are included in the optic nerve? What sort of information does the optic nerve carry? |
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Definition
Retinal ganglion cell axons (including M, P, and nonM-nonP cells)
Information from one retina (one nerve is on each side) including motion, form, and color |
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Term
| What is the optic chiasm? |
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Definition
| The place where optic axons are sorted. |
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Term
| What is contained in each optic tract? |
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Definition
*Axons from both eyes
*Information from one-half of the visual field |
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Term
| Where is the first central synapse in the central visual pathway? |
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Definition
| In the lateral geniculate nucleus (LGN) |
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Term
| True or false: the LGN processes information relayed from the optic nerve. |
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Definition
| False. The LGN only relays visual information from the retina to the brain. |
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Term
| Do retinal ganglion cells and lateral geniculate nucleus cells have similar or different response properties? |
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Definition
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Term
| Is the synapse between RGCs and LGNs excitatory or inhibitory? What is the neurotransmitter? |
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Definition
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Term
| What do magnocellular LGN neurons receive their input from? |
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Definition
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Term
| What properties do magnocellular LGN neurons respond to? |
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Definition
large center-surround fields (both on- and off- center)
transient responses
wavelength insensitive |
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Term
| What do parvocellular LGN neurons receive their input from |
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Definition
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Term
| Why type of visual information are Parvocellular LGN neurons responsive to? |
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Definition
*small center-surround receptive fields (both on-center and off-center)
*sustained firing
*some are wavelength sensitive |
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Term
| What do intralaminar (or koniocellular) LGN neurons get their input from? |
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Definition
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Term
| What are the response properties of intralaminar/koniocellular LGN neurons? |
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Definition
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Term
| Where do LGN neurons project to? |
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Definition
| Primary visual cortex (also known as V1 or striate or cortex) |
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Term
| Do LGN neurons process visual information? |
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Definition
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Term
| What neurotransmitter do LGN neurons release? Is the effect on post-synaptic cells excitatory of inhibitory? |
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Definition
*Release glutamate
*Effect on post-synaptic striate cortex cells is excitatory |
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Term
| What is the order of relay between the visual field and the brain? |
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Definition
Retina
Optic Nerve
Optic chiasm
Optic tract
LGN
Optic radiation
Primary visual cortex |
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Term
| How many major layers or lamina does the primary cortex have? |
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Definition
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Term
| How many layers is the fourth layer subdivided into, and what are their names? |
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Definition
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Term
| True or false: each type of LGN neurons has a specific target layer in the primary visual cortex. |
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Definition
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Term
| What layer of the primary visual cortex do intralaminar LGN neurons (color) target? |
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Definition
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Term
| What layer of the primary visual cortex do magnocellular LGN neurons (motion) target? |
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Definition
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Term
| What layer of the primary visual cortex do parvocellular LGN neurons (shape, color) target? |
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Definition
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Term
| What are the three distinct visual channels that the primary visual cortex has for visual information processing? |
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Definition
* motion (M channel)
* shape/form (P-IB channel [parvocellular interblob)
* color (Blob channel) |
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Term
| How can the function of the neurons in each of the visual channels of the primary visual cortex be determined? |
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Definition
by extracellular recording of the type of firing that occurs in response to visual stimulation. this includes:
1. the type of stimulus that is effective (response properties)
2. the location where stimulus is effective (receptive field) |
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Term
| Where do RGCs become myelinated? |
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Definition
| when they come together at the optic nerve |
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Term
| What layer do magnocellular LGNS project to after IValpha? |
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Definition
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Term
| What layer do parvocellular LGNs project to after IVCbeta? |
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Definition
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Term
| How are orientation selective cells in the M-channel arranged? |
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Definition
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Term
| What are simple cells in the M-channel |
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Definition
| monocular cells that have elongated receptive fields with oval-shaped on and off zones |
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Term
| What does the blob channel do? |
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Definition
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Term
| What does the P-IB channel do? |
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Definition
| Analyzes shape and fine detail |
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