Describe the basic pattern of the lateral geniculate nucleus of the thalamus

If you were to flatten it, it would be an orderly part-to-part map of the retinal inputs from half of the visual world. There are 6 layers: 1, 4 and 6 are from the contralateral eye (have been crossed over) and 2, 3 and 5 are from the ipsilateral eye (from the same side)

Size, distance, motion, shape and color are all issues that what part of the brain should care about?

The visual cortex

The (blank) pathway assesses spatial relations in the visual field and routes to the parietal lobe for further analysis. The (blank) pathway is responsible for object recognition and routes to the temporal lobe for memory

Dorsal, ventral

The (blank) stream of the unfolded visual cortex goes to the V4 section which determines the color and form of an object while the (blank) stream goes to the MT (middle temporal) section which determines movement and location

Ventral, dorsal

(Blank) neurons are present throughout layers 2, 3, 5 and 6 of the visual cortex while (blank) neurons are present in layer 4

Pyramidal, spiny stellate

What key function does layer 2/3 of the cortical layer system play?

It is responsible for intracortical projections

What key laminar function is layer 4 of the cortical layer system responsible for?

Receiving subcortical input from the LGN

What key laminar function do cortical layers 5/6 play?

They serve as cortical outputs (5 to the superior colliculus and 6 to the LGN)

The main (blank) of the basal ganglia and its structures is the cortex while its main (blank) are the thalamus andthe superior colliculus

Input, outputs

Muscle tone, regulation of posture and modifications of movement are the key functions of what part of the brain?

The basal ganglia and its associated structures

How do neurons in the V1 section of the visual cortex respond to bars of light positioned at different angles?

Each neuron has a preferred orientation at which it optimally responds while slightly different configurations will result in weaker responses in terms of AP frequency

How must electrodes that are designed to examine the orientation preferences of orientation columns be inserted through the cortex?

They must be inserted obliquely (in between layers); going straight through all of the layers in a vertical formation would result in a reading of all of the same orientation preferences

What is another term for the six layers that all serve as the basic functional unit of the visual cortex?

A cortical column

How do cells in layer 4B of the cortical column react to left-to-right and right-to-left motion?

They fire with very high intensity during left-to-right motion but much more lightly with right-to-left motion

The magnocellular layer of the LGN is made up of large cells which are fast, transient, motion-sensitive and color-insensitive which determine where an object is and how fast it is traveling. What layers of the LGN are they comprised of and to where do they project?

They make up the 1 and 2 layers and they project to the 4C-beta layer

Parvocellular cells are smaller, slower, sustained, color sensitive and are responsible for object recognition. What layer of the LGN do they make up and to where do they project?

They make up layers 3-6 and project to the 4C-beta layer

Koniocellular cells are interlaminar cells which transmit short-wavelength cone signals. Where do they project to in the cortical column?

They project to the bulbs of the 2/3 layer

These are patches of orientation-insensitive, color-sensitive pyramidal cells in the 2/3 layer of the cortical column

Blobs

What is important to note about the color-sensitive blobs that k-cells project to?

They are missing from layer 4 of the cortical column

The left visual field of humans is carried by the (blank) optic tract while the right visual field is carried by the (blank) optic tract

Right, left

What did Hubel, Wiesel and LeVay find in the 1970s when the injected radioactive amino acids into one eye?

They found that ocular dominance columns are eye-specific domains

Mixing of the pathways from the 2 eyes first occurs in the visual cortex after which layer?

4C