Flashcards in Striate Cortex (M2) Deck (23)
What type of processing occurs from complex cell wiring?
What is the pathway of neurons in the striae cortex for konio neurons?
konio to layer 2/3
For simple cells, what occurs if the slit of light covers a small part of the excitatory and inhibitory region (wrong orientation)?
Where does the LGN receive inhibitory input from (and what does this do)?
1. feedback inhibition from visual cortex
2. mesencephalic reticular formation (saccadic suppression)
3. inter-neurons within LGN (magno can inhibit parvo neurons)
What is different about complex striate cells compared to simple cells? 1. What is the same? 2
1. bar of light can stimulate the cell at many different locations within a relatively large receptive field
2. respond best to a bar of light of a given orientation
Throughout the cortical levels of the striae cortex, the columns of cells show what kind of sensitivity? 1. What do neighboring columns show? 2
1. same orientation sensitivity
2. a slight shift in orientation preference
What are the type of cells that respond best to a bar of light that moves through the receptive field in a certain direction and not at all in the opposite direction called?
directionally-selective complex cells
What are the most common cells in the striae cortex?
For simple cells, what occurs if the slit in the proper orientation but in the surround?
1. response of light OFF
2. could result in decrease in spontaneous activity while light ON
Why do simple cells show simpler behavior than complex cells?
they are closer in the circuit to the LGN input neurons
What are the type of cells that have an optimum length of stimulus in addition to orientation, position and sometimes direction of movement called?
Which layer of the striae cortex shows no orientation sensitivity? 1. Why? 2
1. layer 4
2. cells receive input from LGN neurons and have center-surround receptive fields
What is the pathway of neurons in the striae cortex for magno neurons?
1. magno to 4Cα
2. 4Cα to 4B
For simple cells, what occurs if the light covers all of the excitatory and inhibitory region (diffuse light)?
What are the cells in the striate cortex that have their receptive field elongated along a particular axis within an ON- or OFF-center and antagonistic surround?
Where is the first point in the visual pathway where info from OD and OS is combined? 1. So what processing info begins here? 2
1. striae cortex
2. binocular phenomenon like stereopsis
What is the relationship between orientation and ocular dominance columns in the striae cortex?
they run at a right angle to each other
What are the typical responses of the receptive fields for neurons in layers 4B and 2/3 of the striate cortex?
Which of the pathways is involved in color "blobs"?
If an electrode was inserted so that it traveled in a given cortical layer parallel to the surface, what is seen in terms of ocular dominance?
would cycle from OD dominance to OS dominance and back
Where do most LGN neurons project to? 1. What layer do most of the axons from the LGN project to? 2
1. striae cortex
2. layer 4C
What is the pathway of neurons in the striae cortex for parvo neurons?
1. parvo to 4Cβ
2. 4Cβ to 2/3