Chap4 Flashcards
Acuity
Acuity = cycle / degree
Spatial frequency
The number of cycles of grading per unit of visual angle usually in degree
Retinal, ganglion cells and stripes
The response on the right of a ganglion cell to gratings of different frequencies on the left: low medium high
Phase
The phase of a grading refers to its position within the receptive field
What are the two lateral geniculate nuclei?
Where are the axons of the retinal ganglion cells synapse
Ipsilateral : the same side of the body or brain
Contralateral : the opposite side of the body or brain
Striate cortex
Primacy visual cortex, area 17, V1
Major transformation of visual information
Circular receptor feels in the retina, and LGN are replaced with elongated stripe receptor fields in cortex
M cell( magnicellular)
Motion contrast flicker
P cell ( parvocellular)
Form and color
Important features of striate cortex
Topographical mapping( dramatic, scaling, and affirmation from different parts of visual field)
Cortical magnification- the amount of cortex devoted to processing the phobia is proportionally much more than the amount of cortex devoted to the processing of the periphery
Visual acuity declines
In an orderly fashion with eccentricity distance from the fovea
Orientation tuning
Tendency of neurons in striate cortex to respond more to bars of certain orientations
How receptive fields are created in striate cortex
A cortical neuron that responds to oriented bars of light might receive and put from several retinal ganglion cells
If you string several retinal ganglion cells together, they can form an oriented bar
That is tune to any orientation you could be created in cortex by connecting it with the appropriate retinal ganglion cells
Other info
Eat LGN cell correspondence to one eye or the other, but never both
Each striate cortex cells can respond to input from both eyes
Cortical cells respond, especially to moving lines bars, grading directions of movement
Phase
The phase of one grading refers to a position within the receptive field
Hyper column
A 1 mm block of striate cortex containing “all the machinery “ to look after everything the visual correct is responsible for
