Lecture 9: Parallel Processing

Isoluminant gratings are thought to be detected by:

parvo cells

With regard to LGN magno cells, which is false?

strongly color opponent

Parvo cells constitute about what percentage of ganglion cells?

70%

For a color opponent parvo neuron that is R+ in the center and G− in the surround, which stimulus causes maximum excitation?

a red spot surrounded by a black annulus

An on-center magno neuron is least responsive to a:

isoluminant grating

A lesion in the parvocellular region of the LGN is expected to result in a reduction in:

d) both “b” and “c” are correct

In the frequency-doubling clinical test, what aspect of the stimulus appears to double as the temporal frequency increases?

spatial frequency

Neurons located in the most dorsal layer of the primate LGN manifest which of the following properties?

a) color opponent

Compared to magno cells, parvo cells transmit action potentials:

more slowly

Which of the following categories of cells manifests strong color opponency?

d) both “a” and “c” are correct

The neurons that constitute the parvo pathway:

c) manifest sustained responses