L5 spatial vision

Question 1

what tuning do visual system cells show?

Answer 1

orientation, size/width, spatial frequency constrast?

Question 2

how do spatial frequency and contrast interact?

Answer 2

higher and lower spatial frequencies require the most contrast (have least sensitivity) compared to middle frequencies. Lowest need the most.

Question 3

what are spatial frequency channels

Answer 3

bundles of neurons that are tuned to the same spatial frequency.

Question 4

contrast sensitivity function

Answer 4

areas of the image falling on different parts of the retina (fovea vs periphery) will be coded by different spatial frequency channels (highest i fovea)

Question 5

where is the retinal image processed?

Answer 5

V1 - unconcious

Question 6

where is the real world image formed

Answer 6

higher visual areas

Question 7

what are the retinal vs. real world properties

Answer 7

size and orientation constancy

Question 8

what are hybrid images

Answer 8

a low and high spatial frequency image are layered on top of one another - the high freq. image will be seen when image enlarged and low will be seen when image small

Question 9

resolution limit

Answer 9

the most detail we can see - the highest frequency we see before lines disappear - makes hard to see detail far away

Question 10

after effects are caused by

Answer 10

population coding and adaptation causing a peak shift and perceptual change

Question 11

how do we test for tuned cells in humans?

Answer 11

single cell recording in animals but unethical so psychophysical in humans