FA of Vision Terms

Question 1

Visual Angle

Answer 1

Size of retinal image in degrees

Question 2

Contrast Sensitivity Function

Answer 2

is the modulation transfer function of humans, describes the ability to preserve spatial frequency info after it has been encoded

Question 3

Tilt Aftereffect

Answer 3

adapting to tilted grating makes a vertical test grating seem tilted the other way, due to because feature detectors are slightly ambiguous, is a cortical mechanism not a retinal mechanism as effect exists even when eyes moving

eg. stare at a baseline vertical lines see that they are vertical, then stare at slightly tilted lines 10 degrees to the right and get your eyes adapted to this and tire out your neurons. Then stare back at the vertical lines from baseline and you will perceive them as being tilted 10 degrees to the left,

relate: feature detectors ambiguous, orientation is important we have a greater sensitivity to horizontal and vertical lines which could be due to how our environment heavily consists of vertical and horizontal lines

Question 4

Critical Period

Answer 4

exists for visual development, is a time during which particular visual experience is required to develop normal vision, during this period neurons in visual system exhibit plasticity as interconnections can be changed

we see diff critical period times for diff visual systems ie motion detection develops before face recognition, difference in timings for M and P pathways,

eg. Wiesel (1982) sewed kittens eyes shut some at birth and some later in life all for the same amount of time. With the at birth visual deprivation there was irreversible blindness to shapes and forms whereas this did not occur in the later in life visual deprivation. Shows that a critical period of forming visual connections exists