Problem 6: Motion perception

Question 1

real motion vs illusory motion

Answer 1

real motion is when objects actually move, illusory motion is when we perceive something as moving when it actually is not moving

Question 2

apparent motion and induced motion

Answer 2

apparent: something is not moving but your perceive it as moving because two stimuli appear quickly after each other
induced: something appears to be moving because a large object behind it moves (moon and clouds)

Question 3

motion aftereffects

Answer 3

a moving stimulus causes stationary objects to appear to be moving (waterfall illusion)

Question 4

what is Reinhardt detector

Answer 4

a neural circuit consisting of 2 neurons.
-output unit: compares signals for 2 neurons and multiplies signals
- delay unit: delays signals of neuron A
the neuron will only fire if both signals reach the neuron at the same time, then movement will be perceived

Question 5

the corollary discharge theory

Answer 5

the theory uses 3 signals:
1 the image displacement signal (occurs when an image moves across retina)
2 the motor signal (which is sent from the brain to the eye and causes it to move
3 the corollary discharge signal (a copy of the motor signal)
movement wil be perceived if a brain part called the comparator receives just one signal, either the image displacement signal or the corollary discharge signal (ex. if a person scans the room the motor signal and the image displacement signal will arrive –> no movement perceived)

Question 6

experimental evidence for corollary discharge theory

Answer 6

monkey experiment: finding that there are neurons that only respond to objects that are actually moving

Question 7

akinetopsia

Answer 7

inability to perceive motion

Question 8

ecological approach to perception

Answer 8

focus on phenomena in natural context (perception in natural environment not lab)

Question 9

optic flow

Answer 9

movement of stationary objects as you move

Question 10

gradient flow

Answer 10

close objects move faster than distant objects

Question 11

focus of expansion

Answer 11

destination of where your body is going (no movement, point of direction)

Question 12

invariant information

Answer 12

information stays constant no matter how observer is moving

Question 13

reciprocal relation

Answer 13

body movements adjust based on vision, they have a reciprocal relationship

Question 14

affordances

Answer 14

information indicating how an object can be used

Question 15

swinging room experiment

Answer 15

walls move towards you: falling back to compensate
walls moves forward: fall forward
conflicting visual information form ears and muscles = sense of balance is tricked

Question 16

aperture problem

Answer 16

you do not see a corner, but a side of an object through a peephole, therefore you cannot see it moving. we search for corners to detect movement