Chapter 8: Motion perception

Week 8

motion

change in position over time

real motion

motion in the world created by

apparent motion

the appearance of real motion from a sequence of still images

correspondence problem 

how the visual system knows if an object seem at Time 1 is hte same as Time 2

induced motion

illusion

one moving object may cause another object to look like it’s moving

Reichardt detectors

neural circuits that enable the determination of direction and speed of motion by delaying input from one receptive field (to determine speed) to match the input of another receptive field (determine direction)

corollary discharge theory

feedback we get from our eye muscles as our eyes track an object is important to the perception of motion

Akinetopsia (motion blindness)

a rare condition in which an individual is unable to detect motion despite intact visual perception of stationary stimuli, caused by damage to area MT

motion aftereffect

stationary object is seen as moving in the opposite direction or real or apparent motion just observed

point light walker display

experiment

small lights are attached to the body of a person or animal, which is then filmed moving in a completely dark environment

affordance

information in the visual world that specifies how that information can be used

gradient of flow

difference in the perception of the speeds of objects moving past us in an optic flow display

focus of expansion

destination point in an optic flow display from which point perceived motion derives

Lateral Intraparietal area LIP

primate parietal cortex involved in the control of eye movements

medial intraparietal area MIP

posterior parietal lobe involved in the planning and control of reaching movements of the arms

anterior intraparietal lobe

posterior parietal lobe

act of grasping