Chapter 8; Motion Perception Flashcards
motion aftereffect (MAE)
the illusion of motion of a stationary object that occurs after prolong exposure to a moving object.
apparent motion
illusion of motion when an object is followed by another in a different location.
correspondence problem
in motion detection, the problem faced by motion detection system of knowing which figure of frame 2 came from frame 1.
aperture problem
when moving object is viewed through an aperture, the direction of motion of a local feature or part of the object is ambiguous.
middle temporal area (MT)
part of brain in perception of motion.
interocular transfer
the transfer of an effect (adaptation) from 1 eye to the other
first-order motion
the motion of an object that is defined by changes in luminance.
second-order motion
motion of an object that is defined by changes in contrast or texture.
luminance-defined object
an object that is delineated by changes in reflected light.
texture-defined(contrast-defined) object
an object that is defined by changes in contrast or texture, but not luminance.
optic array
the collection of light rays that interact with objects in the world that are in front of a viewer
optic flow
changing angular position of points a perspective image that we experience as we move.
focus of expansion
the point in the center of the horizon from which, when we’re in motion (driven on the highway), all points in the perspective image seems to emanate. The focus of expansion is one aspect of optic flow.
biological motion
pattern of movement of animals
time to collision (TTC)
the time required for a moving object to hit a stationary object; distance/rate
smooth pursuit
a type of voluntary eye movement in which the eyes move smoothly to follow a moving object
microsaccade
involuntary, small jerk like eye movement.
vergence
type of eye movement which the two eyes move in opposite direction; both eyes looking at nose (convergence), etc.
saccade
type of eye movement, made both voluntarily and involuntarily, in which the eyes rapidly change fixation from one object/location to another.
reflexive eye movement
a movement of the eye that is automatic and involuntary.
saccadic suppression
reduction of visual sensitivity that occurs when we make saccadic eye movements. Saccadic suppression eliminates the smear from retinal image motion during eye movement.
comparator
An area of the visual system that receives 1 copy of command issued by the motion system when eyes move (other copy goes to the eye muscles). The comparator compares the image motion signal with the eye motion signal and can compensate for the image changes caused by the eye movement.
akinetopsia
rare neuropsychological disorder in which the affected person has no perception of motion.
