Infer action and type of actor from biological motion
Types of Motion
Ego motion
Object motion
Apparent motion
Biological motion
Motion parallax
Components of Motion
Direction
Speed
Velocity
Computation of Visual Motion
Motion aftereffect
implies an opponent-process system, like that of colour vision
Interocular transfer
Result of activities of neurons in a part of the visual system
where information collected from two eyes is combined
Input from both eyes is combined in area V1
Recent studies: Locate site of motion aftereffects more precisely
Aperture
Correspondance problem
Aperture problem
Optic Flow
Models for Motion Detection
Spatiotemporal energy models for the perception of motion
Elaborated Reichardt detectors
Model of human visual-motion sensing
Eye Movement
Smooth pursuit
Saccade
problem of discriminating motion across the retina that is due to eye movements vs. object movements
Motor system solves “problem” of why an object in motion may appear
stationary by sending out two copies of each order to move eyes
One copy goes to eye muscles
Another (“efference copy”) goes to an area of visual
system that has been dubbed “comparator”
Comparator can then compensate for image changed caused by eye movement, inhibiting
any attempts by other parts of the visual system to interpret changes as object motion
Akinetopsia
caused by disruptions to the human cortical homolog of MT