Visual Processing of Object Velocity and Acceleration
Abstract
Several models of human motion discrimination have been proposed over the last decade. All are loosely related to the correlator approach originally used by Hassenstein and Reichardt to describe motion discrimination in insect eyes. These correlator models use simple spatial and temporal filtering followed by a non-linear multiplicative operation to account for human direction discrimination of sinusoidal stimuli near contrast threshold. Nevertheless, these models are extremely limited in scope. Research in this laboratory has shown that the correlator models cannot explain human speed discrimination even for sinusoidal targets. Apparently, a higher order network formed by combining local 'motion energy units' is required to encode speed. This laboratory has also studied how different features (object components) are combined so that complicated objects move at a uniform velocity. The combination rules are fairly arbitrary, but are limited by physical constraints. Basically, features with similar contrasts, wavelengths, spatial frequencies and temporal frequencies are combined to form a coherent whole moving at a single perceived velocity. Dissimilar features move independently. (aw)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 14, 1989
- Accession Number
- ADA216509
Entities
People
- Shawn Mckee