Directional Selectivity and its Use in Early Visual Processing.
Abstract
The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero-crossings of Delta 2G(x,y)-I(x,y) are located, as in Marr & Hildreth (1979). In addition, the time derivative d/dt Delta 2G(x,y)-I(x,y) is measured at the zero-crossings, and serves to constraint the local direction of motion to within 180 degrees. The direction of motion is determined in a second stage by combining the local constraints. The second part of the paper suggests a specific model of the information processing carried out by the X and Y cells of the retina and the LGN, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1979
- Accession Number
- ADA078054
Entities
People
- D. Marr
- S. Ullman
Organizations
- Massachusetts Institute of Technology