The neurons in areas 17, 18 and 19 of cat are local spatiotemporal operators which extract information about local motion and texture (among other things) from the retinal image. The long range goal of the proposed research is to understand exactly how this is done and to determine the underlying principles, mechanisms and connections which underlie this early visual processing. This proposal concentrates on a portion of the larger problem - namely, the emergence of selectivity for stimulus orientation and motion in simple cells of areas 17 and 18. The work is guided by three related models: (1) simple receptive fields in area 17 act as linear spatial filters of the Gabor form, (2) a new push-pull model of geniculo-simple convergence and (3) Adelson and Bergen's energy model of human motion perception. These ideas will be experimentally tested in areas 17 and 18 of anesthetized cats with the expectation that robust explanations of orientation and direction selectivity will result. It is likely that neural correlates of the early stages of the Adelson-Berger model will be found and that orientation selectivity in simple cells will be attributed to a differential input from populations of LGN cells in a way not previously evident.
| McLean, J; Raab, S; Palmer, L A (1994) Contribution of linear mechanisms to the specification of local motion by simple cells in areas 17 and 18 of the cat. Vis Neurosci 11:271-94 |
| McLean, J; Palmer, L A (1994) Organization of simple cell responses in the three-dimensional (3-D) frequency domain. Vis Neurosci 11:295-306 |
