Purpose. The information processing principles subserved by early visual receptive field (RF) structure and organization remains undefined. Earlier work in spatial and color vision has demonstrated a role for concepts such as information maximization and principal components. But, in many situations, when taken separately, these approaches can lead to conflicting results. Of particular concern is the rather poor orientation tuning and correspondingly high RF correlation which can result when information flux is maximized. Here, we test the hypothesis that orientation selectivity in these models is improved by cortical interaction. Methods. The RFs of a simple visual system model were optimized to maximize the mutual information between model input and output subject to constraints on neural output power, synaptic strength, and connectivity. Excitatory and inhibitory cortical RF interaction could be introduced. Results. Both excitatory and inhibitory cortical RF interactions led to RFs with more refined orientation tuning properties. The extent of this refinement varies directly with information flux, and depends upon the extent to which synaptic resources are constrained. Conclusions. Cortical interactions can lead to considerable refinement in the quality of orientation tuning of the RF ensemble, However, from purely information processing considerations, the advantage to the organism of such refinement is unclear. The answer may lie with how early visual RF outputs are actually used by higher visual centers, or with the means by which the efficient RF ensemble is generated by the nervous system.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience