An architectural hypothesis for direction selectivity in the visual cortex: the role of spatially asymmetric intracortical inhibition.
Within a linear field approach, an architectural model for simple cell direction selectivity in the visual cortex is proposed. The origin of direction selectivity is related to recurrent intracortical interactions with a spatially asymmetric character along the axis of stimulus motion. No explicit asymmetric temporal mechanisms are introduced or adopted. The analytical investigation of network behavior, carried out under the assumption of a linear superposition of geniculate and intracortical contributions, shows that motion sensitivity of the resulting receptive fields emerges as a dynamic property of the cortical network without any feed-forward direction selectivity bias. A detailed analysis of the effects of the architectural characteristics of the cortical network on directionality and velocity-response curves was conducted by systematically varying the model's parameters.
Sabatini
S P
SP
Department of Biophysical and Electronic Engineering, University of Genoa, Italy. silvio@dibe.unige.it
Solari
F
F
D000818:Animals; D003491:Cybernetics; D008959:Models, Neurological; D009039:Motion Perception / Q000502:physiology; D009415:Nerve Net / Q000502:physiology; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology