Population Coding in Cat Visual Cortex Reveals Nonlinear Interactions as Predicted by a Neural Field Model

We develop population coding ideas toward a general approach to the analysis of cortical function that operationalizes the notion of cooperativity. Neural ensemble activation distributions (population representations) are constructed over a defined stimulus parameter space, in our case the 2-dimensional retinal position of the central visual field. In contrast to classical approaches using receptive field centered stimuli the method presented here requires the stimulation of a whole cell ensemble with an identical common stimulus. The constructed activation distribution allows a quantitative investigation of activation dynamics and cooperative effects, like lateral inhibition and excitatory interaction. We simulated the data with a continuous neural network model as proposed by Wilson & Cowan [14].