[Experimental and modeling study of orientation sensitivity of lateral geniculate nucleus neurons]

It was experimentally shown that orientation selectivity is characteristic of not only cortical but also dorsal lateral geniculate nucleus neurons in cats. With the help of mathematical modeling the factors that might influence the measurements of orientation selectivity are analyzed in the present work. Model responses on two types of stimuli, bars and brightness gradients, are qualitatively consistent with experimental data. It was shown that the non-zero orientation selectivity index may be caused by either the elongation of receptive field together with nonlinear saturation effects or the shift of the receptive field center relative to the stimulus center.