On-and-off center field cell activity: a conjecture about an integrated Processing

It is known that the retinal ganglion and LGB cells in the X system, and the simple cortical cells perform (at least in fIrst approximation) a linear algebraic spatial summation of the stimulus light distribution within their receptive fIelds (RF's). Hence the motivation for describing the cell output by means of a suitable two-dimensional correlation function. namely the one obtained through crosscorrelation of the visual input pattern with the function liescribing the RF. This communication presents a wide simulative experimentation on a digital computer by such a sinlple computational method, carried out in order to investigate the spatial filtering properties of neurones in the visual pathway. The results agree with neurophysiological data and psychophysical evidence, and give strength to the following conjecture. On- and off-center RF cell populations could cooperate to restore input images that have been blurred during acquisition because of relative motion between the image and the retina. Motion blurring effect should cause in fact a contrast reversal of the input within given spatial frequency ranges.