A continuous-time global theory of visual perception

Neurophysiological data show that visual neurons possess strong transient components. It is claimed that transient properties of early visual units are essential components in visual processing. Their function is clarified by analyzing the velocity-position tradeoff. Theoretical analysis shows that, for moving images, a recurrent on-center off-surround anatomy is required to sharpen the blurred output from the retina level. Properties of such positive feedback loops are studied for sustained inputs. It is proposed that a transient reset mechanism is required to control the sharpening properties of the network for dynamic images. These results lead to a global model where transient retinal cells rapidly and briefly reset extra-retinal loops. Transient components of sustained retinal cells control the dominance of feedforward over feedback signals to the extra-retinal cells.