Retinal ON/OFF model.

<p>A visual time-series stimulus (<i>I</i>(<i>t</i>)) was assigned to a certain receptive field of the retina. The retinal units (neurons) included in the receptive field, which have a biphasic temporal impulse response (TIR) function (<i>g</i>(<i>t</i>)), produced two types of time-series responses: ON- and OFF-type (<i>f^ON</i> (<i>t</i>) and <i>f^OFF</i>(<i>t</i>), respectively). These responses are assumed to be integrated at higher levels of the visual system.