The responsiveness of Clare-Bishop neurons to motion cues for motion stereopsis

Under paralysis of eye movement and optical adjustment of visual axes of the two eyes, neuronal responsiveness in cat Clare-Bishop (CB) cortex to the binocular presentation of visual stimuli was studied using two types of visual stimulator which presented: 3-dimensional motion of a visual stimulus; and the motion cues (movement of retinal images in the two eyes) contained in the 3-dimensional motion. On the basis of the responsiveness to 3-dimensional motion presented by the first type of stimulator, the CB cells were classified into approaching (AP) cells which were selectively responsive to the approaching motion of a visual stimulus, recessive (RC) cells responsive to the recessive motion, frontoparallel (FP) cells responsive to the frontoparallel motion and non-selective (NS) cells responsive to more than two types of motion. The investigation of the CB cells with 2-dimensional motion stimulus demonstrated 3 different types of binocular interaction: facilitatory (52/239); antagonistic (33/239) or linear summation (154/239). Cells exhibiting the facilitatory interaction (n = 52) were all FP cells, those exhibiting the antagonistic interaction were either AP (n = 25) or RC cells (n = 8), and those exhibiting the linear summation were comprised of all varieties of cells (49 AP, 17 RC, 31 FP and 57 NS cells). The cells responsive to the approaching (37 AP cells) or recessive motion between the center of the receptive area and the nose (10 RC cells), or frontoparallel motion (42 FP cells) in the horizontal direction exhibited the selective responsiveness to the motion disparity (a combination of horizontal movement of retinal images in the two eyes), and those responsive to the vertically or obliquely deviating approaching (20 AP cells) or recessive motion (14 RC cells), or frontoparallel motion in the vertical or oblique directions (13 FP cells) exhibited that for a combination of the motion disparity and the frontoparallel motion in the vertical or oblique direction. These findings indicate that the CB cell responsiveness to 3-dimensional motion of a visual stimulus is explained by the binocular integration of motion signal viewed by each eye.