ORIENTATION-DEPENDENT BINOCULAR INTERACTIONS IN AREA 21A OF THE CAT

WE investigated binocular interactions in area 21a cells of the anaest hetized cat. Visual stimuli were drifting sinusoidal gratings presente d at the same optimal orientation in each eye (iso-oriented condition) or at the optimal orientation in the dominant eye and the orthogonal orientation in the other eye (orthogonal condition). In 68% of cells t he response in the binocular iso-oriented condition was greater than t he dominant eye monocular response, while in 88% of cells the response in the binocular orthogonal condition was less than the dominant eye monocular response. Our results suggest a possible role for this extra striate region of cortex in binocular contour rivalry.