Neural mechanisms of space vision in the parietal association cortex of the monkey.

Functional properties of visual and eye-movement-related neurons of area 7a were studied in alert behaving monkeys. Visual fixation (VF) neurons had selectivity in the direction and/or distance of gaze, signaling the spatial position. Visual tracking (VT) neurons had selectivity in the direction of movement, signaling the movement in space. Many passive visual (PV) neurons were suppressed during eye movement, discriminating real from "self-induced" movement. A group of PV neurons sensitive to the depth movement responded to the changing image size. A group of neurons sensitive to the rotation of visual stimulus in space were also found in area 7a.