Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Judgments of visual depth rely crucially on the relative binocular disparity between two visual features. While areas of ventral visual cortex contain neurons that signal the relative disparity between spatially adjacent visual features, the same tests in dorsal visual areas yield little evidence for relative disparity selectivity. We investigated the sensitivity of neurons in dorsal visual area V5/MT of macaque monkeys to relative disparity, using two superimposed, transparent planes composed of dots moving in opposite directions. The separation of the planes in depth specifies their relative disparity, while absolute disparity can be altered independently by changing the binocular depth of the two planes with respect to the monkey's fixation point. Many V5/MT neurons were tuned to relative disparity, independent of the absolute disparities of the individual planes. For the two plane stimulus, neuronal responses were often linearly related to responses to the absolute disparity of each component plane presented individually, but some aspects of relative disparity tuning were not explained by linear combination. Selectivity for relative disparity could not predict whether neuronal firing was related to the monkeys' perceptual reports of the rotation direction of structure-from-motion figures centered on the plane of fixation. In sum, V5/MT neurons are not just selective for absolute disparity, but also code for relative disparity between visual features. This selectivity may be important for segmentation and depth order of moving visual features, particularly the processing of three-dimensional information in scenes viewed by an actively moving observer.

Original publication

DOI

10.1523/JNEUROSCI.2658-11.2011

Type

Journal article

Journal

J Neurosci

Publication Date

07/12/2011

Volume

31

Pages

17892 - 17904

Keywords

Action Potentials, Analysis of Variance, Animals, Attention, Macaca mulatta, Male, Motion Perception, Neurons, Photic Stimulation, Vision Disparity, Visual Cortex