MT neurons combine visual motion with a smooth eye movement signal to code depth sign from motion parallax

摘要

The capacity to perceive depth is critical for an observer to interact with their surroundings. During observer movement, information about depth can be extracted from the resulting patterns of image motion on the retina (motion parallax). Without extra-retinal signals related to observer movement, however, depth sign (near vs. far) from motion parallax can be ambiguous. We previously demonstrated that MT neurons combine visual motion with extra-retinal signals to code depth sign from motion parallax in the absence of other depth cues. In that study, head translations were always accompanied by compensatory tracking eye movements, allowing for at least two potential sources of extra-retinal input. We now show that smooth eye movement signals provide the critical extra-retinal input to MT neurons for computing depth sign from motion parallax. Our findings demonstrate a powerful modulation of MT activity by eye movements, as predicted by human studies of depth perception from motion parallax.