UCLA

Here we investigate visuomotor integration in humans, in particular, eye movements occurring during head and body movement. While this self-motion poses a challenge for the visual system it can also provide valuable information. This is evident in the first study, which demonstrates that self-motion-derived parallax can elicit binocular eye movements in depth (vergence). The most notable result of this study is that this depth cue drives vergence even when binocular disparities indicate a flat surface. The second study explores the dynamics of visual tracking behavior with the head free to move. Most studies of visual tracking have restrained the head, therefore little is known about the interaction between the eye movement systems involved when the head is also engaged in tracking. Using a rich visual stimulus and simultaneous tracking of the head and eye, we sought to close this gap in the literature. In particular, we were able to characterize not only the linear sensorimotor dynamics of smooth pursuit and head tracking during this task, but also the vestibular-ocular reflex as behaves during unrestrained pursuit. Sensorimotor integration is best understood in the context in which is has evolved to perform. Allowing the subject unrestrained self-motion is a step in that direction.