Ph.D., Bar-Ilan University, Israel
Depth perception is the ability to reconstruct the visual 3-dimentional structure of the environment we live in and extract the information required to judge the relative distance of objects in the visual field. The faculty to sense depth is well rooted across the animal kingdom, as it is essential for navigation, orientation in space, objects detection, locomotion and many other essential behaviors. Some depth perception cues require binocularly vision (two eyes), while others can have ample information reaching from only one eye (monocular cues). Within the monocular depth clues only a single cue entails sufficient information do unambiguously judge the depth-sign (whether an object is near or far relative to the observer's fixation point). This cue is termed motion parallax (MP), which refers to the proportional changes in objects' motion direction and velocity while one moves through the physical world. Knowing the projection of a stimulus over the retina (retinal motion) is insufficient to disambiguate the depth-sign. For this to occur, additional information is required (for example: extra-retinal signal from pursuit eye movement). Recently it has been suggested that simulation of the global visual changes of eye rotation over time during observer translation in space (namely dynamic perspective cue, DP) can also elicit depth perception. The neural mechanisms involved in processing depth perception have only recently started to unveil. Recent electrophysiological studies found neurons in area MT that are sensitive to MP as does to DP. However little is known about the neuronal pathways of these cues. In the current study we investigate the behavioral and neural correlates of DP. In order to investigate the perceptual effect of DP we generated a discrimination task that incorporates a 3-D scene based on DP cue, which allows us to examine the effect of the stimuli parameters on humans' depth perception. More so, by implementing the same task with monkeys we can image the neural activity from early visual areas (V1,V2) using voltage sensitive dyes imaging (VSDI). This technique enables to measure the neuronal population response at high spatial and temporal resolutions. Applying such integrated approach offers a constructive method to study the functional correlates of depth perception and the linkage between perception and neuronal activity.