Monocularly programmed human saccades during vergence changes?
1. When binocular fixation is shifted to a new target located at a different distance and in a different direction from initial fixation, a binocularly unbalanced saccade occurs at or near the onset of the composite eye movement. Those saccades typically produce good post-saccadic foveation of the target by one eye or the other. 2. Following such saccades, the better-aligned eye is typically as well aimed at the target as after pure versional saccades, but the partner eye deviates much more, thus requiring asymmetrical post-saccadic vergence movement. 3. This phenomenon suggests that during binocular viewing, the retinal eccentricity of a new-target's image from one of the eyes can be used to programme that eye's own saccade, so that it arrives reliably on target; and that the images of that target from both eyes participate in generating the saccadic excursion of the partner eye. 4. The ecologically useful result is rapid achievement of a high-resolution monocular view of the new target, although full binocular foveation is achieved much later.
Enright
J T
JT
Neurobiology Unit 0202, Scripps Institution of Oceanography, La Jolla, CA 92093, USA. jenright@ucsd.edu
D004292:Dominance, Cerebral / Q000502:physiology*; D005403:Fixation, Ocular / Q000502:physiology*; D007839:Functional Laterality; D006801:Humans; D008954:Models, Biological; D009949:Orientation; D012438:Saccades / Q000502:physiology*; D014741:Video Recording; D015348:Vision, Binocular / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology*