Target acceleration can be extracted and represented within the predictive drive to ocular pursuit.
نویسندگان
چکیده
Given sufficient exposure to stimulus presentation, the oculomotor system generates a representation of the stimulus characteristics, which is then used to predict the upcoming target motion. In addition to compensating for the perceptual-motor delay, these predictive processes perpetuate eye motion during a transient occlusion and compensate for the loss of visual input. At present, however, it is not well understood whether and how the oculomotor system extracts and represents target acceleration for subsequent predictive control. To this end, we used a target occlusion paradigm where both position and velocity of the target during the occlusion and at reappearance could not be predicted without extracting target acceleration before target disappearance. We found that the oculomotor response during the blanking period was not influenced by target acceleration when the initial exposure was 200 ms. However, smooth and saccadic eye movements did discriminate between the different levels of acceleration after an initial 500- or 800-ms exposure. In the event that the smooth response during the occlusion did not match well the target trajectory and thus eliminate a developing displacement error, there was an increased saccadic displacement. Still, the combined response during the blanking period did not eliminate retinal slip and position error at target reappearance. These results indicate that information on target acceleration can be extracted on-line, during pursuit of a visible ramp, and then used to drive a predictive oculomotor response in the absence of visual input.
منابع مشابه
Oculomotor hide and seek: pursuing an accelerating target behind an occluder. Focus on "target acceleration can be extracted and represented within the predictive drive to ocular pursuit".
Smooth pursuit eye movements are used to maintain the image of a moving object on the fovea. In the laboratory, most smooth pursuit studies are conducted with a target that travels at a constant velocity in clear view. In this situation, visual feedback created by the target’s motion on the retina allows the pursuit system to keep the fovea directed toward it. However, most objects moving in a ...
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The smooth pursuit eye movement system incorporates various control features enabling adaptation to specific tracking situations. In this work, we analyzed the interplay between two of these mechanisms: gain control and predictive pursuit. We tested human responses to high-frequency perturbations during step-ramp pursuit, as well as the pursuit of a periodically moving target. For the latter ta...
متن کامل3 of 32
Given sufficient exposure to stimulus presentation, the oculomotor system generates a representation of the stimulus characteristics, which is then used to predict the upcoming target motion. In addition to compensating for the perceptual-motor delay, these predictive processes perpetuate eye motion during a transient occlusion and compensate for the loss of visual input. At present, however, i...
متن کاملTRANSLATIONAL PHYSIOLOGY Predictive Smooth Ocular Pursuit During the Transient Disappearance of a Visual Target
Bennett, Simon J. and Graham R. Barnes. Predictive smooth ocular pursuit during the transient disappearance of a visual target. J Neurophysiol 92: 578–590, 2004. First published February 11, 2004; 10.1152/jn.01188.2003. When a moving target disappears and there is a complete absence of visual feedback signals, eye velocity decays rapidly but often recovers to previous levels if there is an expe...
متن کاملCross-axis adaptation of pursuit initiation in humans.
PURPOSE The initial acceleration of pursuit in the open-loop period is under adaptive control and undergoes motor learning. The current study was undertaken to examine the hypothesis that the direction of pursuit initiation can also be adaptively modified. METHODS Four neurologically and ophthalmologically normal subjects participated in the experiment. A modified step-ramp paradigm was used ...
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عنوان ژورنال:
- Journal of neurophysiology
دوره 98 3 شماره
صفحات -
تاریخ انتشار 2007