Saccade Adaptation Specific to Visual Context
Saccade Adaptation Specific to Visual Context
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DOI：
10.1152/jn.91076.2008
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发表时间：
2009-04-01
影响因子：
2.5
通讯作者：
Wallman, Josh
中科院分区：
文献类型：
--
作者：
Herman, James P.;Harwood, Mark R.;Wallman, Josh
赫尔曼JP，哈伍德MR，沃尔曼J。眼跳适应特定于视觉环境。神经生理学杂志101：1713-1721，2009年。首次发表于2009年1月21日; doi：10.1152/jn.91076.2008。当眼跳持续超过目标时，眼跳幅度逐渐减小，从而保持准确性。这种自适应过程被视为一种运动学习形式，可以应对由衰老或病理引起的眼睛及其肌肉的物理参数变化。人们不会期望这样的运动修复机制是特定于目标刺激的视觉特性的。我们让受试者对两个目标中的任何一个突然运动进行扫视-一个稳定照明的圆圈或一个闪烁的圆圈-其中一个在每次扫视期间都会后退，模拟超距离扫视的效果。扫视增益（扫视幅度/目标幅度）减少了15%的目标，后退与6%的目标，没有后退。每种类型的试验的连续块之间的增益的变化大部分发生在块的第一扫视，减少了0.12上的第一次试验的后退块和增加了0.1上的第一次试验的无后退块。两个目标的差分适应需要两种目标类型的后扫视反馈，如在单独的实验中所示，其中扫视到仅一个目标接收反馈，并且增益在两个目标类型之间没有差异。由视觉刺激定义的上下文可以作为在状态之间切换扫视增益的有效线索的这一证明表明，扫视适应可能具有迄今为止未被怀疑的适应性维度。
Herman JP, Harwood MR, Wallman J. Saccade adaptation specific to visual context. J Neurophysiol 101: 1713-1721, 2009. First published January 21, 2009; doi: 10.1152/jn.91076.2008. When saccades consistently overshoot their targets, saccade amplitudes gradually decrease, thereby maintaining accuracy. This adaptive process has been seen as a form of motor learning that copes with changes in physical parameters of the eye and its muscles, brought about by aging or pathology. One would not expect such a motor-repair mechanism to be specific to the visual properties of the target stimulus. We had subjects make saccades to sudden movements of either of two targets- a steadily illuminated circle or a flickering circle-one of which stepped back during each saccade it elicited, simulating the effect of a hypermetric saccade. Saccade gain (saccade amplitude/ target amplitude) decreased by 15% for the target that stepped back versus 6% for the target that did not step back. Most of the change in gain between successive blocks of trials of each type occurred on the first saccade of the block, decreasing by 0.12 on the first trial of a step-back block and increasing by 0.1 on the first trial of a no-step-back block. The differential adaptation of the two targets required postsaccadic feedback of both target types, as shown in a separate experiment, in which saccades to only one target received feedback, and the gain did not differ between the two target types. This demonstration that a context defined by a visual stimulus can serve as an effective cue for switching saccade gain between states suggests that saccade adaptation may have a heretofore unsuspected dimension of adaptability.