Visual-shift adaptation is composed of separable sensory and task-dependent effects
Visual-shift adaptation is composed of separable sensory and task-dependent effects
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DOI：
10.1152/jn.00290.2007
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发表时间：
2007-11-01
影响因子：
2.5
通讯作者：
Sabes, P. N.
中科院分区：
文献类型：
--
作者：
Simani, M. C.;McGuire, L. M. M.;Sabes, P. N.
视觉运动协调既需要来自不同感觉流的空间信息的精确对齐，也需要将这些感觉信号转换为精确的运动命令的能力。这两个过程都是高度可塑的，正如暴露于移位的视觉反馈后，目标导向运动的快速适应所说明的那样。虽然视觉转移适应是一种广泛使用的感觉运动学习模型，但多方面的适应反应通常难以量化。我们提出了一种定量表征适应的感官和任务依赖成分的方法。感官的后遗症是量化的“校准测试”，提供一个局部的，二维测量的感官重新校准。这些感官效果遵循一种精确的“可加性”形式，即视觉和右手之间的感官对齐变化等于视觉和左手之间以及右手和左手之间的变化向量之和。该可加性在暴露位置和第二泛化位置成立。这些结果支持感觉协调的组件转换模型，其中眼-手和手-手对齐依赖于一系列共享的感觉转换。我们还询问这些感觉效果与在目标到达和跟踪任务中测量的后效相比如何。我们发现，后效既取决于反馈移位暴露时所执行的任务，也取决于测试任务。结果表明，一般感觉重新校准和任务依赖的感觉运动效应都存在。任务依赖效应在高度刻板化的伸手动作中观察到，但在更可变的跟踪任务中没有观察到。
Visuomotor coordination requires both the accurate alignment of spatial information from different sensory streams and the ability to convert these sensory signals into accurate motor commands. Both of these processes are highly plastic, as illustrated by the rapid adaptation of goal-directed movements following exposure to shifted visual feedback. Although visual-shift adaptation is a widely used model of sensorimotor learning, the multifaceted adaptive response is typically poorly quantified. We present an approach to quantitatively characterizing both sensory and task-dependent components of adaptation. Sensory aftereffects are quantified with "alignment tests" that provide a localized, two-dimensional measure of sensory recalibration. These sensory effects obey a precise form of "additivity," in which the shift in sensory alignment between vision and the right hand is equal to the vector sum of the shifts between vision and the left hand and between the right and left hands. This additivity holds at the exposure location and at a second generalization location. These results support a component transformation model of sensory coordination, in which eye-hand and hand hand alignment relies on a sequence of shared sensory transformations. We also ask how these sensory effects compare with the aftereffects measured in target reaching and tracking tasks. We find that the aftereffect depends on both the task performed during feed-back-shift exposure and on the testing task. The results suggest the presence of both a general sensory recalibration and task-dependent sensorimotor effect. The task-dependent effect is observed in highly stereotyped reaching movements, but not in the more variable tracking task.