Cotti Julien, Panouilleres Muriel, Munoz Douglas P, Vercher Jean-Louis, Pélisson Denis, Guillaume Alain
CNRS/Université de la Méditerranée, Institut des Sciences du Mouvement UMR 6233, 163 av de Luminy, CP 910, 13288 Marseille, France.
J Physiol. 2009 Jan 15;587(1):127-38. doi: 10.1113/jphysiol.2008.159459. Epub 2008 Nov 17.
Sensorimotor adaptation restores and maintains the accuracy of goal-directed movements. It remains unclear whether these adaptive mechanisms modify actions by controlling peripheral premotor stages that send commands to the effectors and/or earlier processing stages involved in registration of target location. Here, we studied the effect of adaptation of saccadic eye movements, a well-established model of sensorimotor adaptation, in an antisaccade task. This task introduces a clear spatial dissociation between the actual target direction and the requested saccade direction because the correct movement direction is in the opposite direction from the target location. We used this requirement of a vector inversion to assess the level(s) of saccadic adaptation for two different types of adapted saccades. In two different experiments, we tested the transfer to antisaccades of the adaptation in one direction of reactive saccades to jumping targets and of scanning voluntary saccades within a target array. In the first experiment, we found that adaptation of reactive saccades transferred only to antisaccades in the adapted direction. In contrast, in the second experiment, adaptation of scanning voluntary saccades transferred to antisaccades in both the adapted and non-adapted directions. We conclude that adaptation of reactive saccades acts only downstream of the vector inversion required in the antisaccade task, whereas adaptation of voluntary saccades has a distributed influence, acting both upstream and downstream of vector inversion.
感觉运动适应可恢复并维持目标导向运动的准确性。目前尚不清楚这些适应性机制是通过控制向效应器发送指令的外周运动前阶段和/或参与目标位置登记的早期处理阶段来修改动作的。在这里，我们在一项反扫视任务中研究了扫视眼动适应（一种成熟的感觉运动适应模型）的效果。该任务在实际目标方向和所需扫视方向之间引入了明显的空间分离，因为正确的运动方向与目标位置方向相反。我们利用这种矢量反转的要求来评估两种不同类型适应性扫视的扫视适应水平。在两个不同的实验中，我们测试了对跳跃目标的反应性扫视在一个方向上的适应以及在目标阵列内扫描自愿性扫视的适应向反扫视的转移。在第一个实验中，我们发现反应性扫视的适应仅转移到适应方向的反扫视。相比之下，在第二个实验中，扫描自愿性扫视的适应转移到了适应和未适应方向的反扫视。我们得出结论，反应性扫视的适应仅在反扫视任务所需的矢量反转下游起作用，而自愿性扫视的适应具有分布式影响，在矢量反转的上游和下游均起作用。
