Gueugneau Nicolas, Crognier Lionel, Papaxanthis Charalambos
INSERM/U887, Motricité et Plasticité, Université de Bourgogne, Dijon, France.
Brain Res. 2008 Jan 2;1187:95-102. doi: 10.1016/j.brainres.2007.10.042. Epub 2007 Oct 24.
The very close coordination between eye and hand indicates that eye movements are parts of the neural processes underlying the planning and control of arm movements. Eye movements are fundamental during observed actions and play a functional role in visual mental imagery. However, the role of eye movements during imagined actions is still unknown. Here, we report the timing features of eye and arm pointing movements for nine healthy participants in four conditions: Executed movements with orientation saccades (Eyes Free) or with no saccades (Eyes Motionless), and Imagined movements with Eyes Free or with Eyes Motionless. The first result was a facilitation effect of saccades upon both executed and imagined arm movements as revealed by the shorter arm movement durations in Eyes Free than in Eyes Motionless. Another interesting finding was that executed and imagined movements preserved their temporal similarities in both Eyes Free and Eyes Motionless, suggesting that the accuracy of motor representations is not dependent on the presence or lack of eye movements. This result and the close similarities between the EOG patterns accompanying both executed and imagined arm pointing movements in Eyes Free, argue in favour of a similar neurocognitive network in executed and imagined actions. We propose that internal forward models provide fine estimations of the temporal features of imagined arm movements, whatever they accompanied, or not, by orientation saccades.
眼睛和手部之间非常紧密的协调表明，眼球运动是手臂运动计划和控制背后神经过程的一部分。在观察到的动作中，眼球运动至关重要，并且在视觉心理意象中发挥功能性作用。然而，在想象动作过程中眼球运动的作用仍然未知。在这里，我们报告了九名健康参与者在四种条件下眼球和手臂指向运动的时间特征：有定向扫视（眼睛自由）或无扫视（眼睛静止）的执行动作，以及眼睛自由或眼睛静止的想象动作。第一个结果是，与眼睛静止相比，眼睛自由时手臂运动持续时间更短，这揭示了扫视对执行和想象的手臂运动都有促进作用。另一个有趣的发现是，在眼睛自由和眼睛静止两种情况下，执行和想象的动作都保持了它们的时间相似性，这表明运动表征的准确性并不取决于眼球运动的有无。这一结果以及眼睛自由时执行和想象的手臂指向运动所伴随的眼电图模式之间的密切相似性，支持了执行和想象动作中存在类似神经认知网络的观点。我们提出，无论是否伴有定向扫视，内部前向模型都能对想象的手臂运动的时间特征进行精细估计。
