White Robert L, Snyder Lawrence H
Department of Anatomy and Neurobiology, Box 8108, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63110, USA.
Exp Brain Res. 2007 Aug;181(3):477-92. doi: 10.1007/s00221-007-0947-7. Epub 2007 May 8.
The brain's sensitivity to self-generated movements is critical for behavior, and relies on accurate internal representations of movements that have been made. In the present study, we stimulated neurons below saccade threshold in the frontal eye fields of monkeys performing an oculomotor delayed response task. Stimulation during, but not before, the memory period caused small but consistent displacements of memory-guided saccade endpoints. This displacement was in the opposite direction of the saccade that was evoked by stronger stimulation at the same site, suggesting that weak stimulation induced an internal saccade signal without evoking an actual movement. Consistent with this idea, the stimulation effect was nearly absent on a task where an animal was trained to ignore self-generated eye movements. These findings support a role for the frontal eye fields in accounting for self-generated movements, and indicate that corollary discharge signals can be manipulated independent of motor output.
大脑对自身产生的运动的敏感性对行为至关重要，并且依赖于已做出运动的准确内部表征。在本研究中，我们在执行眼动延迟反应任务的猴子的额叶眼区刺激低于扫视阈值的神经元。在记忆期而非记忆期之前进行刺激，会导致记忆引导的扫视终点出现微小但一致的位移。这种位移与在同一位置更强刺激所诱发的扫视方向相反，表明弱刺激诱发了内部扫视信号而未引发实际运动。与此观点一致，在动物被训练忽略自身产生的眼球运动的任务中，刺激效应几乎不存在。这些发现支持了额叶眼区在解释自身产生的运动中所起的作用，并表明伴随放电信号可以独立于运动输出进行操纵。
