Schafer Robert J, Moore Tirin
Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Neuron. 2007 Nov 8;56(3):541-51. doi: 10.1016/j.neuron.2007.09.029.
While the motor and attentional roles of the frontal eye field (FEF) are well documented, the relationship between them is unknown. We exploited the known influence of visual motion on the apparent positions of targets, and measured how this illusion affects saccadic eye movements during FEF microstimulation. Without microstimulation, saccades to a moving grating are biased in the direction of motion, consistent with the apparent position illusion. Here we show that microstimulation of spatially aligned FEF representations increases the influence of this illusion on saccades. Rather than simply impose a fixed-vector signal, subthreshold stimulation directed saccades away from the FEF movement field, and instead more strongly in the direction of visual motion. These results demonstrate that the attentional effects of FEF stimulation govern visually guided saccades, and suggest that the two roles of the FEF work together to select both the features of a target and the appropriate movement to foveate it.
虽然额叶眼区(FEF)的运动和注意力作用已有充分记录,但其二者之间的关系尚不清楚。我们利用视觉运动对目标视在位置的已知影响,并测量了这种错觉在FEF微刺激期间如何影响眼球的扫视运动。在没有微刺激的情况下,对移动光栅的扫视会偏向运动方向,这与视在位置错觉一致。在此我们表明,对空间对齐的FEF表征进行微刺激会增加这种错觉对扫视的影响。阈下刺激并非简单地施加固定矢量信号,而是将扫视引导至远离FEF运动场的方向,相反,在视觉运动方向上的引导作用更强。这些结果表明,FEF刺激的注意力效应控制着视觉引导的扫视运动,并表明FEF的这两种作用共同协作,以选择目标的特征以及对其进行中央凹注视的适当运动。