Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University of Nijmegen, 6525 EN Nijmegen, the Netherlands.
Cereb Cortex. 2013 Apr;23(4):824-32. doi: 10.1093/cercor/bhs075. Epub 2012 Mar 27.
In order to execute a correct eye movement to a target in a search display, a saccade program toward the target element must be activated, while saccade programs toward distracting elements must be inhibited. The aim of the present study was to elucidate the role of the frontal eye fields (FEFs) in oculomotor competition. Functional magnetic resonance imaging-guided single-pulse transcranial magnetic stimulation (TMS) was administered over either the left FEF, the right FEF, or the vertex (control site) at 3 time intervals after target presentation, while subjects performed an oculomotor capture task. When TMS was applied over the FEF contralateral to the visual field where a target was presented, there was less interference of an ipsilateral distractor compared with FEF stimulation ipsilateral to the target's visual field or TMS over vertex. Furthermore, TMS over the FEFs decreased latencies of saccades to the contralateral visual field, irrespective of whether the saccade was directed to the target or to the distractor. These findings show that single-pulse TMS over the FEFs enhances the selection of a target in the contralateral visual field and decreases saccade latencies to the contralateral visual field.
为了在搜索显示中对目标执行正确的眼球运动，必须激活朝向目标元素的扫视程序，同时抑制朝向干扰元素的扫视程序。本研究的目的是阐明额眼区（FEF）在眼球运动竞争中的作用。在目标呈现后 3 个时间间隔内，对左 FEF、右 FEF 或顶点（对照部位）进行功能磁共振成像引导的单次脉冲经颅磁刺激（TMS），同时受试者执行眼球运动捕获任务。当 TMS 施加于与呈现目标的视野相对侧的 FEF 上时，与目标视野同侧的 FEF 刺激或顶点的 TMS 相比，同侧干扰物的干扰较小。此外，无论扫视是指向目标还是指向干扰物，FEF 上的 TMS 都会降低对侧视野的扫视潜伏期。这些发现表明，FEF 上的单次脉冲 TMS 增强了对侧视野中目标的选择，并降低了对侧视野中扫视的潜伏期。
