Smith Daniel T, Jackson Stephen R, Rorden Chris
School of Psychology, University of Nottingham, Nottingham NG7 2RD, UK.
Neuropsychologia. 2005;43(9):1288-96. doi: 10.1016/j.neuropsychologia.2004.12.003.
Humans are able to selectively attend to specific regions of space without moving their eyes. However, there is mounting evidence that these covert shifts of attention may employ many of the same brain regions involved when executing the eye movements. For example, functional magnetic resonance imaging (fMRI) studies show that the oculomotor region known as the frontal eye fields (FEF) are activated by the covert shifts of attention. However, it remains possible that the activations seen in these studies result from actively inhibiting eye movements rather than as a direct result of modulating perceptual processing. Here we provide direct evidence for the role of this region in endogenously driven spatial attention. We show that briefly disrupting the left FEFs with transcranial magnetic stimulation (TMS) eliminated the slow response times associated with the invalid strategic cues when the target appeared in the right visual field. At first glance, our findings appear incompatible with the results reported by Grosbras and Paus (Grosbras, M. -H., & Paus, T. (2002). Transcranial magnetic stimulation of the human frontal eye field: effects on visual perception and attention. Journal of Cognitive Neuroscience, 14(7), 1109--1120) and we suggest this is likely due to the design differences. Specifically, we disrupted the FEF at the time of cue onset, rather than target onset. Taken together with the findings of Grosbras and Paus, our findings suggest that the FEF plays an early role in the inhibition of perceptual information. Furthermore, our findings complement work by Ro et al. (Ro, T., Farne, F., & Chang, E. (2003). Inhibition of return and the frontal eye fields. Experimental Brain Research, 150, 290--296) who report that stimulation of the frontal eye fields disrupts the inhibitory consequences of reflexive attention shifts.
人类能够在不移动眼睛的情况下选择性地关注空间的特定区域。然而，越来越多的证据表明，这些注意力的隐蔽转移可能会用到许多与执行眼球运动时相同的脑区。例如，功能磁共振成像（fMRI）研究表明，被称为额叶眼区（FEF）的动眼神经区域会因注意力的隐蔽转移而被激活。然而，这些研究中观察到的激活情况仍有可能是由于积极抑制眼球运动所致，而非直接对感知处理进行调节的结果。在此，我们为该区域在内源性驱动的空间注意力中的作用提供了直接证据。我们发现，当目标出现在右侧视野时，用经颅磁刺激（TMS）短暂干扰左侧额叶眼区，消除了与无效策略线索相关的缓慢反应时间。乍一看，我们的研究结果似乎与格罗斯布拉斯和保斯报告的结果不一致（格罗斯布拉斯，M. -H.，& 保斯，T.（2002年）。人类额叶眼区的经颅磁刺激：对视觉感知和注意力的影响。《认知神经科学杂志》，14(7)，1109 - 1120），我们认为这可能是由于设计差异所致。具体而言，我们在线索出现时干扰额叶眼区，而非目标出现时。结合格罗斯布拉斯和保斯的研究结果，我们的研究结果表明额叶眼区在抑制感知信息方面发挥着早期作用。此外，我们的研究结果补充了罗等人的研究工作（罗，T.，法尔内，F.，& 张，E.（2003年）。返回抑制与额叶眼区。《实验脑研究》，150，290 - 296），他们报告说刺激额叶眼区会干扰反射性注意力转移的抑制后果。
