Developmental and Cognitive Neuroscience Laboratory, Department of General Psychology, University of Padua, Italy.
Cereb Cortex. 2014 Feb;24(2):396-402. doi: 10.1093/cercor/bhs319. Epub 2012 Oct 9.
The focus of spatial attention can be not only oriented to a particular location, but also adjusted in its size to select visual information from a narrow (zoom-in) or broad (zoom-out) region of the visual field. Attentional orienting, saccades programming, and visual search have been linked to the frontal eye fields (FEF) activity. However, the FEF causal role in the frontoparietal network for the attentional focus size modulation remains unclear. Here, we delivered single-pulse transcranial magnetic stimulation (TMS) on FEF while participants performed an attentional zooming task. They were asked to detect a visual target appearing at 3 eccentricities from the fixation. Two cue types modulated the size of the attended region: a small cue was employed to narrow the attentional focus, whereas a large cue induced participants to broaden the attended region. Results showed that TMS delivered on the right FEF, but not on the left FEF, was able to interfere with both zoom-in and zoom-out attentional mechanisms. Our results provide the first evidence of the right FEF casual role in the attentional zooming control and give new insights into the neural mechanisms of dysfunctional spatial attention deployment shown in neurodevelopmental disorders, such as autism and dyslexia.
注意力的焦点不仅可以集中在特定的位置，还可以调整其大小，以从视野的狭窄（放大）或宽阔（缩小）区域选择视觉信息。注意定向、眼跳编程和视觉搜索与额眼运动区（FEF）活动有关。然而，FEF 在注意焦点大小调节的额顶网络中的因果作用尚不清楚。在这里，我们在参与者执行注意力缩放任务时对 FEF 施加单次经颅磁刺激（TMS）。他们被要求从注视点检测出现在 3 个离焦位置的视觉目标。两种提示类型调节了注意区域的大小：小提示用于缩小注意力焦点，而大提示则引导参与者扩大注意力区域。结果表明，施加于右侧 FEF 的 TMS 能够干扰内缩和外扩两种注意力机制，但施加于左侧 FEF 的 TMS 则不能。我们的研究结果首次证明了右侧 FEF 在注意力缩放控制中的因果作用，并为神经发育障碍（如自闭症和阅读障碍）中显示的空间注意力失调的神经机制提供了新的见解。
