Memorial Hospital of Carbondale, Carbondale, IL, USA.
Soc Cogn Affect Neurosci. 2011 Oct;6(5):639-45. doi: 10.1093/scan/nsq076. Epub 2010 Aug 11.
Spatial attention has been argued to be adaptive by enhancing the processing of visual stimuli within the 'spotlight of attention'. We previously reported that crude threat cues (backward masked fearful faces) facilitate spatial attention through a network of brain regions consisting of the amygdala, anterior cingulate and contralateral visual cortex. However, results from previous functional magnetic resonance imaging (fMRI) dot-probe studies have been inconclusive regarding a fearful face-elicited contralateral modulation of visual targets. Here, we tested the hypothesis that the capture of spatial attention by crude threat cues would facilitate processing of subsequently presented visual stimuli within the masked fearful face-elicited 'spotlight of attention' in the contralateral visual cortex. Participants performed a backward masked fearful face dot-probe task while brain activity was measured with fMRI. Masked fearful face left visual field trials enhanced activity for spatially congruent targets in the right superior occipital gyrus, fusiform gyrus and lateral occipital complex, while masked fearful face right visual field trials enhanced activity in the left middle occipital gyrus. These data indicate that crude threat elicited spatial attention enhances the processing of subsequent visual stimuli in contralateral occipital cortex, which may occur by lowering neural activation thresholds in this retinotopic location.
空间注意被认为是通过增强“注意焦点”内的视觉刺激的处理来适应的。我们之前的报告表明,粗略的威胁线索(掩蔽的恐惧面孔)通过包括杏仁核、前扣带和对侧视觉皮层的脑区网络促进空间注意。然而,之前的功能磁共振成像(fMRI)点探测研究的结果对于恐惧面孔引起的视觉目标的对侧调制没有定论。在这里,我们测试了这样一个假设,即粗略的威胁线索对空间注意的捕获将促进随后在掩蔽的恐惧面孔引起的“注意焦点”内呈现的视觉刺激的处理,该“注意焦点”位于对侧视觉皮层中。参与者在执行掩蔽的恐惧面孔点探测任务时,同时用 fMRI 测量大脑活动。掩蔽的恐惧面孔左视野试验增强了右顶叶上回、梭状回和外侧枕叶复合体中空间一致的目标的活动,而掩蔽的恐惧面孔右视野试验增强了左中枕叶的活动。这些数据表明,粗略的威胁引起的空间注意增强了对侧枕叶皮层中随后的视觉刺激的处理,这可能是通过降低该视网膜位置的神经激活阈值来实现的。