The University of Queensland, Queensland Brain Institute, St Lucia, QLD 4072, Australia.
The University of Queensland, School of Psychology, St Lucia 4072, Australia.
Neuroimage. 2017 May 15;152:171-183. doi: 10.1016/j.neuroimage.2017.03.008. Epub 2017 Mar 6.
Mechanisms of attention assign priority to sensory inputs on the basis of current task goals. Previous studies have shown that lateralized neural oscillations within the alpha (8-14Hz) range are associated with the voluntary allocation of attention to the contralateral visual field. It is currently unknown, however, whether similar oscillatory signatures instantiate the involuntary capture of spatial attention by goal-relevant stimulus properties. Here we investigated the roles of theta (4-8Hz), alpha, and beta (14-30Hz) oscillations in human goal-directed visual attention. Across two experiments, we had participants respond to a brief target of a particular color among heterogeneously colored distractors. Prior to target onset, we cued one location with a lateralized, non-predictive cue that was either target- or non-target-colored. During the behavioral task, we recorded brain activity using electroencephalography (EEG), with the aim of analyzing cue-elicited oscillatory activity. We found that theta oscillations lateralized in response to all cues, and this lateralization was stronger if the cue matched the target color. Alpha oscillations lateralized relatively later, and only in response to target-colored cues, consistent with the capture of spatial attention. Our findings suggest that stimulus induced changes in theta and alpha amplitude reflect task-based modulation of signals by feature-based and spatial attention, respectively.
注意机制根据当前任务目标为感觉输入分配优先级。先前的研究表明,在 alpha(8-14Hz)范围内的侧化神经振荡与将注意力自愿分配到对侧视野有关。然而,目前尚不清楚类似的振荡特征是否体现了目标相关刺激特性对空间注意力的非自愿捕获。在这里,我们研究了theta(4-8Hz)、alpha 和 beta(14-30Hz)振荡在人类目标导向视觉注意力中的作用。在两个实验中,我们让参与者在异质颜色的分心物中对特定颜色的短暂目标做出反应。在目标出现之前,我们用侧化的、非预测性的线索提示一个位置,该线索要么是目标色,要么是非目标色。在行为任务中,我们使用脑电图(EEG)记录大脑活动,目的是分析线索引起的振荡活动。我们发现,theta 振荡会对所有线索进行侧化,并且如果线索与目标颜色匹配,则这种侧化会更强。alpha 振荡侧化相对较晚,仅对目标色线索作出反应,与空间注意力的捕获一致。我们的发现表明,刺激引起的 theta 和 alpha 振幅变化反映了基于特征和空间注意力的任务对信号的调制。