Departamento de Psicología Biológica y de la Salud, Facultad de Psicología, Universidad Autónoma de Madrid, Madrid, Spain.
Departamento de Neurociencia y Aprendizaje, Universidad Católica de Uruguay, Montevideo, Uruguay.
Psychophysiology. 2022 Sep;59(9):e14051. doi: 10.1111/psyp.14051. Epub 2022 Mar 23.
Alpha-band oscillations (8-14 Hz) are essential for attention and perception processes by facilitating the selection of relevant information. Directing visuospatial endogenous (voluntary) attention to a given location consistently results in a power suppression of alpha activity over occipito-parietal areas contralateral to the attended visual field. In contrast, the neural oscillatory dynamics underlying the involuntary capture of attention, or exogenous attention, are currently under debate. By exploiting the inherent capacity of emotionally salient visual stimuli to capture attention, we aimed to investigate whether exogenous attention is characterized by either a reduction or an increase in alpha-band activity. Electroencephalographic activity was recorded while participants completed a Posner visuospatial cueing task, in which a lateralized image with either positive, negative, or neutral emotional content competed with a target stimulus presented in the opposite hemifield. Compared with trials with no distractors, alpha power was reduced over occipital regions contralateral to distracting images. This reduction of alpha activity turned out to be functionally relevant, as it correlated with impaired behavioral performance on the ongoing task and was enhanced for distractors with negative valence. Taken together, our results demonstrate that visuospatial exogenous attention is characterized by a suppression of alpha-band activity contralateral to distractor location, similar to the oscillatory underpinnings of endogenous attention. Further, these results highlight the key role of exogenous attention as an adaptive mechanism for the efficient detection of biologically salient stimuli.
阿尔法波段振荡（8-14 Hz）对于注意和感知过程至关重要，通过促进相关信息的选择。将视空间内源性（自愿）注意力定向到给定位置会导致与注视视野相对侧的枕顶区域的阿尔法活动功率抑制。相比之下，目前对外源性注意（或外源性注意）的神经振荡动力学存在争议。通过利用情感突出视觉刺激的固有能力来吸引注意力，我们旨在研究外源性注意力是否表现为阿尔法波段活动的减少或增加。当参与者完成 Posner 视空间提示任务时记录了脑电图活动，在该任务中，具有正性、负性或中性情绪内容的侧化图像与在对侧视野呈现的目标刺激竞争。与没有干扰物的试验相比，对侧干扰图像的枕部区域的阿尔法功率降低。这种阿尔法活动的减少被证明是功能相关的，因为它与正在进行的任务中的行为表现受损相关，并且对于具有负效价的干扰物增强。总之，我们的结果表明，视空间外源性注意力的特征是对干扰物位置的阿尔法波段活动的抑制，类似于内源性注意力的振荡基础。此外，这些结果强调了外源性注意作为有效检测生物显著刺激的自适应机制的关键作用。
