Fodor Zsuzsanna, Marosi Csilla, Tombor László, Csukly Gábor
Department of Psychiatry and Psychotherapy, Semmelweis University, Balassa utca 6, Budapest, 1083, Hungary.
Sci Rep. 2020 Nov 5;10(1):19179. doi: 10.1038/s41598-020-76190-3.
Focusing attention on relevant information while ignoring distracting stimuli is essential to the efficacy of working memory. Alpha- and theta-band oscillations have been linked to the inhibition of anticipated and attentionally avoidable distractors. However, the neurophysiological background of the rejection of task-irrelevant stimuli appearing in the focus of attention is not fully understood. We aimed to examine whether theta and alpha-band oscillations serve as an indicator of successful distractor rejection. Twenty-four students were enrolled in the study. 64-channel EEG was recorded during a modified Sternberg working memory task where weak and strong (salient) distractors were presented during the retention period. Event-related spectral perturbation in the alpha frequency band was significantly modulated by the saliency of the distracting stimuli, while theta oscillation was modulated by the need for cognitive control. Moreover, stronger alpha desynchronization to strong relative to weak distracting stimuli significantly increased the probability of mistakenly identifying the presented distractor as a member of the memory sequence. Therefore, our results suggest that alpha activity reflects the vulnerability of attention to distracting salient stimuli.
在工作记忆的有效性方面，将注意力集中在相关信息上同时忽略干扰性刺激至关重要。α波和θ波振荡与对预期的以及注意力可避免的干扰物的抑制有关。然而，对于出现在注意力焦点中的与任务无关的刺激的排除，其神经生理学背景尚未完全明确。我们旨在研究θ波和α波振荡是否可作为成功排除干扰物的指标。本研究招募了24名学生。在一项改良的斯特恩伯格工作记忆任务中记录64通道脑电图，在记忆保持期呈现弱干扰物和强（显著）干扰物。α频段的事件相关频谱微扰受到干扰性刺激显著性的显著调节，而θ波振荡则受到认知控制需求的调节。此外，相对于弱干扰物，对强干扰物更强的α波去同步化显著增加了将呈现的干扰物错误识别为记忆序列成员的概率。因此，我们的结果表明α波活动反映了注意力对显著干扰性刺激的易感性。
