The strength of anticipated distractors shapes EEG alpha and theta oscillations in a Working Memory task.

Autor: Magosso E; Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi' (DEI), University of Bologna, Cesena Campus, Cesena, 47521, Italy; Alma Mater Research Institute for Human-Centered Artificial Intelligence, University of Bologna, Bologna, 40126, Italy. Electronic address: elisa.magosso@unibo.it., Borra D; Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi' (DEI), University of Bologna, Cesena Campus, Cesena, 47521, Italy.
Jazyk: angličtina
Zdroj: NeuroImage [Neuroimage] 2024 Oct 15; Vol. 300, pp. 120835. Date of Electronic Publication: 2024 Sep 07.
DOI: 10.1016/j.neuroimage.2024.120835
Abstrakt: Working Memory (WM) requires maintenance of task-relevant information and suppression of task-irrelevant/distracting information. Alpha and theta oscillations have been extensively investigated in relation to WM. However, studies that examine both theta and alpha bands in relation to distractors, encompassing not only power modulation but also connectivity modulation, remain scarce. Here, we depicted, at the EEG-source level, the increase in power and connectivity in theta and alpha bands induced by strong relative to weak distractors during a visual Sternberg-like WM task involving the encoding of verbal items. During retention, a strong or weak distractor was presented, predictable in time and nature. Analysis focused on the encoding and retention phases before distractor presentation. Theta and alpha power were computed in cortical regions of interest, and connectivity networks estimated via spectral Granger causality and synthetized using in/out degree indices. The following modulations were observed for strong vs. weak distractors. In theta band during encoding, the power in frontal regions increased, together with frontal-to-frontal and bottom-up occipital-to-temporal-to-frontal connectivity; even during retention, bottom-up theta connectivity increased. In alpha band during retention, but not during encoding, the power in temporal-occipital regions increased, together with top-down frontal-to-occipital and temporal-to-occipital connectivity. From our results, we postulate a proactive cooperation between theta and alpha mechanisms: the first would mediate enhancement of target representation both during encoding and retention, and the second would mediate increased inhibition of sensory areas during retention only, to suppress the processing of imminent distractor without interfering with the processing of ongoing target stimulus during encoding.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024. Published by Elsevier Inc.)
Databáze: MEDLINE
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