Neural signatures of auditory distraction and cognitive demand during working memory performance

Abstract

Cognitive performance in real-world environments often requires maintaining working memory under simultaneous cognitive demand and environmental distraction. Although both factors have independently been associated with alterations in attention and executive control, their combined neural effects remain insufficiently understood. The present study investigated the influence of auditory distraction, time pressure, and their combination on working memory performance using a multidimensional electroencephalography (EEG) framework. Thirty healthy participants completed a working memory task under baseline, distraction, time-pressure, and combined conditions while EEG was recorded from 32 channels. Neural activity was characterized using oscillatory bandpower, topographical statistical mapping, hemispheric asymmetry, and weighted Phase Lag Index functional connectivity. Behavioral performance was complemented by subjective workload and stress assessments. Distraction was primarily characterized by widespread alpha-band suppression, significant frontal and parietal delta-band increases, and decreased frontal alpha asymmetry, whereas time pressure elicited frontal and parietal theta-band power increases. Rather than representing an additive superposition of both manipulations, the combined condition exhibited a distinct spatial pattern of oscillatory changes. Hemispheric asymmetry analyses revealed condition-dependent lateralization patterns that complemented conventional bandpower analyses. While alpha asymmetry primarily differentiated distraction, beta asymmetry emerged as the most consistent hemispheric marker across the experimental conditions showing regional beta-bandpower changes, highlighting the additional value of lateralized EEG measures for characterizing cognitive demands. Functional connectivity analyses did not reveal significant condition-dependent effects. These findings demonstrate distinct oscillatory signatures of distraction, time pressure, and their combination, highlighting the value of a multidimensional EEG framework for investigating concurrent cognitive demands.