Frontal theta and posterior alpha oscillations reflect the reactivation of working memory representations following interruptions

Abstract

Interruptions (secondary tasks) have been frequently investigated in behavioral studies leading to a deterioration of working memory performance. Yet, the underlying attentional control processes are not sufficiently understood. A lateralized working memory task was frequently interrupted by either a high- or low-demanding arithmetic task and a subsequent retroactive cue indicated the working memory item required for later report. We examined the role of frontal theta (4-7 Hz) and posterior alpha power (8-14 Hz) as correlates for retroactive attentional switches between working memory representations. In particular, highly demanding interruptions decreased primary task performance compared to a control condition without interruption. This was also reflected in decreased frontal theta power and higher posterior alpha power after retro-cue presentation, suggesting decreased attentional control resources. Moreover, reduced alpha lateralization indicated an impaired refocusing on primary task information following the interruption. These results highlight oscillatory mechanisms required for successfully handling the detrimental effects of interruptions.