Task interruptions impair visuospatial working memory: Behavioral and EEG evidence for feature-specific cognitive...

Working memory (WM) is vulnerable to interferences, especially from task interruptions that redirect the focus of attention to secondary tasks. Here, we used a visuospatial WM task to investigate how the modality and cognitive domain of interruptions affect performance. Twenty-eight participants memorized orientations of colored bars and reported one after a retrospective cue. During the maintenance phase, interrupting tasks varying in modality and cognitive domain occurred: visual arithmetic, auditory arithmetic, or visuospatial discrimination. Interruptions generally impaired memory performance, with the visuospatial discrimination task, which included low-level sensory feature overlap, causing the greatest decline. Further, target orientation's proximity to the horizontal axis was a good predictor in recall error, which showed a significant interaction only with visuospatial interruptions. EEG data showed reduced theta activity and weaker alpha/beta suppression to the retrospective cue following interruptions. After the visuospatial interruption, stronger posterior alpha asymmetries emerged, reflecting greater attentional demands for reorienting attention to the interrupted task. These results highlight that overlapping features between primary and interrupting tasks critically influence WM interference.