Neural dynamics of shifting attention between perception and working-memory contents

Abstract In everyday tasks, our focus of attention shifts seamlessly between contents in the sensory environment and internal memory representations. Yet, research has mainly considered external and internal attention in isolation. We used magnetoencephalography to compare the neural dynamics of shifting attention to visual contents within vs. between the external and internal domains. Participants performed a combined perception and working-memory task in which two sequential cues guided attention to upcoming (external) or memorised (internal) sensory information. Critically, the second cue could redirect attention to visual content within the same or alternative domain as the first cue. Multivariate decoding unveiled distinct patterns of human brain activity when shifting attention within vs. between domains. Brain activity distinguishing within- from between-domain shifts was broadly distributed and highly dynamic. Intriguingly, crossing domains did not invoke an additional stage prior to shifting. Alpha lateralisation, a canonical marker of shifting spatial attention, showed no delay when cues redirected attention to the same vs. alternative domain. Instead, evidence suggested that neural states associated with a given domain linger and influence subsequent shifts of attention within vs. between domains. Our findings provide the first insights into the neural dynamics that govern attentional shifts between perception and working memory. Significance Statement During almost every natural behaviour, our attention regularly shifts between sensory and memory contents. Although the systems and mechanisms of attentional control and modulation within the external and internal domains have been heavily studied in isolation, how attention crosses between these domains remains uncharted territory. Here, we provide the first study to investigate brain dynamics associated with shifting attention between contents in the sensory environment and memory representations. Using a novel experimental design, we isolated the patterns and dynamics of brain activity associated with shifting attention within vs. between the external and internal domains. Our findings reveal early, dynamic, and distributed patterns of activity that distinguish within- from between-domain shifts, offering fascinating initial insights, and opening new questions for investigation.