Daniela Gresch^1,2, Dengxinyi Wei^2,3, Anna C. Nobre^2,4; ¹Ludwig Maximilian University of Munich, ²Yale University, ³University of Oxford, ⁴Wu Tsai Institute

During natural behavior, attention shifts seamlessly between information from the external sensory stream and internal representations held in memory. Only recently has research begun to investigate these dynamic shifts between external and internal attention using behavioral, eye-tracking, and electrophysiological measures. These studies have revealed behavioral differences accompanied by distinct neural patterns: differentiations between within- and between-domain shifts emerged early, evolved dynamically over time, and were broadly distributed across the scalp, suggesting the involvement of multiple processing stages within distributed networks as attention moves between perceptual and mnemonic domains. To determine which neural systems are recruited during such between-domain shifts, we conducted an event-related functional magnetic resonance imaging study using a recently developed task that combines perceptual and working-memory components. In this task, participants were presented with two consecutive cues, sequentially guiding attention to encoded contents, upcoming sensory input, or both. Crucially, the second cue could either shift spatial attention within the same domain (internal-to-internal or external-to-external) or shift spatial attention between domains (external-to-internal or internal-to-external). This design allowed for the systematic investigation of attentional shifts both within and between perception and working memory, as well as direct comparisons of the neural systems engaged in orienting external and internal attention. Consistent with previous work, both external and internal shifts of spatial attention activated dorsal frontoparietal regions, with internal shifts recruiting additional posterior parietal as well as lateral and medial prefrontal areas. Shifting attention between the perceptual and working-memory domains modulated brain activity more subtly, warranting further analysis to elucidate the specific contributions of individual brain regions during between-domain shifts.