Reconceptualizing the retrieval state as an internal attention state

Large-scale brain states or distributed patterns of brain activity modulate downstream processing and behavior. Sustained attention and memory retrieval states impact subsequent memory, yet how these states relate to one another is unclear. We hypothesize that the retrieval state reflects internal attention. The alternative is that the retrieval state reflects a controlled, episodic retrieval mode, specifically engaged when intentionally accessing events situated within a spatiotemporal context. To test our hypothesis, we developed a mnemonic state classifier independently trained to measure retrieval state evidence and applied this classifier to a spatial attention task. We find that retrieval state evidence increases during delay and response intervals when participants are maintaining spatial information. Critically, retrieval state evidence is positively related to the amount of maintained spatial location information and predicts target detection reaction times. Together, these findings strongly support the hypothesis that the retrieval state constitutes internal attention.