Colloquium - “How hippocampal memory shapes, and is shaped by, attention"

Abstract:  Attention modulates what we see and remember. Memory affects what we attend to and perceive. Despite this connection in behavior, little is known about the mechanisms that link attention and memory in the brain. One key structure that may be at the interface between attention and memory is the hippocampus. Here, I’ll explore the hypothesis that the relational representations of the hippocampus allow it to critically contribute to bidirectional interactions between attention and memory. First, I’ll show — in a series of human fMRI studies — that attention creates state-dependent patterns of activity in the hippocampus, and that these representations predict both online attentional behavior and memory formation. Then, I’ll provide neuropsychological evidence that hippocampal damage impairs performance on attention tasks that tax relational representations, particularly spatial relational representations. I will then provide pharmacological evidence that hippocampal contributions to attention and perception may be mediated by cholinergic modulation — a switch that can toggle the hippocampus between internally and externally oriented states. Finally, I’ll demonstrate that hippocampal memories enable preparation for upcoming attentional states and may help resolve competition between similar memories to guide attention. Together, this line of work highlights the tight links between attention and memory — links that are established, at least in part, by the hippocampus.