Hippocampal mechanisms underlying the resolution of competition in memory and perception.

Behaving adaptively requires selection of relevant memories and sensations and suppression of competing ones. We hypothesize that these mechanisms are linked, such that hippocampal computations that resolve competition in memory also shape the precision of sensory representations to guide selective attention. We leverage fMRI-based pattern similarity, receptive field modeling, and eye tracking to test this hypothesis in humans performing a memory-dependent visual search task. In the hippocampus, more distinct representations of competing memories are associated with the accuracy of memory-guided eye movements. In visual cortex, preparatory coding of remembered target locations precedes search successes, whereas preparatory coding of competing locations precedes search failures due to interference. These effects are linked: more distinct hippocampal memories are associated with lower competitor activation in visual cortex, yielding more precise preparatory representations. These results demonstrate a role for memory distinctiveness in shaping the precision of sensory representations, highlighting links between mechanisms that overcome competition in memory and perception.