Poster E83, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
The hippocampus promotes effective saccadic information gathering in humans
Heather D. Lucas1, Melissa C. Duff2, Neal J. Cohen1; 1University of Illinois Urbana-Champaign, 2Vanderbilt University
It is well established that the hippocampus is critical for human learning and memory. Recent evidence suggests that one way in which the hippocampus contributes to learning is by allowing individuals to explore information in efficient, adaptive ways under active study conditions. Here we demonstrate that the link between the hippocampus and exploration extends even to eye movements made during an otherwise passive encoding task. In two experiments, we use the information-theoretic measure of entropy to assess the amount of randomness or disorder in participants’ item-to-item gaze transition patterns as they studied multi-item visuospatial displays. In Experiment 1, scanpath entropy at study was negatively associated with performance on a relational memory task in both within- and across-subject analyses. In particular, participants who engaged in higher-entropy viewing showed a greater tendency to later “swap” or reverse the relative positions of objects within the array. In Experiment 2, we found elevated scanpath entropy in patients with amnesia due to hippocampal damage, suggesting that the hippocampus is necessary to adaptively constrain saccadic information sampling. These data reveal that hippocampal contributions to exploratory behaviors in humans are pervasive, operating even at the level of eye movements.
Topic Area: LONG-TERM MEMORY: Episodic