Poster D73, Monday, March 26, 8:00-10:00 am, Exhibit Hall C
Hippocampal contributions to reward learning
Daniela Palombo1,2, Mieke Verfaellie1,2; 1VA Boston Healthcare System Jamaica Plain, 2Boston University School of Medicine, Department of Psychiatry
Recent evidence suggests that the human hippocampus—known primarily for its involvement in episodic memory—also plays a role in a host of motivationally relevant behaviors, including value-based decision making. However, less is known about the role of the hippocampus in value-based learning. Such learning is typically associated with a striatal system, yet a small number of studies also show hippocampal engagement. It is not clear, however, whether this engagement is necessary for such learning. In the present study, we used both fMRI and neuropsychological methods to clarify hippocampal contributions to one form of value-based learning, namely reward learning. In experiment 1, healthy participants were scanned while learning reward-based contingencies (whether distinct players in a ‘game’ would win money or not) in the context of a probabilistic learning task. Here we observed recruitment of the hippocampus during learning. In experiment 2, we administered this task to amnesic patients with medial temporal lobe damage and healthy controls. Amnesic patients, including those with damage circumscribed to the hippocampus, failed to acquire reward contingencies, thus confirming that hippocampal engagement is necessary for task performance. Although future research is needed to determine the boundary conditions of hippocampal involvement in value-based learning, these findings elucidate the role of the hippocampus in learning and may clarify how the hippocampus contributes to goal-directed behaviors more broadly.
Topic Area: LONG-TERM MEMORY: Other