Poster C101, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Resting-state medial temporal lobe connectivity with reward centers predicts how motivation impacts learning
Lea E. Frank1, Alison R. Preston2, Dagmar Zeithamova1; 1University of Oregon, 2University of Texas at Austin
Memory is influenced by motivation, such as a promise of future monetary reward for remembering an event. Reward-based memory modulation has been shown to rely on interactions between brain structures sensitive to reward, such as the midbrain, and those supporting episodic memory, such as the medial temporal lobe (MTL), during motivated encoding. Here, we tested whether intrinsic connectivity between the memory-related (MTL) and reward-related (midbrain, striatum, orbitofrontal cortex) regions during rest can predict reward modulation and if these connections increase as a function of motivated encoding. Subjects underwent resting-state functional MRI before and after a monetary incentive encoding task in which a potential monetary reward cue (penny, dime, or dollar) was followed by a pair of objects to be remembered. The associated monetary value was awarded to the subject for each correctly recalled object pair. Participants remembered high-value pairs better than medium- and low-value pairs. However, reward modulation of memory varied across individuals. Resting-state fMRI revealed that MTL-midbrain connectivity significantly increased from pre- to post-learning, suggesting that interactions between reward and memory systems can be upregulated in response to a motivated encoding task. Intrinsic connectivity further tracked individual differences in reward modulation, such that subjects who demonstrated greater sensitivity to reward also showed significantly greater intrinsic MTL-striatum and MTL-orbitofrontal connectivity during both pre-encoding and post-encoding rest scans. These results suggest that intrinsic connectivity between reward- and memory-related regions underlies individual differences in reward modulation and highlight the dynamic interactions between these systems that extend beyond the period of learning.
Topic Area: LONG-TERM MEMORY: Episodic