Author:

Abstract:

Memory consolidation is thought to be mediated by the offline reactivation of brain regions recruited during initial learning. Evidence for hippocampal reactivation in humans comes from studies showing that hippocampal response patterns elicited during learning can persist into subsequent rest intervals. Such investigations have largely been limited to declarative memory, which is surprising given the critical role of the hippocampus in motor memory processes. The primary goal of this study was therefore to investigate whether motor learning induces persistence of hippocampal patterns into subsequent rest. Based on their critical roles in motor learning and memory consolidation processes, we also assessed persistence in the striatum and primary motor cortex (M1). Functional magnetic resonance imaging (fMRI) data were recorded during motor learning as well as pre- and post-learning resting periods from 55 young healthy adults (males and females). Patterns of brain responses were assessed with intra- and inter-regional multivoxel correlation structure (MVCS). Intra-regional multivoxel patterns during motor sequence learning within the hippocampus and the striatum – but not within M1 – were more similar to post-learning as compared to pre-learning resting epochs, indicating persistence of task-related patterns thought to reflect reactivation processes. Interestingly, the multivoxel pattern of hippocampal connectivity with the striatum (i.e., inter-regional MVCS) was strongly dissimilar between post-learning rest and task practice. Altogether, these results provide evidence for the persistence of learning-related response patterns within the hippocampus and striatum into rest following motor learning. They also suggest that striatal-hippocampal connectivity patterns elicited by task practice are reorganized in post-learning waking rest.

Significance statement