AI Summary
This article explores how the human hippocampus represents information regarding the order of sequential motor actions in learned motor sequences. Using functional magnetic resonance imaging, the study found that the hippocampus specifically represents information about movements in their learned temporal position in the sequence, emphasizing its role in motor learning. Other regions of the motor network also coded for movements in their learned temporal position, highlighting the contributions of various brain regions to motor sequence learning. These findings provide insights into the relationship between different brain regions and their roles in motor skill acquisition.
Our repertoire of motor skills is filled with sequential movements that need to be performed in a specific order. Here, we used functional magnetic resonance imaging to investigate whether the human hippocampus, a region known to support temporal order in non-motor memory, represents information about the order of sequential motor actions in human participants (both sexes). We also examined such representations in other regions of the motor network (i.e., the premotor cortex, supplementary motor area, anterior superior parietal lobule, and striatum) already known for their critical role in motor sequence learning. Results showed that the hippocampus represents information about movements in their learned temporal position in the sequence, but not about movements or temporal positions in random movement patterns. Other regions of the motor network coded for movements in their learned temporal position, as well as movements and positions in random movement patterns. Importantly, movement coding contributed to sequence learning patterns in primary, supplementary, and premotor cortices but not in striatal and parietal regions. Our findings deepen our understanding of how striatal and cortical regions contribute to motor sequence learning and point to the capacity of the hippocampus to represent movements in their temporal context, an ability possibly explaining its contribution to motor learning.