Extensive learning is associated with gray matter changes in the right hippocampus

Longitudinal voxel-based morphometry studies have demonstrated increases in gray matter volume in hippocampal areas following extensive cognitive learning. Moreover, there is increasing evidence for the relevance of the subiculum in the context of learning and memory. Using longitudinal FreeSurfer analyses and hippocampus subfield segmentation the present study investigated the effects of 14weeks of intensive learning on hippocampal and subicular gray matter volume in a sample of medical students compared to control subjects not engaged in any cognitive learning activities. We found that extensive learning resulted in a significant increase of right hippocampal volume. Volume of the left hippocampus and the subiculum remained unchanged. The current findings emphasize the role of the hippocampus in semantic learning and memory processes and provide further evidence for the neuroplastic ability of the hippocampus in the context of cognitive learning. •The first study to investigate the effects of learning on hippocampal and subicular gray matter volume.•Results indicate a significant increase in gray matter volume of the right hippocampus.•Findings suggest that plastic changes become manifest within several weeks.•Findings illustrate that plastic changes are strongly lateralized.•Findings indicate that plastic changes do not specifically affect subicular substructures.