Tracing Memories in the Brain

A neuropsychologist and assistant professor, Dr. Monika Schönauer, has obtained a grant of more than 1.3 million euros from the German Research Foundation (DFG) for an Emmy Noether junior research group. Under her leadership, the team will investigate during the next six years how and where new memories are stored in the brain. “Experiences leave traces in the brain known as memory engrams. Using novel imaging methods, it is now possible to locate such engrams in humans and to follow their development,” explains Schönauer. The results of her work, she says, are of significance for basic research and may be applied in clinical and teaching contexts. Schönauer moved from Princeton University in the US to the University of Freiburg, where she is an assistant professor at the Institute of Psychology.

It is still unclear what determines if an event leaves a neural trace and for how long the trace will persist. In order to gain new insights, researchers need to observe the formation and development of memory traces in the brain. To ensure that newly formed memories or learned content remain intact, they must be consolidated and permanently stored in long-term memory. During the course of this stabilization, memories become independent of the hippocampus, which is located in the interior of the brain, and instead come to rely on the outlying parts of the cerebral cortex, the neocortex. “This process is called systemic memory consolidation,” says Schönauer. “We assume that repeated activation of neural networks in the neocortex plays a decisive role, for example through repeated rehearsal while awake or through reactivation during sleep,” she continues. Until now, the standard position has been that the neocortex only learns slowly,” adds Schönauer. Yet newer studies have shown that memory traces can also be formed early on in the neocortex, rather than only in the hippocampus.

Three conditions can foster rapid storage of memories or learned content: memory recall, learning spaced across longer repetition intervals, and sleep. The goal of the neuroscientist’s research is to investigate these three conditions more closely. Working together with her team, Schönauer aims to determine, among other things, when memory traces form in the neocortex and how these are different from those in the hippocampus. Beyond that, Schönauer would like to examine whether these physical memory traces can inform us about what someone has learned beforehand. The results of this project could contribute to re-formulating standard models of memory consolidation and how we form long-term memories.

The financial support of the Emmy Noether group enables junior researchers to form independent groups in their field of interest.