Not just movement control: A study clarifies the complex functions of the long-underestimated cerebellum. It therefore plays an important role in what is known to be the particularly intensive imprinting of emotional impressions in the memory: when the relevant information is stored, it communicates intensively with various areas of the cerebrum, brain scans show. The findings add to our knowledge of how the cerebellum functions and could be important for understanding psychiatric problems such as post-traumatic stress disorder, the researchers say.
For a long time it was overshadowed by the cerebrum: the cerebellum was hardly assigned any more complex functions - it was considered the rather simple center of movement control. However, brain research has already clearly refuted this: Studies show that the strongly furrowed structure in the area of the rear base of the skull, which is very rich in nerve cells, is not only important for motor function but also involved in higher brain functions. Among other things, an activation of the cerebellum in fear reactions has already been shown.
As part of their study, scientists led by Matthias Fastenrath from the University of Basel have now investigated the extent to which the cerebellum could also be involved in an effect that everyone probably knows from personal experience: Both positive and negative emotional experiences and impressions are particularly important strongly in memory. This has to do with the fact that they can often have an important meaning in our lives. Intensive remembering can, for example, help to avoid dangerous situations in the future. In excess, however, the effect can also lead to severe mental stress.
Focus on emotion and memory
In a large-scale study, de Quervain and his colleagues investigated what happens when emotionally linked impressions are stored in the brain. More than 1,400 study participants were presented with images that were emotionally appealing and neutral for comparison, while the researchers recorded their brain activity using functional magnetic resonance imaging. The positively emotional images were, for example, people in victory poses or cute animal photos - the negative ones were violent scenes. Household items, among other things, were shown as neutral impressions.
As was to be expected, in a later memory test, the study participants remembered the emotionally positive and negative images much better than the neutral ones. In this way, the researchers were able to examine specifically how this more intensive memory storage was reflected in the brain. Basically, a familiar pattern emerged: the amygdala was activated – a brain structure that is important for processing emotions. The improved storage of emotional images was also associated with increased brain activity in familiar areas of the cerebral cortex. However, the scientists have now also been able to demonstrate strong activation in the cerebellum.
Role in the emotional storage network
As they report, it became apparent that the cerebellum exchanges information with various areas of the cerebrum during the particularly intensive storage of emotional impressions. Accordingly, it receives data from the so-called gyrus cinguli, a brain region that plays a role in the perception and evaluation of feelings. As reflected in the results of the brain scans, the cerebellum in turn sends signals to different brain regions. These include the amygdala and the hippocampus, whose central role in memory storage is known.
"The findings indicate that the cerebellum is an integral part of a network that is responsible for the improved storage of emotional information," says senior author Dominique de Quervain from the University of Basel, summarizing the results of the study. She is now expanding our knowledge of the role of the cerebellum in complex cognitive and emotional processes. According to the researchers, however, it is also a result of basic research that could be incorporated into clinical projects: "The results could be important for understanding psychiatric problems such as post-traumatic stress disorder or autism spectrum disorders," the scientists write .
Source: University of Basel, specialist article: PNAS, doi: 10.1073/pnas.2204900119