Researchers at the University of Birmingham have uncovered a surprising role of the hippocampus – linking this part of the brain to the control of skilled actions such as handwriting, typing, and playing music.
The hippocampus is traditionally associated with memory for events and spatial navigation, but a new study challenges these long-held distinctions and opens new possibilities for rehabilitation of neurological and neurodegenerative disorders that affect movement.
Publishing their findings today (26 Sep) in The Journal of Neuroscience, the research team reveal evidence suggesting that the hippocampus plays a role in retrieving and organising flexible movement sequences from memory.
The research team reanalysed functional MRI (fMRI) data to focus on brain activity in key subcortical regions as participants performed well-practiced finger sequences from memory on a force-sensitive keyboard, resembling piano playing.
While motor areas in the basal ganglia and the cerebellum – typically associated with the development of "muscle memory" for learned motor skills – showed increased activity during the sequence task, the study uncovered that it was the hippocampus, rather than these motor areas, that held information about the finger order of the sequence a participant was about to perform. This is like predicting whether a person would type "fears" or "fares" from the activity in the hippocampus alone.
Associate Professor and senior author of the study, Dr Katja Kornysheva, from the University of Birmingham, commented: "This result is interesting because it shows that the brain systems for episodic and procedural memory work together more than we thought. This is especially true when we need to remain flexible and switch between learned sequences, for example when typing on a computer keyboard or playing music with others."
Dr Rhys Yewbrey, a former doctoral student in Kornysheva's research group and first author of the study added "Our research suggests that the hippocampus may be important in skilled and flexible motor control, for setting up a course plan of action. This knowledge could help develop more effective training programs for neurological rehabilitation of actions, as well as for speeding up the acquisition of new skills."
The researchers hope their findings will encourage further exploration into the interaction between memory systems and inspire novel therapies that can enhance both motor function and cognitive health.
