BIRMINGHAM, United Kingdom — If you’ve ever wondered how skilled musicians appear as almost one with their instrument, or how dedicated athletes can make unbelievable feats of fitness look like a walk in the park, scientists are finally offering up some answers. A team at the University of Birmingham reports that the human mind prepares for such skilled movements by “zipping and unzipping” information regarding the timing and order of movements ahead of actually performing the action.
Study authors discovered that before zipping up and moving into specific movement commands (muscle memory), the brain separates both the order and timing of movements in complex sequences as an individual begins an action. The study also found that the brain stores high-level sequencing of movement (such as order and timing) across several motor regions of the mind, in many cases across several days of training and memorizing certain action sequences, before it finally activates due to a particular trigger — like a musical cue or a starting gun.
Study authors from both the University of Birmingham and Bangor University believe their work may help improve motor rehabilitation for stroke victims.
“From handwriting to playing a musical instrument, performing sequences of movements from memory is a hallmark of skilled human behavior,” says Principal investigator Dr. Katja Kornysheva, from Birmingham’s Centre for Human Brain Health, in a university release. “What is surprising is that the brain separates these skills into their constituent features rather than encoding them as an integrated muscle memory, even after extensive training. There is a shift in information states within the brain when performing such tasks.”
“Information is retrieved from memory unzipped when we prepare it for execution, before being zipped together to start the task. Perhaps this unzipping mechanism helps us to stay flexible for adjustments, even in the final hundreds of milliseconds before we start the movement, e.g. if we need to change the speed or timing of an upcoming action.”
Order and timing are always connected in the brain
Across nearly 1,000 trials, right-handed participants (besides professional musicians) learned and memorized four keyboard sequences. They then prepared and subsequently reproduced them following a visual cue. After the training sessions, the volunteers created the keyboard sequences in an MRI scanner, measuring activity patterns across the entire brain during the task. On some trials, however, the go cue did not appear. This allowed the research team to separate preparations from the movement itself.
“We also found several brain regions which control timing during movement production, but none seemed to control order without integrating it with timing,” explains study co-author Rhys Yewbrey from Bangor University.
“There was a matching effect in our participants’ behavior – they were faster in acquiring a sequence with a new order of finger presses when they were familiar with the timing yet struggled to learn a sequence when they had to pair a previously trained order with a new timing. Perhaps timing control staying active during production allows for flexibility even after the movement has started.”
Study authors hypothesize the mind separates sequence order and timing as “what” elements representing higher-level control, which then combine to define “how” exactly someone should perform the task. These latest findings help paint a clearer picture of how skilled actions are stored and controlled in the brain, as well as why exactly they are so flexible and resilient to changes in the environment or in neurological disorders. It’s important to note that these actions don’t just apply to musical endeavors or athletics — these processes help people do everything from type on a keyboard to tie our shoelaces.
The findings appear in the Journal of Neuroscience.
