How your brain remembers motor sequences

Posted on September 11, 2019

Results uncovered the detailed map of cortical sequence representation in the human brain – results show that for locating new candidate brain areas as signal sources for motor BCI application or developing more sophisticated algorithm to reconstruct complex motor behaviour.

The best way to remember or produce long and complex motor sequences is to divide them into several smaller pieces recursively. For example, a musical piece may be remembered as a sequence of a smaller chunks, with each chunk representing a group of often co-occurring notes. These types of hierarchical organisation have long been thought to underlie our control of motor sequences from the highly skilful actions, like playing music, to daily behaviour – like making a cup of tea.

This study will provide the first direct evidence of how hierarchically organised sequences are represented through the population activity across the human cerebral cortex. Researchers measured fMRI activity patterns, while human participants produced 8 different sequences of 11 finger presses is a tough task, hence one will most likely organise them hierarchically.

Participants encoded the sequences in terms of a 3-level hierarchy; (1) individual finger presses, (2) chunks consisting of 2 or 3 finger presses, and (3) entire sequences consisting of 4 chunks. As expected, the patterns in primary motor cortex – the area that controls finger movements seemed to only depend on each individual finger movement – independent of its positioning in the sequence. Activity in higher order motor areas like the premotor and parietal cortices could be shown to encode the sequential context at the level of chunks or entire sequence. Thus, in contrast to primary motor cortex, these areas “know” what was played before and what comes after the ongoing finger press.

For the first time, the study allowed insights into the organisation of these higher-order representations. It also suggests possible loci from which we can record brain signal to control neural prosthetics to make fluent movement sequences in potential BCI applications, hoping that it will contribute in developing a new decoding algorithm.

Category(s):Adult psychological development

Source material from Science Daily

Mental Health News