Brittany L. Heckel
The field of motor rehabilitation is in need of more efficient and effective motor rehabilitation strategies. A promising new approach may lie in priming the motor system through repetitive exposure to movement-associated tones. For instance pianists can improve their performance of a previously practiced musical piece just by listening to the piece before the next time they play. It is unknown, however, if exposure to a novel sequence of movement-associated tones can actually improve motor performance.
The aim of our study is to determine the effect of exposure to a novel, movement-associated tone sequence on the subsequent learning of a sequential motor task. We hypothesized that motor learning of a sequential key-press task would be facilitated by previous exposure to a tone sequence that is congruent with the movement task (meaning that the tones in the sequence are associated with movements as follows: highest pitch corresponds to the most rightward key press, the lowest pitch corresponds to the most leftward key press, etc.).
Participants began the experiment by completing a 30 minute association phase, where they were instructed to press four experimental keys as they listened to the specific tone each key press elicited. This was done with the intention of inducing an association between an individual tone and a certain key press. For the subsequent baseline determination of motor performance (response times) subjects had to respond to visual stimuli presented randomly on a monitor by pressing the corresponding key as quickly and as accurately as possible. Each subject was then required to memorize a 12-unit tone sequence played over 20 minutes. Response times for motor sequences congruent (group 1, n=5) and incongruent (group 2, n=5) to the learned sequence were measured at 1 minute, 6 hours, 24 hours, and 30 days later.
After analyzing participant response times, we found a significant group x session interaction (mixed-factorial ANOVA, p <0.05), indicating that subjects who listened to the congruent tone sequence improved their motor performance across sessions, while those who listened to the incongruent sequence either became worse at the task (their response times became slower) or improved to a lesser degree than the congruent group.
Our findings support our hypothesis that repetitive exposure to a novel sequence of tones can prime the motor system for the execution of a new, never physically practiced motor sequence. This effect could be used to assist in motor rehabilitation. Going forward, we would like to continue to explore this phenomenon by testing more participants and analyzing the electroencephalography (EEG) data we collected to determine the functional connectivity of the auditory and motor areas of the brain activated during this experiment.
Last updated December 23, 2013