How does rate influence brain activity during drumming in persons with Down Syndrome?

Persons with Down Syndrome (DS) have been repeatedly shown to have timing deficits, to move slowly, and to not follow metronomes. This timing deficit in persons with DS requires further study because timing is fundamental to movement control. Furthermore, brain imaging studies have proposed a rate effect in which increased cortical activation in the primary motor cortex was observed during increased finger movement frequency. The aim of the current study was to determine if the rate effect was present in persons with DS by comparing brain activation in self-selected and as fast as possible rates. Eight participants with DS performed unimanual drumming at their self-selected and maximal rates. Movement rate was measured at EEG was collected in the alpha (8-12 Hz) and Beta (13-30 Hz) frequencies from C3 and C4. The results showed that overall, their self-selected rates were slower than their maximal rates, indicating that they are capable of modifying their movement rate with general instructions. Furthermore, there were significant differences in Beta in which there was more activation during as fast as possible than self-selected tapping in both sides of the primary motor cortex in persons with DS. This suggests that their brains are activated in a similar manner as the typical population with respect to movement rate. Overall, our results suggest that while interventions that involve timing to specific rates are difficult, people with DS can perform at self-selected and maximal rates. The results of our study show that they can alter movement rate when provided with general instruction or additional motivation.