Here is another bit on music or musicians. (I seem to be doing a fair number of postings in this area, maybe because I'm back into more hard core piano playing since returning to Fort Lauderdale...my hands are fatigued after 3 hours of Dvorak and Dohnanyi piano quintets yesterday.) Rosenkranz et al. show that an overly expanded spatial integration of proprioceptive input into the hand motor cortex that can cause deficiencies in hand motor controls (dystonia) can be reversed by proprioceptive training in pianists with musician's dystonia to the pattern seen in healthy pianists. (The training intervention requires the subject's attention to be focused for 15 min on random vibrations delivered to three hand muscles.):
Professional musicians are an excellent model of long-term motor learning effects on structure and function of the sensorimotor system. However, intensive motor skill training has been associated with task-specific deficiency in hand motor control, which has a higher prevalence among musicians (musician's dystonia) than in the general population. Using a transcranial magnetic stimulation paradigm, we previously found an expanded spatial integration of proprioceptive input into the hand motor cortex [sensorimotor organization (SMO)] in healthy musicians. In musician's dystonia, however, this expansion was even larger. Whereas motor skills of musicians are likely to be supported by a spatially expanded SMO, we hypothesized that in musician's dystonia this might have developed too far and now disrupts rather than assists task-specific motor control. If so, motor control should be regained by reversing the excessive reorganization in musician's dystonia. Here, we test this hypothesis and show that a 15 min intervention with proprioceptive input (proprioceptive training) restored SMO in pianists with musician's dystonia to the pattern seen in healthy pianists. Crucially, task-specific motor control improved significantly and objectively as measured with a MIDI (musical instrument digital interface) piano, and the amount of behavioral improvement was significantly correlated to the degree of sensorimotor reorganization. In healthy pianists and nonmusicians, the SMO and motor performance remained essentially unchanged. These findings suggest that the differentiation of SMO in the hand motor cortex and the degree of motor control of intensively practiced tasks are significantly linked and finely balanced. Proprioceptive training restored this balance in musician's dystonia to the behaviorally beneficial level of healthy musicians.