0.7 Music, biological evolution, and the brain  (Page 17/30)

Preliminary data reported in Schlaug et al. (2008) support this idea by showing that a patient who underwent forty sessions of MIT showed greater verbal fluency and greater right hemisphere activation when speaking than did a patient who underwent SRT. Furthermore, Schlaug et al. (2009) have reported structural changes in the brains of several patients who underwent MIT. Specifically, these patients show an increase in the thickness of a large fiber tract (the right arcuate fasciculus) connecting the frontal and superior temporal lobes. Furthermore, there was a trend for a correlation between the degree of thickening and the degree of improvement in verbal fluency, though the trend did not reach statistical significance, possibly due to the small sample size (more patients are currently being studied). Structural measures of the right arcuate fasciculus were conducted before and after seventy-five sessions of MIT therapy using MRI diffusion tensor imaging (DTI) in living patients.

Since this research program is still in its early stages, the findings raise numerous questions, including the reliability of the above correlation when more patients are added and the degree to which changes in the right arcuate fasciculus are specifically driven by MIT (versus SRT or no therapy). Furthermore, the physiological basis of the observed fiber-tract thickening is not yet clear. For example, such thickening could be due to use-related increases in the number of axon collaterals in the fasciculus or use-related increases in the diameter of existing axons. I thank Robert Turner for bringing this point to my attention. Nevertheless, the research of Schlaug and colleagues suggests that musical behaviors can have lasting effects on nonmusical brain functions after stroke. Furthermore, this research provides a model for studies seeking to examine the effects of music on other brain functions, as discussed in the next section.

4.3 the biological power of music: future directions

The two examples above suggest that music can have lasting effects on nonmusical abilities. The second example provides only preliminary data, but was included because it illustrates the kind of approach needed for studying the biological effects of music on brain function. Specifically, there is a need for experimental studies that combine longitudinal behavioral and neural measurements to examine how music influences nonmusical abilities in a lasting fashion (cf. Altenmüller et al., 2009). While studies that collect brain data are particularly valuable, purely behavioral studies are also useful if they lead to hypotheses for underlying neural mechanisms, as in the Särkämö study above. Well-controlled studies from the field of music therapy are of considerable interest in this regard (e.g., Bradt et al., in press).

While the examples above focused on adults, an important direction for future work concerns children, because their developing brains are even more malleable than those of adults (Huttenlocher, 2002). Indeed, music may be a particularly efficacious technology for shaping brain function in children because they are drawn to music from a very young age, meaning that it is relatively easy to get them to engage in musical behaviors repeatedly.