Gottfried Schlaug - US grants

Research has demonstrated structural differences in the brains of musicians compared to non-musicians. However, it is not yet known whether these differences are inborn or develop through long-term stimulation during critical periods of brain development. On the one hand, the brain may be capable of changes not only in functional brain networks, but also in structural components as a response to increased use. On the other hand, the brains of musicians may be atypical prior to training, both anatomically and functionally. If so, becoming a professional musician may be partly genetically predetermined. Research has also demonstrated that music training in children results in long-term enhanced visual-spatial and mathematical performance. The underlying neural basis of such enhancements is unknown. Possible explanations include changes in arousal, mood, and priming of particular brain regions. However, long-term changes in brain function or structure, such as strengthening of existing brain connections or the formation of new connections or even new cells and a more elaborate system of connections, might be induced by learning and practicing on a musical instrument. This pilot longitudinal study will follow young children at the beginning of their music training over a period of three years and compare them to a control group of children matched in gender, SES, handedness, age, and overall IQ.

Using high-resolution MR images within subjects over time, the research will begin to answer questions such as the following: Does the amount of instrumental practice correlate with structural brain differences and/or do levels of musical talent/skill predict structural brain differences either prior to or as a consequence of training? Is visual-spatial and mathematical reasoning enhanced by music training? If so, are these non-musical cognitive outcomes related to amount of time spent practicing, degree of improvement in reading music notation, and/or level of musical talent/skill? Do gains in visual-spatial and mathematical reasoning, if found, correlate with structural brain enhancements over the course of musical training?

This research has potential far-reaching implications. First, children often begin music study at an age when the brain is at a critical phase of development and maturation. If structural brain changes or use-dependent brain growth occur, it would have important implications for early childhood education. Second, the results might help to explain why certain children succeed and others fail in mastering musical instruments. Third, demonstrating improvements in domains other than music as a function of music training would have strong implications for both general and music educational practice. Fourth, this research will provide testable hypotheses about the neural basis of transfer effects. Transfer is a key issue in educational theory, and has not only applied value but also theoretical value, since a demonstration of transfer helps us to understand how mental capacities are organized and related to one another.

Research has revealed structural and functional differences in the brains of adult instrumental musicians compared to those of non-musician controls. It is not yet known whether these differences are inborn, develop as a result of long-term stimulation/training during critical periods of brain development, or can be attributed to a combination of the two. Research has also demonstrated that music training in children results in long-term enhancement of visual-spatial, verbal, and mathematical performance. However, the underlying neural basis of such enhancements, and whether or not learning and practicing a musical instrument can induce these enhancements, is yet unknown. In the fall of 2002, a pilot longitudinal study funded by the National Science Foundation began to compare children who were about to start instrumental music training with those who were not. At baseline, the groups showed no significant differences in morphometric and functional brain parameters or in results of motor, auditory, and cognitive tests. However, after 15 months of observation, significant differences had emerged in some primary domains (motor and auditory skills) as well as in melodic and rhythmic processing during functional brain imaging studies, but no cognitive transfer effects have yet been seen. With support from the National Science Foundation, Drs. Schlaug and Winner will continue to follow the original sample of young children for three additional years in order to test the following hypotheses: (1) Children in the instrumental group should show greater improvement on all cognitive outcomes, more brain growth in areas previously found to be enlarged in adult musicians, and a left-hemispheric shift in the functional brain correlates of music processing; (2) Training intensity should predict level of change on all outcome parameters; (3) String training may show different effects on the sensorimotor system than those shown by keyboard training; (4) Skill at reading notation should predict performance on visual-spatial tasks and subtests of math that require spatial reasoning, proportion, and ratio; (5) Skill in music processing should predict performance on phonemic awareness.

This project will demonstrate the relationship of skill acquisition, learning, and the effect of transfer to structural and functional brain changes during critical periods of brain maturation, all of which have important implications for early childhood education. Transfer is a key issue in educational theory that has both applied and theoretical value since it helps us to understand how mental capacities are organized and related to one another. This research will provide testable hypotheses with regard to the neural basis of transfer. While music education should never be justified solely in terms of its impact on extra-musical learning, the discovery of cognitive transfer from music learning and the neural basis of such transfer would be an important, beneficial "side-effect" of music training.

DESCRIPTION (provided by applicant): Although we all know one or more individuals who can't sing in tune, the neural correlates of this disorder and what it might reveal about models of communication control remain elusive. In addition to an inability to sing in tune, one characteristic marker of tone-deafness is an abnormally large psychophysical pitch discrimination threshold of more than one semitone. The inability to discriminate fine pitch differences may be an epiphenomenon of the disorder, or it could be related to the presumed auditory-motor dysfunction that underlies disabled production of vocal pitch. Pilot and previous data from morphometric, functional imaging, and Event- Related Potential (ERP) studies point towards functional and structural abnormalities in regions involved in auditory feedback control and sound-motor mapping, rather than dysfunctions in primary auditory cortex. In considering that the inability to sing might be reflective of problems in auditory-motor integration including feedforward and feedback control mechanisms, the present theoretical framework allows us to generalize existing models of speech perception and production to the domain of singing as an instance of intoned-speech. Our general hypothesis is that tone-deafness is a result of dysfunction in a network of brain regions involved in auditory feedback and feedforward control of vocal pitch production. We plan to test this hypothesis by first identifying the behavioral and neural substrates of tone-deafness. By combining neuroimaging and psychophysical experiments of pitch production, including the use of pitch- shifted auditory feedback, we will test the neural mechanisms responsible for auditory feedback control and sound-motor mapping as well as the interaction of these two systems (Aim 1). We will then reverse-engineer the perceptuomotor pathway by creating temporary regional dysfunctions using a new method of non-invasive brain stimulation (transcranial direct current stimulation - TDCS) (Aim 2). Based on pilot pitch production results, brain stimulation can temporarily induce tone-deafness in normal individuals, thus allowing us to assess our regional hypotheses using psychophysical measures that have been evaluated in experiments from the first aim. Examining the neural correlates of tone-deafness and creating a tone-deaf equivalent in normal subjects will offer new insights into the interactions of auditory and motor systems in the brain in normal and disordered speech as well as in non-speech communication.