As the brain is
the substrate of all mental processes and their behavioral outcome, and
as musicianship is certainly a complex of such processes and their resultant
behavioral performances, it would seem that the brains of musicians might
be different than the brains of non-musicians. What is now known? Although
this complex issue can't be covered completely here, we can summarize
some interesting findings that do indicate how the brains of musicians
and non-musicians differ.
Before we get
started, two points should be made. First, there is no strict dividing
line between musicians and non-musicians. The former are not all professionals
or those with eight years of formal music education, or necessarily any
formal musical education. When does a beginning music student become a
musician? An initial solution to this problem is to compare groups of
people at opposite ends of a continuum of musicality, such as comparing
professionals with those who are musically naive.
Second, they might be differences in the brains of the two groups that
cannot be discerned yet because of the current state of technology. For
example, the stored knowledge of how to transpose to different keys is
not yet detectable by brain scans. Thus, failures to find certain differences
may not be sufficient reason to categorically reject such differences.
points in mind, we begin with the cerebral hemispheres. Overall, and somewhat
simplified for present purposes, the left hemisphere (LH) is most important
for analytic processes (e.g., details) while the right hemisphere (RH)
seems more important for processing global information (e.g., patterns).
Notably, most language processes depend on the LH (in right handed individuals).
It is often wrongly assumed that all music processing takes place in the
RH. Many years ago, Bever and Chiarello discovered that naive listeners
depend on the RH for discriminating melodic sequences but musicians use
the LH for this task (1). It seems that musicians may process melodies
in a more analytic, "language-like" manner than non-musicians.
Are there any
anatomical differences between the LH and RH in musicians vs. non-musicians?
In a very recent study, Schlaug et al. used magnetic resonance imaging
(MRI) to determine the sizes of the "planum temporale" in the left and
right hemispheres. This structure includes auditory association cortex.
Groups of professional musicians and non-musicians were matched for age,
sex and handiness. The authors found that musicians had a larger left
vs. right planum temporale than non-musicians. Thus, one could conclude
that the brains of musicians show gross anatomical differences from those
of non-musicians. However, this difference was due entirely to a subset
of musicians who had perfect pitch; other musicians did not differ from
the control group. Therefore, the distinction is not "music vs. non-music"
but "perfect pitch vs. "non-perfect pitch". These findings underscore
the need for thoughtful analysis and restraint against jumping to conclusions
but do reveal that perfect pitch may be due to more brain tissue being
"allocated" to the auditory cortex.
findings also have a physiological counterpart. For example, Barnea et
al recorded electrical potentials in the cerebral cortex that are elicited
by musical stimuli. They found differences in the extent of cortical areas
that respond, between musicians who do have perfect pitch compared to
those who do not.
results pertain to perfect pitch, there are neurophysiological differences
that distinguish musicians from non-musicians For example, Besson, Faita
and Requin studied differences in the processing of melodic material.
They presented musical phrases that ended either in a congruous or incongruous
note. The brain wave response evoked by this ending note differed between
the groups, including a faster brain response by the musicians.
in the way that the brain processes timbre also have been detected. Crummer
and co-workers required musicians with and without perfect pitch and non-musicians
to perform timbre discrimination tasks. For example, the same pitch was
compared for cello vs. viola (easy), wood vs. metal flute (moderate difficulty)
and instruments of slightly different size (B-flat vs F tubas), which
was most difficult. The amplitude of brain potentials evoked by the notes
was greater in musicians vs. non-musicians for the difficult discrimination
and the brain potentials occurred fastest for musicians with perfect pitch.
studies point to the following conclusions. First, perfect pitch, but
not musicality per se, apparently has a cortical anatomical basis. Second,
the processing of selected musical elements, as revealed by brain potentials,
is facilitated in musicians compared to naive listeners. Third, musicians
can process music in a different cognitive mode than naive listeners.
The latter two findings suggest that a transition from RH to LH processing
of music might be a fundamental aspect of the transition from musically
naive to musically adept.
It would be
interesting to assess the presumptive development of LH capabilities for
relevant elements of music by both behavioral tests and by the recording
of brain responses at various stages of musical training. The technology
is readily available, present in thousands of medical and college settings,
non-invasive and in widespread use for diagnostic and study purposes.
Why not apply it to education? This would seem to be a potentially powerful
way to join the separate expertise of music educators and relevant neuroscientists
in an enterprise that would clearly yield results greater than the sum
of its parts.