24
THE BRAIN OF MUSICIANS
Introduction
Musicians perform complex physical and mental operations such as translating musical
symbols into complex motor operations, performing independent movements of fingers
and hands, remembering long musical phrases, improvising music, and identifying tones
absolutely without a reference tone. The neural correlates of most of these musical opera-
tions are not fully understood yet.^1 Several studies have shown that musicians differ from
nonmusicians in certain aspects of brain function and structure,2–14but questions remain
as to whether ‘musical’ skills and functions are related to these functional and structural
differences. The commencement of motor and auditory training for students of music
starts at a time when the brain and its components are in a critical period of development.
This early commencement combined with long-term training makes musicians ideal sub-
jects in which to investigate whether the almost daily practice of auditory and motor skills
over many years leads to functional and/or structural cerebral adaptations. On the one
hand, the brain may be highly plastic, capable not only of changes in functional brain net-
works,15,16but also in structural components as a response to increased use.17–19On the
other hand, the brains of musicians may be ‘atypical’ prior to training, both anatomically
and functionally, and hence a special anatomy or brain function would be a prerequisite for
musical skill acquisition rather than its consequence.
Several animal studies have shown that microstructural changes such as increases in
number of synapses, glial cells number and volume, and capillary density occur after long-
term motor exercises and motor learning in rats within the cerebellum and primary motor
cortex.20–23More recently, studies have also shown evidence for neurogenesis, mainly in the
hippocampus, in rats reared in a complex environment^24 or as a result of long-term motor
activity (i.e. running in a running wheel) which was associated with behavioural advant-
ages.^25 It is unknown whether the sum of these microstructural changes could amount to
structural differences detectable on a macrostructural level. Only a few studies examined
the results of presumed structural plasticity in the human brain.26,27The only study in
humans besides our own studies on musicians that suggested plastic structural changes in
response to environmental demands is a study by Maguire and colleagues.^27 In this study a
larger posterior hippocampal volume was found in experienced taxi drivers who are under
intense visual-spatial demands of driving a taxi in a large metropolitan region.
Functional reorganization of adult mammalian sensory and motor cortical representa-
tions after peripheral or central stimulation or as an adjustment after injury has been found
in many different experimental animal models of brain plasticity.28–31,19Similar adaptive