However,the central sulcus on both sides is deeper in the musicians,
especially those who began training at a young age,resulting in overall
less asymmetry than appears in nonmusicians.String players who began
training at an early age also differ from nonmusicians in the organiza-
tion of their brains.Specifically,the sensory cortex in the right hemi-
sphere is relatively enlarged in the region that represents the fingers of
the left hand (Elbert et al.1995).One must be cautious in interpreting
these results,however.Although musicians apparently have greater
primary cortical areas devoted to sensory and motor functions for hands,
activation in these areas is less than in those of nonmusicians during the
performance of simple repetitive finger tapping (Auer et al.1996).
Brain waves associated with certain musical tasks also differ between
musicians and nonmusicians.In one study (Besson,Faita,and Requin
1994),event-related potentials were recorded from electrodes over right
and left parietal cortices in fifteen musicians and fifteen nonmusicians as
they listened to musical phrases,some of which ended in incongruous
notes.Subjects were asked to identify the last notes as either congruous
or incongruous and,for the latter,to determine whether they were
harmonically,melodically,or rhythmically incongruous.Wrong notes
resulted in late positive components of event-related potentials that were
larger and had shorter onsets for musicians versus nonmusicians,and for
harmonic versus melodic incongruities.Both groups responded similarly
to rhythmic incongruities.It was no surprise that the authors concluded
that musicians are faster than others in detecting notes that depart from
expectation.It is curious that musicians with absolute pitch lacked or had
a greatly reduced brainwave,called a P300,in response to an auditory
oddball task that required counting atypical tones that appear infre-
quently among other auditory stimuli (Klein,Coles,and Donchin 1984).
Musicians without absolute pitch manifested a P300 during this task,
leading the authors to speculate that it may be associated with mainte-
nance or updating of working memory;whereas people with absolute
pitch may “have access to permanently resident representations of the
tones,so that they do not need,as the rest of us do,to fetch and com-
pare representations for novel stimuli” (Klein,Coles,and Donchin
1984:1308).
Shannon (1984) wondered if the spatial arrangement of instruments
in modern philharmonic orchestras,in which violins are on the left-hand
side of the stage and celli are on the right,reflects aesthetic preferences
of audiences.He therefore tested whether twenty musicians and twenty-
four nonmusicians preferred to hear music in one left-right distribution
of instruments versus another,using headphones and a lever that allowed
subjects to reverse auditory input.There were no significant effects for
nonmusicians,but musicians preferred leading (usually high-pitched)207 Hominid Brain Evolution and the Origins of Music