motor cortex.However,this assumption is not valid because Broca’s area
is known to be activated during nonspeech tongue movements (Petersen
et al.1988).A half-century ago (Nielsen 1948),singing was said to be
bilaterally represented in the front part of area 45 (part of Broca’s area
on the left).Although the means are now available for better pinpoint-
ing the neurological foci that control singing,the crucial experiment
remains to be done:subjects could be imaged using combined PET and
MRI technology (the latter identifies exact anatomical regions that are
activated) as they sing two different kinds of songs.The first would be a
familiar song with words.Under the second condition,each subject
would be asked to sing (by humming or by repeating one syllable) a
familiar piece of music that,to avoid unconscious priming,is not associ-
ated with words (e.g.,Beethoven’s Fifth Symphony).Until such research
is conducted,the precise foci associated with different kinds of singing
in the brain will remain a mystery.The Brains of Musicians
A number of gross anatomical differences were discovered that distin-
guish the brains of musicians from those of nonmusicians.One of the
most interesting pertains to the planum temporale (PT),which is larger
in the left than in the right hemisphere in most right-handed people,and
has long been thought to be important for comprehending language.As
it turns out,the PT of musicians with absolute pitch is significantly larger
on the left relative to the right side than is the case for other musicians
or nonmusicians (Schlaug et al.1995b).Since musicians with absolute
pitch do not differ from their matched controls in visual-spatial or verbal
tests (Picone et al.1997),it appears that they are more dependent on the
left PT for processing musical stimuli than people who lack absolute
pitch.This is in keeping with the well-known suggestion that musicians
rely more on the left hemisphere to process certain aspects of music,
such as melody,that are largely the domain of the right hemisphere in
nonmusicians.
The anterior half of the midline area of the corpus callosum (the large
fiber tract that connects the two hemispheres in figure 13.2) is signifi-
cantly larger in musicians who began musical training before the age of
7 than in nonmusicians (Schlaug et al.1995a).These authors interpreted
their finding as indicative of increased communication between the right
and left frontal lobes (e.g.,premotor and supplementary motor hand rep-
resentations).In another study (Amunts et al.1996),the presumed motor
hand cortex (as reflected in the depth of the central sulcus) was relatively
enlarged in right-handed professional keyboard players compared with
nonmusicians.As one would expect for right-handers,both musicians and
nonmusicians have a significantly deeper left than right central sulcus.206 Dean Falk