positions relative to one another (Sergent 1993).Listening to a score,as
opposed to hearing scales,adds area 22 on the right side,affirming that
listening to music involves differential activation of the right hemisphere,
as is widely believed.Of interest,reading a score while listening to it adds
another area to those that are stimulated by each activity alone,namely,
the top part of the supramarginal gyrus (area 40) in both hemispheres
(star and cross-hatching) that,on the left,is profoundly important for
grasping the symbolism of language.Thus,Sergent et al.believe that the
superior part of the supramarginal gyrus on both sides is important for
mapping printed musical notation to its auditory representations,and
they note that this area is adjacent to the inferior part of area 40 that,in
the left hemisphere,is involved (along with area 39) in the same kind of
mapping for words.
Finally,the main task investigated by Sergent et al.shows that sight-
reading,playing,and listening to an unfamiliar piece is neurologically
more demanding than one might expect from the sum of the neurolog-
ical substrates of each activity.In addition to the areas outlined above,
two areas are recruited that are not activated by any of these activities
alone.One of these,the superior parietal lobule,or area 7 (star),is acti-
vated in both hemispheres.This area is important for realistic awareness
of one’s own body scheme,and also functions as sensory association
cortex that unifies and interprets incoming sensory stimuli from the
opposite side of the body into whole concepts.For example,a blindfolded
pianist with a lesion in part of area 7 on the left would not be able to
identify a piano key as such by touching it with his right hand,although
he would know that it was cool,relatively small,and moved when
pressed,but these sensations would not be synthesized into the concept
of a piano key.Sergent et al.suggest that area 7 also mediates the trans-
formation from sensory visual input (score reading) to motor output
(skilled finger movements).
In addition to the left motor and premotor and right cerebellar acti-
vation that one expects from the simple playing experiment described
above,another frontal lobe area is recruited in the left hemisphere in the
reading-playing-listening task.This is the superior portion of area 44,the
top part of Broca’s speech area (star and cross-hatching) that is below
the frontal lobe writing area (Xs).This finding makes perfect sense from
a neurological perspective when one considers the organization of the
primary motor cortex.Thus the lower portion of Broca’s area borders
and stimulates primary cortex for the laryngeal and oral organs of
speech,the superior part of area 44 in the left hemisphere is closer to
the right hand motor area,and the writing area above that borders hand
representation and is relatively close to primary cortex for the arm and
shoulder.In other words,the part of 44 that is recruited during the com-202 Dean Falk