the observed right fusiform activation may implicate that area in the visual processing of
musical notes. Such a function would be analogous to visual word processing by left
fusiform.50–53These implied parallel locations for comparable reading functions in music
and language are consistent with other functional and structural correspondences.16–20
Each of the three conditions activated different subareas of two major areas in frontal
cortex, a lateral region, BA 6, and an inferior lateral region, BA 44/45 (Figure 17.5). These
activations were bilateral, although stronger on the left side. In both of these major areas,
the rhythm task activated superior subareas, the melody task activated inferior subareas,
and the harmony task activated subareas between those two activations. These two major
areas are currently associated with sequencing motor behaviour and with recognizing
actions.54–59However, there was no activation detected in supplementary motor area
(SMA) medial BA 6, as has been found in neuroimaging studies of song imagery.^7 In addi-
tion, there was no activation in primary motor areas. Therefore, the activation of these
areas in the present conditions does not seem related to motor preparation as such,
whether for subvocal singing or for imagined playing of an instrument. It is possible that
these activations are involved in translating the notes to abstract motor-auditory codes.
Such a translation process may be a natural component of expert score reading.
The melody, harmony, and rhythm tasks each also produced distinct patterns of activity
in auditory cortex (Figure 17.6). During the melody condition, there were strong activa-
tions in secondary auditory association areas, specifically in bilateral superior (BA 22) and
bilateral, strongly right, middle temporal (BA 21) cortex. The harmony task produced
bilateral activation, more on the left side than the right, in middle (BA 21 and 20), pos-
terior (BA 37), and superior (BA 22) temporal cortex. The rhythm condition produced only
minor activation in left inferior (BA 20) and bilateral middle (BA 21) temporal cortex.
Superior temporal activation for melodic and harmony tasks, but not rhythmic processing,
is consistent with neuropsychological data showing that superior temporal lesions spare
rhythmic processing but cause impaired melodic perception.6,11,60The activation of such
secondary auditory regions bilaterally during these comprehension tasks is also in accord
253Figure 17.5 Activations in different subareas of a major cytoarchitectonic area of frontal cortex (BA 44) as musi-
cians sight-read a J. S. Bach chorale score and listen for performance errors in harmony, melody, or rhythm.^46
These are group mean PET images for each task (contrasted with passive listening control) overlaid on MRIs. PET
data are z-scores displayed on a colour scale ranging from 2.54 (yellow;p0.01) to 4.0 (red;p0.0001). (See
Plate 9 in colour section.)