371prospective databank of anatomical MR images of musicians and nonmusicians, we
selected MRIs of 56 classically trained, professional musicians matched by gender, age, and
handedness to a control group of nonmusicians. In order to compensate for the high inter-
subject variability in cerebellar volume, absolute cerebellar volume was normalized as a
percentage of total brain volume. We found a significant gender effect with female subjects
having a higher relative cerebellar volume although males showed a trend for a higher
mean absolute cerebellar volume and total brain volume. Male musicians had a signific-
antly higher mean relative cerebellar volume (10.4 vs 9.9 per cent; Figure 24.4; Table 24.2)
compared to male nonmusicians. This was not due to a difference in total brain volume
since male musicians and male nonmusicians did not show any significant difference in
total brain volume. No significant difference in relative cerebellar size was found when
female musicians were compared with their nonmusician counterparts. However, female
musicians had a trend towards a higher absolute brain volume (Table 24.2).
Table 24.2 Absolute brain volume and absolute and relative cerebellar volume in musicians and nonmusi-
cians. There was a significant difference in relative cerebellar volume comparing male musicians to male
nonmusicians (p0.05), but no difference in relative cerebellar volume comparing female musicians to female
nonmusicians. Female musicians showed a trend for total brain volume differences (p0.08)
Group Brain volume (cc) Rel. cerebellar volume (%) Abs. cerebellar volume (cc)
Musicians (males;n30) 1412.0 (84.5) 10.4 (0.7) 146.2 (9.3)
Nonmusicians (males;n30) 1405.2 (120.0) 9.9 (0.7) 139.9 (14.4)
Musicians (females;n26) 1308.4 (92.3) 10.5 (0.6) 136.7 (9.6)
Nonmusicians (females;n26) 1266.6 (76.7) 10.6 (0.7) 134.8 (11.4)
Figure 24.4Dorsal and ventral views of the cerebellum. Cerebellar volume was normalized to whole brain
volume to reduce intersubject variability. The relative cerebellar volume of male musicians was about 5 per cent
larger than that of matched nonmusicians. There was a discrete positive correlation between cerebellar volume
and intensity of musical training.
Dorsal view Ventral viewM Nmus (MB166)M Mus (MB172)