memory; right but not left lobectomy resulted in impaired recognition of timbre and tonal
memory and a lesser degree of impairment involving pitch and rhythm.^53 A different test-
ing instrument, the Musical Aptitude Profile, which involves tonal imagery (melody and
harmony), rhythm (tempo and meter), and ‘musical sensitivity’ (phrasing, balance, and
style) was used to study subjects with no musical training who had undergone either left
or right temporal lobectomy; right-sided but not left-sided surgery resulted in impairment
involving rhythm and sensitivity, not tonal imagery.^54
Patients with either left or right temporal lobectomy were presented with spoken words,
tunes without words, and words and tunes combined as an unfamiliar song. Left lobectomy
resulted in impaired recognition of words alone, and right lobectomy resulted in impaired
recognition of tunes alone, but either left or right lobectomy resulted in impaired recognition
of melody combined with words.^55
Several studies have compared local and global aspects of musical information processing
in brain-damaged subjects. (For melody, pitch intervals are local, whereas melodic contour
is global; for temporal patterns, rhythm is local, whereas meter is global.) In one study
of patients with either right or left cerebral stroke, right hemispheric damage produced
difficulty recognizing changes in either interval or contour, whereas left hemispheric damage
produced difficulty only with intervals; either right or left hemispheric damage produced
difficulty with rhythm but not with meter.^56 By contrast, although a similar study of patients
following right or left cerebral corticectomy found comparable abnormalities involving
interval and contour, either right or left hemispheric damage produced difficulty with meter,
not rhythm.^57 In another study of patients with cerebral strokes, of eight patients with
right-sided damage, five had impaired musical processing; of 12 patients with left-sided
damage, nine had impaired musical processing. Right hemispheric damage caused abnormal
processing of both contour and interval and of both meter and rhythm, whereas left hemi-
spheric damage caused much more variable abnormalities: contour and interval could
be affected alone or in combination, and meter and rhythm could be affected alone or in
combination.^58
Normal subjects recognize pitch even when the fundamental is missing if overtones are
retained. This ability is lost following right temporal lobe damage that includes Heschl’s
gyrus.^59 Another study assessed the ability to recognize timbre derived either from spectral
envelopes or from onset-offset times, and it was found that right temporal lobectomy
produced greater impairment in either ability than did left temporal lobectomy.^60
Following right but not left temporal lobectomy, patients had difficulty reproducing
auditory but not visual rhythm; lesions producing such impairment encroached on the
primary auditory cortex.^61
In normal subjects the harmonic context established by a prime chord influences judg-
ments of target chord intonation; in patients who had undergone corpus callostomy, this
normal interaction was preserved in the right cerebral hemisphere but not the left.^62Studies of normal subjects
Paralleling clinical case reports and studies of brain-damaged subjects have been studies
of musical processing in normal people. Space does not allow a detailed review of such186 Zat-Ch12.qxd 6/6/03 3:43 AM Page 186