The Cognitive Neuroscience of Music

melodies, adults are thought to encode and retain precise pitch distances between tones

(i.e. intervals) but not the absolute pitches.^62 There are indications, however, that even

untrained adults retain the pitch level of familiar music, as reflected in their reproduction

of familiar pop songs within two semitones of the original recordings.^63 More compelling

evidence of the encoding of absolute pitch cues comes from adults’ ability to distinguish

the original pitch level of television soundtracks from versions that are pitch shifted by as

little as a semitone.^64

Despite infants’ contour processing bias,^29 they can extract detailed interval information

from patterns that elicit enhanced pitch processing in adults. For example, infants detect

interval changes in brief melodies that conform to the conventions of their culture-to-be,

but they fail to do so for melodies that violate those conventions.65– 68It is highly unlikely

that 6-month-old infants have acquired such musical knowledge. Indeed, the available

evidence indicates that 6- to 10-month-old infants lack implicit knowledge of Western

musical conventions.61,69,70The mistaken impression that they are sensitive to these con-

ventions arises from commonalities in musical structure across cultures.49,50

In studies of infant melody perception, the presence of a prominent seven-semitone

interval, or perfect fifth, has been associated with success in interval discrimination, and its

absence with failure.65–68,71The perfect fifthis not alone in enhancing infants’ perception of

pitch relations.^72 Rather, infants, children, and adults detect interval changes more easily in

the context of small-integer ratios—the octave (2 : 1),perfect fifth(3 : 2), and perfect fourth

(4 : 3)—than in the context of large-integer ratios such as the tritone(45 : 32 ratio).72– 74

For example, Schellenberg and Trehub^72 had 6-month-old infants listen to a repeating tone

sequence consisting of alternating tones separated by a perfect fifth(seven semitones),

perfect fourth(five semitones), or tritone(six semitones). Their task was to respond (i.e. by

turning) whenever a semitone change occurred. As can be seen in Figure 1.1, they

succeeded when the standard pattern was consonant (i.e.perfect fourthor fifth) but not

when it was dissonant (i.e.tritone). The implication is that perfect fifthsand fourthsare

6     

3:2 45:32 4:3

Condition

Mean

d

0.5

0.4

0.3

0.2

0

0.1

Figure 1.1 Infant discrimination (d) scores as a function of the frequency ratios of tones in melodic
(sequential) intervals. Figure reprinted from Schellenberg and Trehub^72 with permission. Error bars indicate
standard errors.