1 III II:
A: E%pr#piaol6n de lea terrenoa neeeaariea para la oonatruoclfn de la.a ima talaelenea de la eapreaa,
The understanding of musical development has been revolutionized by the de-velopment of experimental methods for testing the knowledge of very young babies, who are unable to talk or follow instructions. For instance, researchers are able to measure subtle changes in body movement (head or eye turns, rate of sucking) or internal processes (heart rate) that demonstrate a baby’s aware-ness of change. There are now many demonstrations that infant music percep-tion is far more sophisticated than overt behavior would suggest. Only carefully constructed experiments can elicit the full extent of these perceptual abilities, which would normally go unnoticed even by the most observant parent.
Innovative techniques have been able to establish that musical sensitivity and learning exists prior to birth. For example, newborn babies respond with greater attention to music tracks that were repeatedly played by their mothers 26 Musical Learning
before birth than to novel melodies (Hepper, 1991). This means that babies have already picked up and stored quite specific information about the music around them prior to birth. This becomes possible because the auditory system appears to be fully developed by the end of the fourth month of pregnancy (Lecanuet, 1996).
Turning to the months following birth, researchers have shown that 5-month-old babies are already more sensitive to melodic pattern or contour than to pitch as such (see Trehub & Trainor, 1993, for a review). When a melodic pattern to which the babies had become familiarized was transposed up or down by 3 semitones, there was relatively little response. However, when the pattern itself was changed, this provoked strong reaction. Already at 5 months, babies attach relatively little importance to the absolute pitch at which they hear a melody. What is more important to them is the invariant set of contours and in-tervals that distinguish one melody from another. In this respect, babies display musical “intelligence” that older children or even adults show.
Babies also appear to be sensitive to certain aspects of musical structure.
Jusczyk and Krumhansl (1993) showed that babies prefer tonal melodies in which pauses are introduced at the end of phrases rather than the same melodies with pauses occurring at other points. Trainor and Trehub (1993) trained 9-month-old babies to respond to an intensity change in a series of repeating melodic fragments. When the intensity increased, babies were rewarded if they turned their heads at least 45 degrees to the left. The reward was a brief illumi-nation of four lights and a set of mechanical toys. Previous research had shown that the opportunity to look at interesting moving objects is rewarding for ba-bies of this age. Figure 2.1 shows an example of a typical experimental envi-ronment for testing infant perception.
The test phase used a repeating five-note pattern. The background pattern could be either (1) a major triad (e.g., C E G E C) or (2) an augmented triad (e.g., C E G# E C). Each repetition of this pattern began on a different pitch, which meant that only relative pitch information was available to the baby. A
“change trial” occurred when the third note of the pattern was lowered by a semitone; thus (1) would become C E F# E C and (2) would become C E G E C.
The experiment was carried out using both babies and adults (adults signaled a change trial by raising their hands). The proportion of trials in which partici-pants correctly detected a change was recorded. Figure 2.2 shows the percent-age scores for adults and infants, given separately for the major triads and the augmented triads. This shows that adults and infants performed very similarly.
Both groups performed well on the major triads but much more poorly on the augmented triads.
The authors concluded that there is some special feature of a major triad that allows babies (and adults) to process and store it more efficiently. A major fifth is more consonant (having a simpler frequency ratio) than an augmented fifth. It Development 27
28 Musical Learning
Ti ti ti ti
M E
C
M E
C
S Habituation
Ta ta ta
S
S Change
M E
C
Ta ta ta
Reward
Figure 2.1. Schematic diagram of a typical experimental environment for testing in-fants’ perceptual capacities. The child (C) sits on its mother’s (M) lap and hears a stimu-lus from a loudspeaker (S). The experimenter (E) watches the child. Once the child loses interest in the new stimulus and habituates (top panel), the stimulus changes (middle panel). Renewed interest in the changed stimulus is rewarded by lights or a toy (lower panel), and a new trial begins.
also occurs more often in music. Nine-month-old babies have a surprisingly adult capacity to make use of these special features. These and similar studies show that in many respects human babies are “pretuned” to music, able to extract key information necessary for perception and memory of the complex melodic and rhythmic sequences that make up music.
Babies are not simply passive recipients of musical information. The early use of their voices also shows their musical capacities. Long before they are able to produce recognizable words or tunes, babies experiment with their voices, playing with the elements that will later be incorporated in speech and in singing. This activity is called
babbling
and includes cooing, gliding, and the repetition of specific pitch and vowel-consonant patterns (e.g., “da-da-da”).Much of this experimentation takes place in the context of interactions between the infant and the caregiver (usually the mother). Adults interacting with babies alter their vocalizations in very specific ways. This “infant-directed speech” is more rhythmical and songlike than normal speech, uses affective archetypes, and imitates specific features of vocalizations of the infant in order to attract the Development 29
Adults
t c
e r r o c t n e c r P e
0.0 0.2 0.4
Maj-P5
0.6 0.8 1.0
Infants
Aug-Aug5
Figure 2.2. Percent correct performance for infants and adults in Trainor and Trehub’s (1993) experiment. The bars show performance for the major chord and for the aug-mented chord. From “What Mediates Infants’ and Adults’ Superior Processing of the Major over the Augmented Triad?” by L. J. Trainor & S. E. Trehub, 1993, Music Percep-tion, 11, p. 190, Figure 1. Copyright © 1993 by the Regents of the University of Califor-nia. Reproduced with permission.
infant’s attention (Papousek, 1996). The imitation is two way: Infants also imi-tate pitches and melodic contours that they hear in adult speech (Kessen, Levine,
& Wendrich, 1979). Some of these skills are apparent well before 6 months of age. Babies are much more attentive to mothers singing than to mothers speak-ing the same text (Trehub, 2003). When mothers sspeak-ing to their babies, they use raised pitch level, decreased tempo, and a more emotive voice quality. Music is thus an essential part of babies’ behavior and interaction from the very begin-ning of life.
All the evidence we have demonstrates that babies can do quite sophisticated things musically. This is very strong backing for the conclusion that musical ca-pacity is a universal inherent human caca-pacity: It is part of what it means to be human. The achievements just described are not the achievements of “su-perbabies”—they are what every average baby achieves. Indeed, the literature on infant capacity is notable for the absence of studies demonstrating large and systematic individual differences between babies in their musical capacities.
Even studies that have specifically searched for early signs of difference be-tween able and less able young musicians have failed to find consistent evi-dence that high achievers were exceptional babies, musically speaking (Howe, Davidson, Moore, & Sloboda, 1995). Of course, in any given study, babies’ re-sponses do differ, but many of these differences are more likely to be caused by differences in attentiveness and arousal than differences in underlying capacity.
We know of no studies on babies in which individual differences in response have been linked to long-term differences in musical ability or achievement.
If music is a universal capacity of the human brain, it is important to ask whether anything could ever go wrong with a brain to render it incapable of dealing with music. We know from some astonishing life histories (e.g., the per-cussionist Evelyn Glennie) that even profound deafness does not automatically exclude high levels of musical achievement. The prime contender for a “brain-disabling” condition is congenital amusia (see Peretz & Hyde, 2003, for a review; see chapter 11). This condition (sometimes self-diagnosed as “tone deafness”) afflicts about 4% of the population to a greater or lesser extent (Kalmus & Fry, 1980). People with congenital amusia have long-standing defi-ciencies in detecting pitch and rhythm changes in melodies, even though their speech and hearing is normal. This means that they fail on simple musical tasks (such as telling two melodies apart) on which most musically untrained adults are able to perform perfectly. Psychometric tests now exist to identify and pin-point the nature of amusic deficiencies, but we still do not understand the precise neurological underpinnings of this condition, nor has anyone yet identified a congenitally amusic baby. It still remains possible that amusia is acquired during or after infancy rather than being a genetically determined deficiency. Whatever the final outcome of research into congenital amusia, we can already be fairly certain that at least 96% of the general population has the innate capacity to deal with music.
30 Musical Learning