Laurel J. Trainor

Relations among Musical Skills, Phonological Processing, and Early Reading Ability in Preschool Children.

We examined the relations among phonological awareness, music perception skills, and early reading skills in a population of 100 4- and 5-year-old children. Music skills were found to correlate significantly with both phonological awareness and reading development. Regression analyses indicated that music perception skills contributed unique variance in predicting reading ability, even when variance due to phonological awareness and other cognitive abilities (math, digit span, and vocabulary) had been accounted for. Thus, music perception appears to tap auditory mechanisms related to reading that only partially overlap with those related to phonological awareness, suggesting that both linguistic and nonlinguistic general auditory mechanisms are involved in reading.

Musical Training Enhances Automatic Encoding of Melodic Contour and Interval Structure

In music, melodic information is thought to be encoded in two forms, a contour code (up/down pattern of pitch changes) and an interval code (pitch distances between successive notes). A recent study recording the mismatch negativity (MMN) evoked by pitch contour and interval deviations in simple melodies demonstrated that people with no formal music education process both contour and interval information in the auditory cortex automatically. However, it is still unclear whether musical experience enhances both strategies of melodic encoding. We designed stimuli to examine contour and interval information separately. In the contour condition there were eight different standard melodies (presented on 80 of trials), each consisting of five notes all ascending in pitch, and the corresponding deviant melodies (20) were altered to descending on their final note. The interval condition used one five-note standard melody transposed to eight keys from trial to trial, and on deviant trials the last note was raised by one whole tone without changing the pitch contour. There was also a control condition, in which a standard tone (990.7 Hz) and a deviant tone (1111.0 Hz) were presented. The magnetic counterpart of the MMN (MMNm) from musicians and nonmusicians was obtained as the difference between the dipole moment in response to the standard and deviant trials recorded by magnetoencephalography. Significantly larger MMNm was present in musicians in both contour and interval conditions than in nonmusicians, whereas MMNm in the control condition was similar for both groups. The interval MMNm was larger than the contour MMNm in musicians. No hemispheric difference was found in either group. The results suggest that musical training enhances the ability to automatically register abstract changes in the relative pitch structure of melodies.

Music acquisition: effects of enculturation and formal training on development

Musical structure is complex, consisting of a small set of elements that combine to form hierarchical levels of pitch and temporal structure according to grammatical rules. As with language, different systems use different elements and rules for combination. Drawing on recent findings, we propose that music acquisition begins with basic features, such as peripheral frequency-coding mechanisms and multisensory timing connections, and proceeds through enculturation, whereby everyday exposure to a particular music system creates, in a systematic order of acquisition, culture-specific brain structures and representations. Finally, we propose that formal musical training invokes domain-specific processes that affect salience of musical input and the amount of cortical tissue devoted to its processing, as well as domain-general processes of attention and executive functioning.

Is Infant-Directed Speech Prosody a Result of the Vocal Expression of Emotion?

Many studies have found that infant-directed (ID) speech has higher pitch, has more exaggerated pitch contours, has a larger pitch range, has a slower tempo, and is more rhythmic than typical adult-directed (AD) speech. We show that the ID speech style reflects free vocal expression of emotion to infants, in comparison with more inhibited expression of emotion in typical AD speech. When AD speech does express emotion, the same acoustic features are used as in ID speech. We recorded ID and AD samples of speech expressing love-comfort, fear, and surprise. The emotions were equally discriminable in the ID and AD samples. Acoustic analyses showed few differences between the ID and AD samples, but robust differences across the emotions. We conclude that ID prosody itself is not special. What is special is the widespread expression of emotion to infants in comparison with the more inhibited expression of emotion in typical adult interactions.

Internalized Timing of Isochronous Sounds Is Represented in Neuromagnetic Beta Oscillations

Moving in synchrony with an auditory rhythm requires predictive action based on neurodynamic representation of temporal information. Although it is known that a regular auditory rhythm can facilitate rhythmic movement, the neural mechanisms underlying this phenomenon remain poorly understood. In this experiment using human magnetoencephalography, 12 young healthy adults listened passively to an isochronous auditory rhythm without producing rhythmic movement. We hypothesized that the dynamics of neuromagnetic beta-band oscillations (∼20 Hz)—which are known to reflect changes in an active status of sensorimotor functions—would show modulations in both power and phase-coherence related to the rate of the auditory rhythm across both auditory and motor systems. Despite the absence of an intention to move, modulation of beta amplitude as well as changes in cortico-cortical coherence followed the tempo of sound stimulation in auditory cortices and motor-related areas including the sensorimotor cortex, inferior-frontal gyrus, supplementary motor area, and the cerebellum. The time course of beta decrease after stimulus onset was consistent regardless of the rate or regularity of the stimulus, but the time course of the following beta rebound depended on the stimulus rate only in the regular stimulus conditions such that the beta amplitude reached its maximum just before the occurrence of the next sound. Our results suggest that the time course of beta modulation provides a mechanism for maintaining predictive timing, that beta oscillations reflect functional coordination between auditory and motor systems, and that coherence in beta oscillations dynamically configure the sensorimotor networks for auditory-motor coupling.

Cortical Plasticity Induced by Short-Term Unimodal and Multimodal Musical Training

Learning to play a musical instrument requires complex multimodal skills involving simultaneous perception of several sensory modalities: auditory, visual, somatosensory, as well as the motor system. Therefore, musical training provides a good and adequate neuroscientific model to study multimodal brain plasticity effects in humans. Here, we investigated the impact of short-term unimodal and multimodal musical training on brain plasticity. Two groups of nonmusicians were musically trained over the course of 2 weeks. One group [sensorimotor-auditory (SA)] learned to play a musical sequence on the piano, whereas the other group [auditory (A)] listened to and made judgments about the music that had been played by participants of the sensorimotor-auditory group. Training-induced cortical plasticity was assessed by recording the musically elicited mismatch negativity (MMNm) from magnetoencephalographic measurements before and after training. SA and A groups showed significantly different cortical responses after training. Specifically, the SA group showed significant enlargement of MMNm after training compared with the A group, reflecting greater enhancement of musical representations in auditory cortex after sensorimotor-auditory training compared with after mere auditory training. Thus, we have experimentally demonstrated that not only are sensorimotor and auditory systems connected, but also that sensorimotor-auditory training causes plastic reorganizational changes in the auditory cortex over and above changes introduced by auditory training alone.

Key membership and implied harmony in Western tonal music : developmental perspectives

We investigated the role of key membership and implied harmony in adults’ and children’s perception of tone sequences. Listeners were evaluated on their ability to detect three types of changes in one note of a well-structured Western tonal melody. In one change (out-of-key) the new note was not in the basis key, in another (out-of-harmony) it was in the key but not in the implied harmony, and in the third (within-harmony) it was in both the key and the implied harmony. Adults and 7-year-olds performed better on the out-of-key and out-of-harmony changes than on the within-harmony change, reflecting their implicit knowledge of key membership and implied harmony. Five-year-olds performed better on the out-of-key change than on the other two changes, reflecting the influence of key membership but not implied harmony. We consider the developmental precedence of key membership over implied harmony in the context of cross-cultural and theoretical perspectives.

Infant preferences for infant-directed versus noninfant-directed playsongs and lullabies

Each of 15 mothers was recorded singing a song of her choice to her 4- to 7-month-old and singing the same song alone. Adult raters were very accurate at distinguishing infant-directed from infant-absent versions, and the former were independently rated as more loving than the latter. Most of the songs were consistently classified as either playsongs or lullabies. The infant-directed playsongs were rated as relatively more rhythmic than the infant-directed lullabies, in comparison to the infant-absent versions. These results suggest that playsongs and lullabies may be distinct and used to communicate different information. Infant preferences were tested for three playsong and three lullaby pairs in a preferential looking paradigm. Infants preferred the infant-directed over infant-absent versions for five of the six pairs. Furthermore, the degree of preference was correlated with the adult ratings of loving tone of voice. The results indicate that mothers modify their singing in the presence of their infants, that infants attend to these changes, that playsongs and lullabies are likely distinct musical styles differing in their rhythmic quality, and that what adults perceive to be a loving tone of voice is highly salient to infants.

Automatic and Controlled Processing of Melodic Contour and Interval Information Measured by Electrical Brain Activity

Most work on how pitch is encoded in the auditory cortex has focused on tonotopic (absolute) pitch maps. However, melodic information is thought to be encoded in the brain in two different relative pitch forms, a domain-general contour code (up/down pattern of pitch changes) and a music-specific interval code (exact pitch distances between notes). Event-related potentials were analyzed in nonmusicians from both passive and active oddball tasks where either the contour or the interval of melodyfinal notes was occasionally altered. The occasional deviant notes generated a right frontal positivity peaking around 350 msec and a central parietal P3b peaking around 580 msec that were present only when participants focused their attention on the auditory stimuli. Both types of melodic information were encoded automatically in the absence of absolute pitch cues, as indexed by a mismatch negativity wave recorded during the passive conditions. The results indicate that even in the absence of musical training, the brain is set up to automatically encode music-specific melodic information, even when absolute pitch information is not available.

Beta and gamma rhythms in human auditory cortex during musical beat processing.

We examined β‐ (∼20 Hz) and γ‐ (∼40 Hz) band activity in auditory cortices by means of magnetoencephalography (MEG) during passive listening to a regular musical beat with occasional omission of single tones. The β activity decreased after each tone, followed by an increase, thus forming a periodic modulation synchronized with the stimulus. The β decrease was absent after omissions. In contrast, γ‐band activity showed a peak after tone and omission, suggesting underlying endogenous anticipatory processes. We propose that auditory β and γ oscillations have different roles in musical beat encoding and auditory–motor interaction.