Co‐occurences of preverbal vocal behavior and motor action in early infancy

Abstract

This study reports on co-occurrence of vocal behaviors and motor actions in infants in the prelinguistic stage. Four Japanese infants were studied longitudinally from the age of 6 months to 11 months. For all the infants, a 40 min sample was coded for each monthly period. The vocalizations produced by the infants co-occurred with their rhythmic actions with high frequency, particularly in the period preceding the onset of canonical babbling. Acoustical analysis was conducted on the vocalizations recorded before and after the period when co-occurrence took place most frequently. Among the vocalizations recorded in the period when co-occurrence appeared most frequently, those that co-occurred with rhythmic action had significantly shorter syllable duration and shorter formant-frequency transition duration compared with those that did not co-occur with rhythmic action. The rapid transitions and short syllables were similar to patterns of duration found in mature speech. The acoustic features remained even after co-occurrence disappeared. These findings suggest that co-occurrence of rhythmic action and vocal behavior may contribute to the infant's acquisition of the ability to perform the rapid glottal and articulatory movements that are indispensable for spoken language acquisition.

Variation in Vocal-Motor Development in Infant Siblings of Children with Autism

“…When systems of this type are coupled, they are typically termed 'coupled oscillators;' and it is a well-established characteristic of coupled oscillators that each tries to draw the other into its characteristic oscillation pattern. This suggests the possibility that entrainment, which occurs when the activation of one oscillator is sufficient to "pull in" the activity of the other to yield an ordered patterning of coordinated activity, may characterize the development of vocal-motor coordination (see Iverson & Fagan, 2004, for discussion and relevant data; see also Ejiri & Masataka, 2001). Iverson and Thelen (1999) characterize the emergence of reduplicated babble as a product of the entrainment of the vocal by the motor system.…”

Infant Vocal–Motor Coordination: Precursor to the Gesture–Speech System?

“…In a longitudinal study, Ejiri and Masataka (2001) examined cooccurrences between vocalization and motor activity in 4 infants observed monthly in naturalistic in-home play sessions between the ages of 6 and 11 months. They coded vocalizations and four types of motor activity (mouthing, manipulating, banging, and rhythmic actions) and noted all instances of co-occurrence between vocal and motor behaviors, defined as a temporal overlap between behaviors of more than 1 s. The authors reported that, in general, a higher percentage of vocalizations co-occurred with rhythmic movements than with other types of motor behaviors.…”

The Influence of Mouthing on Infant Vocalization

“…She interpreted both activities as variants in bringing about vocal tract closure and constriction. In an additional study of 4 infants between 6 and 11 months, Ejiri and Masataka (2001) documented both the frequent occurrence of mouthing and co-occurrences of mouthing and vocalization; however, they did not describe the characteristics of co-occurring vocalizations. Descriptions of vocalizations that co-occur with mouthing may be important for three reasons: Mouthing is an exploratory behavior that may extend to encompass exploration of co-occurring vocalizations; the peak period of mouthing behavior in infancy coincides with and may contribute to advances in consonant production; and mouthing, which appears to contribute to the development of multimodal object perception, may also contribute to the development of multimodal speech perception.…”