Behavioral preferences for consonance over dissonance were tested in hearing infants of deaf parents and in hearing infants of hearing parents when they were 2 days old. Using a modified visual-fixation-based, auditory-preference procedure, I found that both 2-day-old infants of deaf parents and those of hearing parents looked longer at a visual stimulus when looking produced the original version of a Mozart minuet as opposed to a version altered to contain many dissonant intervals. The relative magnitude of such preference did not significantly differ whether their parents were deaf or hearing. Infants prefer consonance over dissonance, and the preference is present from birth and is not dependent on any specific prenatal or early postnatal experience.

Accumulated evidence indicates that cannabidiol (CBD), a nonpsychotomimetic and nonaddictive main component of the Cannabis sativa plant, reverses anxiety-like behavior. The purpose of the present study was to assess the efficacy of CBD treatment for Japanese late teenagers with social anxiety disorder (SAD). Thirty-seven 18–19-year-old Japanese teenagers with SAD and avoidant personality disorder received, in a double-blind study, cannabis oil (n = 17) containing 300 mg CBD or placebo (n = 20) daily for 4 weeks. SAD symptoms were measured at the beginning and end of the treatment period using the Fear of Negative Evaluation Questionnaire and the Liebowitz Social Anxiety Scale. CBD significantly decreased anxiety measured by both scales. The results indicate that CBD could be a useful option to treat social anxiety.

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.

No abstract

Mother-infant vocal interactions play a crucial role in the development of human language. However, comparatively little is known about the maternal role during vocal development in nonhuman primates. Here, we report the first evidence of mother-daughter vocal interactions contributing to vocal development in gibbons, a singing and monogamous ape species. Gibbons are well known for their species-specific duets sung between mates, yet little is known about the role of intergenerational duets in gibbon song development. We observed singing interactions between free-ranging mothers and their sub-adult daughters prior to emigration. Daughters sang simultaneously with their mothers at different rates. First, we observed significant acoustic variation between daughters. Co-singing rates between mother and daughter were negatively correlated with the temporal precision of the song’s synchronization. In addition, songs of daughters who co-sang less with their mothers were acoustically more similar to the maternal song than any other adult female’s song. All variables have been reported to be influenced by social relationships of pairs. Therefore those correlations would be mediated by mother-daughter social relationship, which would be modifiable in daughter’s development. Here we hypothesized that daughters who co-sing less often, well-synchronize, and converge acoustically with the maternal acoustic pattern would be at a more advanced stage of social independence in sub-adult females prior to emigration. Second, we observed acoustic matching between mothers and daughters when co-singing, suggesting short-term vocal flexibility. Third, we found that mothers adjusted songs to a more stereotyped pattern when co-singing than when singing alone. This vocal adjustment was stronger for mothers with daughters who co-sang less. These results indicate the presence of socially mediated vocal flexibility in gibbon sub-adults and adults, and that mother-daughter co-singing interactions may enhance vocal development. More comparative work, notably longitudinal and experimental, is now needed to clarify maternal roles during song development.

In the present study, eight children with Williams syndrome were observed every 2 weeks between 6 months and 30 months of age when interacting with their mothers. When the collected data were transcribed in terms of both linguistic and motor activities, overall delay was found in terms of the onset of canonical babbling, first words, as well as various motor milestones in every child. The degree to which acquisition of each of the milestones was delayed was individually variable. Nevertheless, the onset of hand banging was found to be an indicator that predicted the onset of canonical babbling consistently among the children. Once canonical babbling was produced, moreover, the onset of first words was recorded during a following 2 to 3 month period. These findings appear to indicate the possibility that development of the motor ability to perform such rhythmic motor activity as hand banging acted as a control parameter for production of canonical syllables in the children.

L. J. Trainor (1996) reported preferences for infant-directed versus infant-absent singing in English in 4-7-month-old hearing infants of English-speaking hearing parents. In this experiment, the author tested preferences for infant-directed singing versus adult-directed singing in 15 two-day-old hearing infants of deaf parents for a Japanese and an English play song. Using a modified visual-fixation-based auditory-preference procedure, the author found that infants looked longer at a visual stimulus when looking produced infant-directed singing as opposed to adult-directed singing. These results suggest that infants prefer infant-directed singing over adult-directed singing and that the preference is present from birth and is not dependent on any specific prenatal or postnatal experience.

The Onset of Language outlines an approach to the development of expressive and communicative behaviour from early infancy to the onset of single word utterances. Nobuo Masataka's research is rooted in ethology and dynamic action theory. He argues that expressive and communicative actions are organized as a complex and cooperative system with other elements of the infant's physiology, behaviour and the social environments. Overall, humans are provided with a finite set of specific behaviour patterns, each of which is phylogenetically inherited as a primate species. However, the patterns are uniquely organized during ontogeny and a coordinated structure emerges which eventually leads us to acquire language. This fascinating book offers exciting insights into the precursors of speech and will be of interest to researchers and students of psychology, linguistics and animal behaviour biology.