The vocal developmental process during the prelinguistic period in Japanese infants has not yet been clarified in detail. The purpose of this study was to clarify the characteristics of vocal development during the prelinguistic period in Japanese infants. The subjects were five Japanese infants. Vocalizations were collected monthly from four to ten months of age, and auditory evaluation was performed by two experienced listeners. We examined the following points regarding Japanese- and English-speaking infants: (i) the correspondence between developmental stage and stage model, (ii) the degree of overlap in cases where staging is possible, (iii) the degree of difference in developmental stage between individuals, and (iv) the relationship between feeding and vocalization. The results showed that canonical babbling appeared prior to vowel-like sounds and vocal play sounds, indicating that developmental stages exist, though there is an overlap between stages. Furthermore, the types and frequency of vocalizations also varied among the infants. Raspberry sounds (RSP) increased in association with the start of feeding with baby food, suggesting that there is a relationship between the appearance of RSP and feeding function.
This study employs magnetic resonance imaging (MRI) techniques to construct anatomical images to facilitate understanding of motor function of the oropharyngeal region. MRI data were acquired in the sagittal, coronal and transverse planes under four imaging conditions (in-phase and opposed-phase conditions in field echo sequence, T1-weighted and proton-density-weighted conditions in spin echo sequence). MRI-RGB representations of the oropharyngeal region are established by the composition of red, blue and green channels using three types of images with different tissue contrasts. In those images, the extrinsic tongue muscles and part of the jaw muscles were recognizable. One of the intrinsic muscles, the vertical muscle, was not confirmed. Other intrinsic tongue muscles (superior longitudinal, inferior longitudinal, and transverse muscle) were partly observed including the surrounding adipose tissue. Anatomical visualization of the oropharyngeal region and its morphological construction in vivo will be useful for studies of speech, deglutition and respiration.
The present study investigated subjective anxiety, stuttering rate, speech rate, vowel space, F1/F2 values and CD/GA values of vowels in a reading task under high and low anxiety conditions controlled by the presence or absence of an audience. Participants were 10 persons who stutter (PWS) and 10 persons who do not stutter (PNS). The PWS group showed higher anxiety than the PNS group under both conditions, reduction of vowel space under the high anxiety condition (a noticeable centralization of F1 /a/ and F2 /i/), higher CD values for /a/, lower CD values for /i/, and lower GA values for /i/. Furthermore, stuttering rates increased significantly. These findings suggest that increases in subjective anxiety induce changes in vowel space and a higher stuttering rate.
We investigated length effect on the reading of Kana words/nonwords in eight children with normal reading ability and seven children with developmental dyslexia. Participants in this study were all Japanese-speaking children in the fifth or sixth grade. Under all word and nonword conditions, reading latency was significantly longer in the dyslexic group than in the control group, while the error rate did not differ between the two groups. Both groups showed main effects of length and lexicality. The control group revealed a significant interaction between length and lexicality, that is, a larger length effect for nonwords than for words, but the dyslexic group did not show such interaction. These results suggested that the fifth and sixth grade primary school children with developmental dyslexia in this study could read neither Kana words nor nonwords fluently. Children with developmental dyslexia appear to fail in the transition from a sub-lexical to a lexical procedure. Furthermore they revealed a capacity to use non-lexical processing but not in a fluent way. These findings suggest that reading speed deficit results from problems in both lexical and non-lexical processing.
Investigations of factors relating to recovery from childhood stuttering are usually based on univariate analysis. Due to this, these factors may not be properly understood, because the relationship between a specific characteristic and recovery from stuttering may be confounded by other factors, or because the relationship between a characteristic and recovery may differ according to whether the subject possesses another factor concurrently. We conducted a longitudinal study of stuttering children who received treatment at stuttering treatment facilities and performed a multivariate analysis by sex and time from onset. We examined the associations between recovery and pre-treatment characteristics by following 97 stuttering children (average age at first consultation at a research institute, 55.7 months; range, 24-111 months) who received stuttering treatment from speech-language-hearing therapists in 14 stuttering treatment facilities. The average time from onset until recovery or end of observation was 36.0 months (range, 5-83 months). Characteristics associated with recovery from stuttering on univariate analysis were simultaneously entered into a proportional hazards model. In this model, stuttering developmental phase was identified as a factor independently related to recovery on analysis of all subjects and analysis by sex. On analysis by time from onset, pre-treatment characteristics were associated with recovery only in the group that received consultations at a stuttering treatment facility within 24 months of onset. An onset age of 24 months or earlier, female sex and a stuttering developmental phase of 1 were found to be associated with a high recovery rate in a mutually independent manner. The period when predictive factors of stuttering recovery can be observed is within 24 months of onset; prognosis for stuttering treatment begun within this time frame can be predicted based on onset age, sex, and pre-treatment developmental phase.
We undertook auditory and language training for a hearing-impaired young child suspected to have attention deficit/hyperactivity disorder (AD/HD). In this training, carried out between the ages of 3 and 6, we analyzed the therapist's approach and adjustment adapted to meet the child’s AD/HD cognitive and behavioral needs as compared with two hearing-impaired young children of the same age without AD/HD. The results suggested that an early approach and adjustment which addresses the cognitive and behavioral needs of AD/HD are effective, in addition to management of the hearing loss. Particularly in the case under study, the following appeared to be useful for the subject’s characteristic inattention behavior: 1) a structured learning procedure, involving initial provision of a task schedule and signals, and setting of goals at the end; 2) proactive adjustment for the content and difficulty of the task and the time available; 3) use of visual aids and provision of inflective and emotional feedback; 4) competition against the therapist or role reversal; 5) commanding the child’s attention using physical cues such as gestures or pointing and lightly touching the body while talking.