The Role of Letter-Speech Sound Integration in Native and Second Language Reading: A Study in Native Japanese Readers Learning English.

The automatic activation of letter-speech sound (L-SS) associations is a vital step in typical reading acquisition. However, the contribution of L-SS integration during nonalphabetic native and alphabetic second language (L2) reading remains unclear. This study explored whether L-SS integration plays a similar role in a nonalphabetic language as in alphabetic languages and its contribution to L2 reading among native Japanese-speaking adults with varying English proficiency. A priming paradigm in Japanese and English was performed by presenting visual letters or symbols, followed by auditory sounds. We compared behavioral and event-related responses elicited by congruent letter-sound pairs, incongruent pairs, and baseline condition (symbol-sound pairs). The behavioral experiment revealed shorter RTs in the congruent condition for Japanese and English tasks, suggesting a facilitation effect of congruency. The ERP experiment results showed an increased early N1 response to Japanese congruent pairs compared to corresponding incongruent stimuli at the left frontotemporal electrodes. Interestingly, advanced English learners exhibited greater activities in bilateral but predominantly right-lateralized frontotemporal regions for the congruent condition within the N1 time window. Moreover, the enhancement of P2 response to congruent pairs was observed in intermediate English learners. These findings indicate that, despite deviations from native language processing, advanced speakers may successfully integrate letters and sounds during English reading, whereas intermediate learners may encounter difficulty in achieving L-SS integration when reading L2. Furthermore, our results suggest that L2 proficiency may affect the level of automaticity in L-SS integration, with the right P2 congruency effect playing a compensatory role for intermediate learners.

Lexical prosodic representation and access in Japanese children with developmental dyslexia.

Recent research indicates that awareness of the prosodic information present in spoken language could be an important factor for literacy development, and that adults with developmental dyslexia show impaired awareness of lexical prosodic information, while the phonological representations remain intact. We investigated lexical prosodic representation and awareness in Japanese children with and without developmental dyslexia. Lexical prosodic representation was investigated using a cross-modal fragment priming task, and awareness was examined using a fragment identification task. The task was modified for children by selecting words with higher familiarity and fewer trials. As a result, the same pattern of prosodic priming effects was observed between groups; lexical decision time was faster in the prosodic congruent condition than in the incongruent condition. In addition, accuracy and reaction time did not show group differences in the fragment identification task. Relationship between prosody and literacy development may differ between languages but the sample size were small in both groups. Further investigation with larger sample size is required.

Development of a reading difficulty questionnaire for adolescents in Japanese.

BACKGROUND: Dyslexia is a neurodevelopmental disorder which occurs in childhood but continues to influence academic and occupational function in adulthood. Recently, a Japanese dyslexia questionnaire and diagnostic procedure was established for primary school children. However, there is currently no procedure for the diagnosis or screening of dyslexia in individuals at or above junior high school age; accordingly, we aimed to develop a questionnaire to screen for reading difficulties in those individuals. METHODS: A questionnaire with various candidate items was developed from two English questionnaires, one Japanese questionnaire, and newly devised items focusing on the Japanese writing system and the most appropriate 28 items were selected. In total, 462 adults and 127 junior high to high school students were enrolled. Of those, 191 participants also took part in reading tests. After the exploratory factor analysis, reliability and validity were evaluated using the above control participants and 12 adolescents with dyslexia. RESULTS: The questionnaire included three factors, i.e., silent reading sub-scale (four items), writing sub-scale (four items), and aloud reading sub-scale (three items). Five were newly devised items focusing on the Japanese writing system. Cronbach's alphas of the three factors were 0.706, 0.638, and 0.568, respectively, and the interclass correlation coefficients (2,1) were 0.743, 0.609, and 0.695, respectively. The silent reading and aloud reading sub-scales were positively correlated with word, non-word, and passage reading time. DISCUSSION: The newly developed questionnaire correlated well with actual reading performance and may be used to screen reading difficulty in Japanese individuals at or above junior high school age.

Differences between children and adults in functional connectivity between the inferior frontal gyrus and extrastriate body area for gestural interaction.

Gestural interaction, where a person initiates interaction (initiator) and another person responds to it (follower), changes during development. The neural network comprising the inferior frontal gyrus (IFG), inferior parietal lobule (IPL), and the lateral occipito-temporal cortex (LOTC) is relevant to gestural interaction. The LOTC includes the extrastriate body area (EBA). Activation of these brain regions depends on the initiating/following role in adults. We conducted functional magnetic resonance imaging study on 18 children and 18 adults, to elucidate developmental changes of the neural mechanism underlying gestural interaction. We manipulated the initiating/following role (initiating/following) and congruency (congruent/incongruent) of executed and observed actions. After analyzing regional brain activity, we assessed psycho-physiological interaction to examine functional connectivity. Activation in the IFG and connectivity between the IFG and EBA in the Initiating rather than Following condition, which might be associated with evaluating social relevance, was stronger in adults than in children. The increase of the incongruency effect in the following condition (relative to the initiating condition) in the bilateral IPL was significantly attenuated in children compared with adults. These results suggest that the fronto-parieto-temporal network, involved in gestural interactions, undergoes developmental changes.

Age-dependent atypicalities in body- and face-sensitive activation of the EBA and FFA in individuals with ASD.

Individuals with autism spectrum disorder (ASD) have difficuly in recognizing bodies and faces, which are more pronounced in children than adults. If such difficulties originate from dysfunction of the extrastriate body area (EBA) and the fusiform face area (FFA), activation in these regions might be more atypical in children than in adults. We preformed functional magnetic resonance imaging while children and adults with ASD and age-matched typically developed (TD) individuals observed face, body, car, and scene. To examine various aspects, we performed individual region of interest (ROI) analysis, as well as conventional random effect group analysis. At individual ROI analysis, we examined the ratio of participants showing a category-sensitive response, the size of regions, location and activation patterns among the four object categories. Adults with ASD showed no atypicalities in activation of the EBA and FFA, whereas children with ASD showed atypical activation in these regions. Specifically, a smaller percentage of children with ASD showed face-sensitive activation of the FFA than TD children. Moreover, the size of the EBA was smaller in children with ASD than in TD children. Our results revealed atypicalities in both the FFA and EBA in children with ASD but not in adults with ASD.

Sleep is associated with offline improvement of motor sequence skill in children.

In adults, sleep is necessary for the offline improvement of certain skills, such as sequential finger tapping, but whether children show a similar effect is still debatable. Here, we tested whether sleep is associated with offline performance improvement in children. Nine- and 11-year-old children trained on an explicit sequential finger tapping task. On the night following training, their parents observed and recorded the duration of each child's sleep. The following day, all children performed a surprise retest session on the previously trained sequence. In both 9- and 11-year-old children, skill performance was significantly improved during the first retest session relative to the end of training on the previous day, confirming the offline improvement in performance. There was a significant correlation between the degree of improvement and sleep duration the night after training, suggesting that in children, as in adults, sleep is associated with offline skill enhancement.

[Early detection of specific reading disorder through response to intervention:a cohort study].

OBJECTIVE: The present study examined the effectiveness of response to intervention (RTI) for the early detection and intervention for specific reading disorder. METHOD: RTIs were applied to seventy-seven first graders (36 boys and 41 girls) for the early detection and intervention of specific reading disorders. The outcomes were examined when the children reached the third grade. RESULTS: Reading difficulties were detected in four children at the beginning of the first grade. Decoding training and vocabulary learning were conducted with these children as interventions for reading difficulties. Three children exhibited improvements in reading difficulties at the end of the first grade. The fourth child responded poorly and was diagnosed with specific reading disorder. The assessment of outcomes at the third grade showed that this child still had reading difficulties, whereas no other child displayed symptoms for being diagnosed with specific reading disorder. CONCLUSION: RTI is effective for the early detection and intervention of specific reading disorder.

Structural brain differences in school-age children with residual speech sound errors.

The purpose of the study was to identify structural brain differences in school-age children with residual speech sound errors. Voxel based morphometry was used to compare gray and white matter volumes for 23 children with speech sound errors, ages 8;6-11;11, and 54 typically speaking children matched on age, oral language, and IQ. We hypothesized that regions associated with production and perception of speech sounds would differ between groups. Results indicated greater gray matter volumes for the speech sound error group relative to typically speaking controls in bilateral superior temporal gyrus. There was greater white matter volume in the corpus callosum for the speech sound error group, but less white matter volume in right lateral occipital gyrus. Results may indicate delays in neuronal pruning in critical speech regions or differences in the development of networks for speech perception and production.

Altered brain activity for phonological manipulation in dyslexic Japanese children.

Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children.

[Efficacy of decoding training for children with difficulty reading hiragana].

OBJECTIVE: The present study aimed to clarify the efficacy of decoding training focusing on the correspondence between written symbols and their readings for children with difficulty reading hiragana (Japanese syllabary). METHODS: Thirty-five children with difficulty reading hiragana were selected from among 367 first-grade elementary school students using a reading aloud test and were then divided into intervention (n=15) and control (n=20) groups. The intervention comprised 5 minutes of decoding training each day for a period of 3 weeks using an original program on a personal computer. Reading time and number of reading errors in the reading aloud test were compared between the groups. RESULTS: The intervention group showed a significant shortening of reading time (F(1,33)=5.40, p<0.05, two-way ANOVA) compared to the control group. However, no significant difference in the number of errors was observed between the two groups. Ten children in the control group who wished to participate in the decoding training were included in an additional study;as a result, improvement of the number of reading errors was observed (t= 2.863, p< 0.05, paired t test), but there was no improvement in reading time. CONCLUSIONS: Decoding training was found to be effective for improving both reading time and reading errors in children with difficulty reading hiragana.

A study of the standard brain in Japanese children: morphological comparison with the MNI template.

Functional magnetic resonance imaging (MRI) studies involve normalization so that the brains of different subjects can be described using the same coordinate system. However, standard brain templates, including the Montreal Neurological Institute (MNI) template that is most frequently used at present, were created based on the brains of Western adults. Because morphological characteristics of the brain differ by race and ethnicity and between adults and children, errors are likely to occur when data from the brains of non-Western individuals are processed using these templates. Therefore, this study was conducted to collect basic data for the creation of a Japanese pediatric standard brain. Participants in this study were 45 healthy children (contributing 65 brain images) between the ages of 6 and 9 years, who had nothing notable in their perinatal and other histories and neurological findings, had normal physical findings and cognitive function, exhibited no behavioral abnormalities, and provided analyzable MR images. 3D-T1-weighted images were obtained using a 1.5-T MRI device, and images from each child were adjusted to the reference image by affine transformation using SPM8. The lengths were measured and compared with those of the MNI template. The Western adult standard brain and the Japanese pediatric standard brain obtained in this study differed greatly in size, particularly along the anteroposterior diameter and in height, suggesting that the correction rates are high, and that errors are likely to occur in the normalization of pediatric brain images. We propose that the use of the Japanese pediatric standard brain created in this study will improve the accuracy of identification of brain regions in functional brain imaging studies involving children.

Functional brain activation differences in school-age children with speech sound errors: speech and print processing.

PURPOSE: To examine neural response to spoken and printed language in children with speech sound errors (SSE). METHOD: Functional magnetic resonance imaging was used to compare processing of auditorily and visually presented words and pseudowords in 17 children with SSE, ages 8;6[years;months] through 10;10, with 17 matched controls. RESULTS: When processing spoken words and pseudowords, the SSE group showed less activation than typically speaking controls in left middle temporal gyrus. They also showed greater activation than controls in several cortical and subcortical regions (e.g., left superior temporal gyrus, globus pallidus, insula, fusiform, and bilateral parietal regions). In response to printed words and pseudowords, children with SSE had greater activation than controls in regions including bilateral fusiform and anterior cingulate. Some differences were found in both speech and print processing that that may be associated with children with SSE failing to show common patterns of task-induced deactivation and/or attentional resource allocation. CONCLUSION: Compared with controls, children with SSE appear to rely more on several dorsal speech perception regions and less on ventral speech perception regions. When processing print, numerous regions were observed to be activated more for the SSE group than for controls.

Distinction between the literal and intended meanings of sentences: a functional magnetic resonance imaging study of metaphor and sarcasm.

To comprehend figurative utterances such as metaphor or sarcasm, a listener must both judge the literal meaning of the statement and infer the speaker's intended meaning (mentalizing; Amodio and Frith, 2006). To delineate the neural substrates of pragmatic comprehension, we conducted functional magnetic resonance imaging (fMRI) with 20 normal adult volunteers. Participants read short stories followed by a target sentence. Depending on the context provided by the preceding stories, the target sentences were classified as follows: (1) metaphor versus literally coherent; (2) metaphor versus literally incoherent; (3) sarcasm versus literally coherent; and (4) sarcasm versus literally incoherent. For each task pair, we directly compared the activations evoked by the same target sentences in the different contexts. The contrast images were incorporated into a 2 (metaphor and sarcasm)×2 (literal coherency and incoherency) design. Metaphor-specific activation was found in the head of the caudate, which might be involved in associating statements with potential meanings, and restricting sentence meanings within a set of possible candidates for what the speaker intended. Sarcasm-specific activation was found in the left amygdala, which is an important component of the neural substrates of social behavior. Conjunction analysis revealed that both metaphor and sarcasm activated the anterior rostral medial frontal cortex (arMFC), which is a key node of mentalizing. A distinct literal coherency effect was found in the orbital MFC, which is thought to be involved in monitoring. These mesial frontal areas are jointly involved in monitoring literal coherency and mentalizing within social contexts in order to comprehend the pragmatic meanings of utterances.

[Reading aloud as rehabilitation method for children with dyslexia detected at the first grade in their primary school].

We provided reading aloud instructions to a child who was diagnosed with dyslexia in a regular class of 69 first graders, comprising 33 boys and 36 girls, during a test of reading sentences aloud. The instructions consisted of a 2-step approach, i.e., decoding instruction and vocabulary instruction. First, a decoding instruction, which emphasized an important point in effortless decoding, was presented to the child. Next, a vocabulary instruction, which aimed to facilitate word-form recognition, was provided. We found that, the decoding instruction was effective in decreasing the number of reading errors, and that the vocabulary instruction was effective against reducing the time taken to read aloud.

Identifying residual speech sound disorders in bilingual children: a Japanese-english case study.

PURPOSE: To describe (a) the assessment of residual speech sound disorders (SSDs) in bilinguals by distinguishing speech patterns associated with second language acquisition from patterns associated with misarticulations and (b) how assessment of domains such as speech motor control and phonological awareness can provide a more complete understanding of SSDs in bilinguals. METHOD: A review of Japanese phonology is provided to offer a context for understanding the transfer of Japanese to English productions. A case study of an 11-year-old is presented, demonstrating parallel speech assessments in English and Japanese. Speech motor and phonological awareness tasks were conducted in both languages. RESULTS: Several patterns were observed in the participant's English that could be plausibly explained by the influence of Japanese phonology. However, errors indicating a residual SSD were observed in both Japanese and English. A speech motor assessment suggested possible speech motor control problems, and phonological awareness was judged to be within the typical range of performance in both languages. CONCLUSION: Understanding the phonological characteristics of the native language can help clinicians recognize speech patterns in the second language associated with transfer. Once these differences are understood, patterns associated with a residual SSD can be identified. Supplementing a relational speech analysis with measures of speech motor control and phonological awareness can provide a more comprehensive understanding of a client's strengths and needs.

Dyslexia: advances in clinical and imaging studies.

The aim of this report is to describe the characteristics of Japanese dyslexia, and to demonstrate several of our studies about the extraction of these characteristic and their neurophysiological and neuroimaging abnormalities, as well as advanced studies of phonological awareness and the underlying neural substrate. Based on these results, we have proposed a 2-step approach for remedial education (e-learning web site: http://www.dyslexia-koeda.jp/). The first step is decoding, which decreases reading errors, and the second is vocabulary learning, which improves reading fluency. This 2-step approach is designed to serve first grade children. In addition, we propose the RTI (response to intervention) model as a desirable system for remedial education.

Incidental findings of brain magnetic resonance imaging study in a pediatric cohort in Japan and recommendation for a model management protocol.

BACKGROUND: The increasing use of magnetic resonance imaging (MRI) in brain researches has led to growing concern over incidental findings (IFs). To establish a practical management protocol for IFs, it is useful to know the actual prevalence and problems of IF management. In the present study, we report the prevalence proportion and some handling problems of IFs in healthy Japanese children, and suggest a management protocol from ethical and practical standpoints. METHODS: Between 2006 and 2008, 120 healthy children aged 5-8 years participated in a structural MRI study conducted in a pediatric cohort in Japan. All MRI images were reviewed by a pediatric neurologist, and detected IFs were classified into 4 categories. RESULTS: IFs of all categories were detected in 40 of the 110 participants (36.4%) for whom T2-weighted or 3D-T1-weighted images were available. Findings of sinusitis and/or otitis media were most frequent (26.4%). Excluding these findings, the prevalence of IFs was still 10.9% (12 findings): 9 findings were categorized as "no referral" (8.2%), 2 as "routine referral" (1.8%), 1 as "urgent referral" (0.9%), and 0 as "immediate referral" (0.0%). In "routine referral" category, only one participant was referred for further examinations. CONCLUSIONS: Although the prevalence of IFs was high, the proportion of those requiring further examination was low. This result revealed a fairly high false-positive rate and suggested that evaluating equivocal findings was the most difficult part of IF management. A management protocol needs to include a process to properly assess the clinical importance of findings.

Strategies behind the establishment of a developmental cohort study in the Tottori City.

BACKGROUND: The Tottori study group, part of the JCS, presides over a community-based cohort study started when subjects-children living in Tottori City-were 5 years old. The social aspects of conducting a cohort study should also be made public, as this information is crucial for conducting community-based cohort studies. METHODS: Documents pertaining to social aspects implemented by the Tottori study group between 2004 and 2008 were arranged chronologically. Information which is crucial for conducting community-based cohort studies were extracted and classified into several categories. RESULTS: Five categories were extracted from the documents: research staff, supporting committee, recruitment, maintenance of motivation and disclosure. Implementation of the social aspects described in maintenance of motivation resulted in fewer subjects dropping out of the study and a re-recruitment rate of approximately 90%. CONCLUSIONS: The following factors are essential for a successful developmental cohort study of children: 1) A birth cohort study should be planned in hospitals with medical staff such as obstetricians and pediatricians; 2) An interdisciplinary group composed of medical or psychological clinicians and researchers with abundant experience in epidemiological study should be included; 3) If possible, an expert or widely known individual in the study's target field should be included as a member of the study staff; 4) For long cohort studies, a researcher with expertise in school education should be included; 5) A support committee should be organized as an external part of the study team.

Relationship between children's intelligence and their emotional/behavioral problems and social competence: gender differences in first graders.

BACKGROUND: The present study examines gender differences in the correlations between intelligence and developmental problems as well as social competence in first graders. METHODS: Ninety parent-child dyads participated in this study. The children comprised 7-year-olds recruited from the first grade of an elementary school. All the children were administered the Wechsler Intelligence Scale for Children-Third Edition (WISC-III), Parent-child Interaction Rating Scale (IRS), and the parent report version of Strength and Difficulties Questionnaire (SDQ). RESULTS: The findings clarified that the processing speed of boys significantly correlated with their peer relationship. On the other hand, the emotional symptoms exhibited by girls had a more common association with their intellectual abilities. The correlations between parenting and intellectual abilities differed in boys and girls. CONCLUSIONS: Children's gender should be taken into account when assessing the diversity in their intellectual abilities and developmental problems. Moreover, parenting also influences the development of children in various ways.