Yonata Levy

Accelerated maturation of white matter in young children with autism: A high b value DWI study

The goal of this work was to study white matter maturation in young children with autism following previous reports of increased cerebral volume during early development, as well as arguments for abnormal neural growth patterns and regulation at this critical developmental period. We applied diffusion tensor imaging (DTI) and high b value diffusion-weighted imaging (DWI) to young children diagnosed with autism and to a typically developing (TD) control group. Fractional anisotropy (FA), probability and displacement were measured in overall analysis as well as in regions of interest (ROI). Individual data points of children with autism were compared to the developmental curves obtained from typically developing children. Increased restriction, reflected in significantly increased FA and probability along with reduced displacement values, was detected in overall analysis as well as in several brain regions. Increased restriction, suggesting an early and accelerated abnormal maturation of white matter, was more dominant in the left hemisphere and was mainly detected in the frontal lobe. No changes were detected in the occipital lobes. These results support previous claims of abnormal brain overgrowth in young children with autism and are in contrast to the decreased restricted diffusion reported in previous studies in adolescent with autism.

Abnormal White Matter Integrity in Young Children with Autism

This study investigated white matter integrity in young children with autism using diffusion tensor imaging (DTI). Twenty‐two children with autism, mean age 3:2 years, and 32 controls, mean age 3:4 years, participated in the study. Tract‐based spatial statistics (TBSS) revealed white matter abnormalities in several distinct clusters within the genu and body of the corpus callosum (CC), left superior longitudinal fasciculus (SLF) and right and left cingulum (Cg). TBSS–VOIs analysis was performed in the clusters where differences in fractional anisotropy (FA) were detected to investigate the relationship between changes in FA and diffusivity indices. In all VOIs, increase in FA was caused by a decrease in radial diffusivity (Dr), while no changes in axial diffusivity (Da) or mean diffusivity (MD) were observed. Tractography analysis was applied to further study the CC, SLF, and Cg. Witelson parcellation scheme was used for the CC. Significant increase in FA was seen in children with autism in the mid‐body of the CC as well as in the left Cg. It is suggested that such abnormal white matter integrity in young children with autism may adversely affect connectivity between different brain regions and may be linked to some of the behavioral impairments apparent in autism. Hum Brain Mapp, 2011.

It's frogs all the way down

Abstract This paper challenges the major theoretical motivation underlying a stage-model for language development (Gleitman, 1981), namely, that early grammars are exclusively of a semantic nature. Data concerning the development of gender systems in a variety of languages is presented. Particularly, the development of the use of referential pronouns and inflected verb forms and the role of the animate/inanimate distinction in the development of linguistic gender are seen to involve strictly formal nonsemantic generalizations from their first appearances in childrens language, ages 2 years and on. Early two-word stage grammar cannot then be exclusively ‘semantic’. Since it already involves semantic as well as non-semantic generalizations, the more highly developed grammars of later phases need not trigger any qualitative changes that will warrant a stage model for language development.

The acquisition of Hebrew plurals: the case of the missing gender category.

Childrens acquisition of noun pluralization patterns in Hebrew was studied longitudinally and cross-sectionally. The data show that, through the period of acquisition (age 2–3), children make maximal use of the available morphophonological clues for pluralization; they determine their choice of the plural morpheme according to the nature of the final syllable of the noun singular. They seem totally insensitive to the semantic notion of gender which governs the choice of plurals for animate nouns, as well as to a syntactic notion of gender which in Hebrew determines noun–adjective agreement.

Empty subjects in Finnish and Hebrew

Finnish and Hebrew (in most tenses) share an unusual mixed subject omission pattern: the subject NP is optional in the first and second person but is generally required in the third person. A unified analysis of the two languages is developed in this paper, using certain proposals of Minimalism and a licensing principle which requires that both the specifier and the head position of a projection must be filled. In addition to the null subject pattern, Finnish and Hebrew differ both from traditional pro-drop and from non- pro-drop languages in the patterning of the agreement paradigm; the analysis developed here provides a connection between the mixed null subject pattern and the special agreement paradigm.

Research review: crossing syndrome boundaries in the search for brain endophenotypes.

The inherent imprecision of behavioral phenotyping is the single most important factor contributing to the failure to discover the biological factors that are involved in psychiatric and neurodevelopmental disorders (e.g., Bearden & Freimer, 2006). In this review article we argue that in addition to an appreciation of the inherent complexity at the biological level, a rather urgent task facing behavioral scientists involves a reconsideration of the role that clinical syndromes play in psychological theorizing, as well as in research into the biological basis of cognition and personality. Syndrome heterogeneity, cross-syndrome similarities and syndrome comorbidities question the relevance of syndromes to biological research. It is suggested that the search for brain endophenotypes, intermediate between genes and behavior, should be based on cross-syndrome, trait classification. Cohort selection should rest on behavioral homogeneity, enabling, when necessary, syndrome heterogeneity.

Word reading and reading-related skills in adolescents with Williams syndrome

BACKGROUND Individuals with Williams syndrome have good spontaneous language despite low levels of intelligence. This study explores the relationship between intelligence, word decoding and reading-related skills in 20 individuals with Williams syndrome. METHODS In addition to the KBIT, the participants were administered standardized measures of reading, vocabulary, rapid naming, phonological skills and an experimental measure of rhyme judgement. RESULTS There was wide variability in the reading achievement among the individuals with WS. While some participants were unable to recognize letters of the alphabet, others scored within the normal range of tests of single word reading and decoding. Reading scores were correlated with intelligence as measured on KBIT matrices but not with the vocabulary measures. Reading also correlated with phonological awareness tasks yet, surprisingly, not with rapid naming. CONCLUSION It is suggested that in individuals with retardation, intelligence rather than language and language-related skills predict achievements in word reading.

Interactive Processes in Matching Identity and Expressions of Unfamiliar Faces: Evidence for Mutual Facilitation Effects:

We investigated the interactions between matching identity and expressions of unfamiliar faces. In experiment 1, participants matched expressions in frontal and in oblique views, while we manipulated facial identity. In experiment 2, participants matched identity in frontal and in oblique views, while facial expressions were manipulated. Labeling of expressions was not required. Results showed mutual facilitation between matching facial identity and facial expressions, in accuracy as well as in reaction times. Thus, matching expressions was better and faster for same-identity images in oblique as well as in frontal views (experiment 1), and matching identity was better and faster for same-expression images in oblique as well as in frontal views (experiment 2). The discussion focuses on the implications of these results for the structural encoding of facial identity and facial expressions.

Cognitive, lexical and morpho-syntactic profiles of israeli children with Williams syndrome

This paper investigated the cognitive, lexical and morpho-syntactic profiles of school-age Israeli children with confirmed diagnosis of Williams syndrome (WS). Children with retardation of unknown etiologies were individually matched to the children with WS. The findings suggest a cognitive profile that was similar to the profile reported for English-speaking children with WS, whose unique features were seen mainly in the discrepancy between verbal IQ and performance IQ and in relatively preserved face recognition abilities (Frangiskakis et al., 1996; Mervis et al., 1999). Contrary to previous findings, cognitive, lexical and morpho-syntactic profiles of individual children were rather similar, confirming the findings that were based on matched-pairs comparisons.

Linguistic development of a child with a congenital, localised l.h. lesion

Abstract This paper presents findings from a longitudinal, naturalistic study of knowledge of formal aspects of Hebrew grammar, in a child with a congenital, localised brain-lesion in the left hemisphere. Such knowledge assumes familiarity with aspects of language that are often independent of meaning considerations. The questions that are addressed concern the plasticity of the brain hemispheres early in life. The findings suggest that, with respect to inflectional morphology, and to certain aspects of syntax, the child was developing in a normal way, despite the massive L.H. lesion. This was interpreted as supporting the plasticity model and the “linguistic approach” to language acquisition.