Persistent Neurobehavioral Markers of Developmental Morphosyntax Errors in Adults.

Purpose Child language acquisition is marked by an optional infinitive period (ages 2-4 years) during which children use nonfinite (infinitival) verb forms and finite verb forms interchangeably in grammatical contexts that require finite forms. In English, children's errors include omissions of past tense /-ed/ and 3rd-person singular /-s/. This language acquisition period typically ends by the age of 4 years, but it persists in children with language impairments. It is unknown if adults still process optional infinitives differently than other kinds of morphosyntax errors. Method We compared behavior and functional brain activation during grammaticality judgments across sentences with developmental optional infinitive tense/agreement errors ("Yesterday I play the song"), nondevelopmental agreement errors ("He am tall") that do not occur in typical child language acquisition, and grammatically correct sentences. Results Adults (N = 25) were significantly slower and less accurate in judging sentences with developmental errors relative to other sentences. Sentences with developmental errors yielded greater activation in bilateral inferior frontal gyri relative to nondevelopmental error sentences in both auditory and visual modalities. Conclusions These findings suggest that the heightened computational demands for finiteness extend well beyond early childhood and continue to exert their influence on grammatical mental and brain function in adulthood.

Shared neuroanatomical substrates of impaired phonological working memory across reading disability and autism.

BACKGROUND: Individuals with reading disability or individuals with autism spectrum disorder (ASD) are characterized, respectively, by their difficulties in reading or social communication, but both groups often have impaired phonological working memory (PWM). It is not known whether the impaired PWM reflects distinct or shared neuroanatomical abnormalities in these two diagnostic groups. METHODS: White-matter structural connectivity via diffusion weighted imaging was examined in sixty-four children, ages 5-17 years, with reading disability, ASD, or typical development (TD), who were matched in age, gender, intelligence, and diffusion data quality. RESULTS: Children with reading disability and children with ASD exhibited reduced PWM compared to children with TD. The two diagnostic groups showed altered white-matter microstructure in the temporo-parietal portion of the left arcuate fasciculus (AF) and in the temporo-occipital portion of the right inferior longitudinal fasciculus (ILF), as indexed by reduced fractional anisotropy and increased radial diffusivity. Moreover, the structural integrity of the right ILF was positively correlated with PWM ability in the two diagnostic groups, but not in the TD group. CONCLUSIONS: These findings suggest that impaired PWM is transdiagnostically associated with shared neuroanatomical abnormalities in ASD and reading disability. Microstructural characteristics in left AF and right ILF may play important roles in the development of PWM. The right ILF may support a compensatory mechanism for children with impaired PWM.

Development of verbal passive in Williams syndrome.

PURPOSE: To experimentally investigate knowledge of passives of actional (hold) and psychological (love) verbs in children with Williams syndrome (WS). Passives are usually reported to be in line with mental age in WS. However, studies usually focus on passives of actional verbs only. METHOD: Twenty-six children with WS, ages 6-16, and 3 groups of typically developing controls, ages 3;6-14;4 (years;months), individually matched to the WS group on nonverbal reasoning, receptive vocabulary, or grammar, participated. Their comprehension of actives and short and long passives (with and without the by-phrase) was tested using a sentence-picture-matching task. RESULTS: Children with WS performed well above chance on passives of actional verbs but extremely poorly on passives of psychological verbs (short and long). Furthermore, their performance on both types of passives was worse than that of matched controls. CONCLUSIONS: The results reveal a previously unreported deficiency in the domain of syntax in WS, suggesting a particular difficulty with the structure of the verbal passive, not directly related to general levels of nonverbal abilities, receptive vocabulary, or general comprehension of grammar. It is argued that the difficulty in the formation of verbal passives in WS stems from a deficit in forming argument chains.