A second look at second-order belief attribution in autism

Compared the performance of autistic and mentally retarded subjects, all of whom had passed a standard first-order test of false belief, on a new second-order belief task 12 autistic and 12 mentally retarded subjects, matched on verbal mental age (assessed by PPVT and a sentence comprehension subtest of the CELF) and full-scale IQ were given two trials of a second-order reasoning task which was significantly shorter and less complex than the standard task used in all previous research. The majority of subjects in both groups passed the new task, and were able to give appropriate justifications to their responses. No group differences were found in performance on the control or test questions. Findings are interpreted as evidence for the role of information processing factors rather than conceptual factors in performance on higher order theory of mind tasks.This study was supported by a grant from the National Institute of Deafness and Other Communication Disorders (1RO1 DC 01234). We thank Jason Barker for his extensive help with this study. We are also very grateful to the schools where the study was conducted including the League School, and the public school systems in the following towns in Massachusetts: Hanover, Hanson, Hingham, Milton, Plymouth, and Rockland. We offer special thanks to Alan Dewey, Mary Dollar, Sandy D'Giacomo, Herman Fishbein, William Griffin, Nancy Kearns, Judy Monahan, Debbie Newhall, Cay Riley, Robert Sherman, and Kathy Staska for their continued support of our research.     

Changing the perspective on early development of Rett syndrome

We delineated the achievement of early speech-language milestones in 15 young children with Rett syndrome (MECP2 positive) in the first two years of life using retrospective video analysis. By contrast to the commonly accepted concept that these children are normal in the pre-regression period, we found markedly atypical development of speech-language capacities, suggesting a paradigm shift in the pathogenesis of Rett syndrome and a possible approach to its early detection.     

Early socio-communicative forms and functions in typical Rett syndrome

Rett syndrome (RTT) is a severe neurological disorder characterized by a developmental regression in motor and speech-language domains. There is, however, limited research on socio-communicative development of affected children before the onset of regression. We analyzed audio–video recordings made by parents of six 9- to 12-month old girls later diagnosed with typical RTT, applying the Inventory of Potential Communicative Acts (IPCA) to identify early communicative forms and functions. Each girl used at least one communicative form (e.g., body movement, eye gaze, or vocalizations) to gain attention and answer, but none were observed to make choices or request information. Varying numbers of children were observed to perform other communicative functions according to the IPCA including social convention, rejecting or requesting an object. Non-verbal forms (e.g., reaching, moving closer, eye contact, smiling) were more common than non-linguistic verbal forms (e.g., unspecified vocalizations, pleasure vocalizations, crying). (Pre-)linguistic verbal forms (e.g., canonical or variegated babbling, proto-words) were not used for communicative purposes. These data suggest that atypical developmental patterns in the socio-communicative domain are evident prior to regression in young individuals later diagnosed with RTT.     

Brief Report: Parents’ Declarative Use of Deictic Gestures Predict Vocabulary Development in Infants at High and Low Risk for Autism Spectrum Disorder

Journal of Autism and Developmental Disorders - We examined the communicative intentions behind parents’ deictic gesture use with high-risk infants later diagnosed with autism spectrum...     

Structural asymmetries of language-related gray and white matter and their relationship to language function in young children with ASD

Children with autism spectrum disorder (ASD) are highly variable in their language abilities, but the neural bases of these individual differences are poorly understood. Structural magnetic resonance imaging (MRI) and magnetic resonance diffusion tensor imaging (DTI) tractography were used to examine asymmetries in language-related gray- and white-matter and their relationships to language ability in a sample of 20 children with ASD, aged 4–7 years, and a reference sample of 20 typically developing (TD) children, aged 6–11 years. Children with ASD did not differ significantly from TD children in gray matter asymmetries, but were significantly less left-lateralized than TD children in the volume and radial diffusivity (RD) of the arcuate fasciculus (AF). They did not differ in the fractional anisotropy (FA) or the mean or axial diffusivity of the AF. Within the ASD group, exploratory analyses revealed that decreased leftward/increased rightward asymmetry of pars opercularis was associated with higher language ability and bilaterally increased FA and decreased RD of the AF. In conclusion, children with ASD exhibited atypical asymmetry in language-related white-matter structure as well as an atypical pattern of brain-language relationships that suggest that they may meet language milestones and acquire normal language via a different neurodevelopmental trajectory from TD children.     

Language-association cortex asymmetry in autism and specific language impairment

Language deficits are among the core impairments of autism. We previously reported asymmetry reversal of frontal language cortex in boys with autism. Specific language impairment (SLI) and autism share similar language deficits and may share genetic links. This study evaluated asymmetry of frontal language cortex in a new, independent sample of right-handed boys, including a new sample of boys with autism and a group of boys with SLI. The boys with autism were divided into those with language impairment (ALI) and those with normal language ability (ALN). Subjects (right-handed, aged 6.2-13.4 years) included 22 boys with autism (16 ALI and 6 ALN), 9 boys with a history of or present SLI, and 11 normal controls. MRI brain scans were segmented into grey and white matter; then the cerebral cortex was parcellated into 48 gyral-based divisions per hemisphere. Group differences in volumetric asymmetry were predicted a priori in language-related regions in inferior lateral frontal (Broca's area) and posterior superior temporal cortex. Language impaired boys with autism and SLI both had significant reversal of asymmetry in frontal language-related cortex; larger on the right side in both groups of language impaired boys and larger on the left in both unimpaired language groups, strengthening a phenotypic link between ALI and SLI. Thus, we replicated the observation of reversed asymmetry in frontal language cortex reported previously in an independent autism sample, and observed similar reversal in boys with SLI, further strengthening a phenotypic link between SLI and a subgroup of autism. Linguistically unimpaired boys with autism had similar asymmetry compared with the control group, suggesting that Broca's area asymmetry reversal is related more to language impairment than specifically to autism diagnosis.     

Abnormal activation of the social brain during face perception in autism

ASD involves a fundamental impairment in processing social-communicative information from faces. Several recent studies have challenged earlier findings that individuals with autism spectrum disorder (ASD) have no activation of the fusiform gyrus (fusiform face area, FFA) when viewing faces. In this study, we examined activation to faces in the broader network of face-processing modules that comprise what is known as the social brain. Using 3T functional resonance imaging, we measured BOLD signal changes in 10 ASD subjects and 7 healthy controls passively viewing nonemotional faces. We replicated our original findings of significant activation of face identity-processing areas (FFA and inferior occipital gyrus, IOG) in ASD. However, in addition, we identified hypoactivation in a more widely distributed network of brain areas involved in face processing [including the right amygdala, inferior frontal cortex (IFC), superior temporal sulcus (STS), and face-related somatosensory and premotor cortex]. In ASD, we found functional correlations between a subgroup of areas in the social brain that belong to the mirror neuron system (IFC, STS) and other face-processing areas. The severity of the social symptoms measured by the Autism Diagnostic Observation Schedule was correlated with the right IFC cortical thickness and with functional activation in that area. When viewing faces, adults with ASD show atypical patterns of activation in regions forming the broader face-processing network and social brain, outside the core FFA and IOG regions. These patterns suggest that areas belonging to the mirror neuron system are involved in the face-processing disturbances in ASD.     

Extreme sensory modulation behaviors in toddlers with autism spectrum disorders.

This study examined the incidence of extreme sensory modulation behaviors in toddlers with autism spectrum disorders (ASD) and investigated the consistency of sensory information across measures. Parent report of sensory behaviors in 101 toddlers with ASD was compared with 100 toddlers who were typically developing matched on chronological age and 99 additional infants or toddlers matched on mental age. Measures included the Infant/Toddler Sensory Profile, Infant-Toddler Social Emotional Assessment, Autism Diagnostic Interview-Revised, and Autism Diagnostic Observation Schedule-Generic. Toddlers with ASD were most distinct from typically developing groups in their high frequency of underresponsiveness and avoiding behaviors and their low frequency of seeking. Within the toddlers with ASD, there were significant associations across sensory parent report measures, but parent report was not correlated with clinical observation. Findings point to the early onset of an extreme sensory profile in ASD. Occupational therapists need to assess multiple domains of sensory behaviors to accurately identify the needs of toddlers with ASD.