Despite evidence for the association of some pre-, peri- and neonatal risk factors associated with PDD, it remains unclear whether these risks are causal or play a secondary role in shaping clinical expression in individuals with genetic vulnerability. A plausible hypothsesis is that improvements in obstetric and neonatal management have led to an increased rate of survivors with pre-existing brain damage. Given the variety of risk factors, we propose that future studies should investigate combinations of multiple factors, rather than focusing on a single factor.

Impaired language is a prominent behavioral marker of autism spectrum disorders (ASD), but its neurobiological underpinnings are incompletely understood. We studied letter and category fluency in 14 high functioning ASD individuals and 14 age-matched controls. Each fluency condition was compared to self-paced repetition of the word "nothing." Responses were recorded to monitor performance. In letter fluency, the ASD group had significantly greater activation than controls in the right frontal and right superior temporal lobe. Between-group differences were not observed in left prefrontal cortex. By examining functional asymmetry in frontal cortex, we found that the ASD group had significantly reduced lateralization of activation patterns in letter fluency compared to the controls. In category fluency, no between-group differences in lateralization were found, in light of greater bilateral activation in controls. These findings indicate reduced hemispheric differentiation for certain verbal fluency tasks in ASD, consistent with some previous evidence of atypical functional and structural asymmetries in autism. Abnormal functional organization may contribute to the language impairment seen in ASD.

No abstract

The academic and behavioral progress of children is associated with the timely development of reading and writing skills. Dysgraphia, characterized as a handwriting learning disability, is usually associated with dyslexia, developmental coordination disorder (dyspraxia), or attention deficit disorder, which are all neuro-developmental disorders. Dysgraphia can seriously impair children in their everyday life and require therapeutic care. Early detection of handwriting difficulties is, therefore, of great importance in pediatrics. Since the beginning of the 20th century, numerous handwriting scales have been developed to assess the quality of handwriting. However, these tests usually involve an expert investigating visually sentences written by a subject on paper, and, therefore, they are subjective, expensive, and scale poorly. Moreover, they ignore potentially important characteristics of motor control such as writing dynamics, pen pressure, or pen tilt. However, with the increasing availability of digital tablets, features to measure these ignored characteristics are now potentially available at scale and very low cost. In this work, we developed a diagnostic tool requiring only a commodity tablet. To this end, we modeled data of 298 children, including 56 with dysgraphia. Children performed the BHK test on a digital tablet covered with a sheet of paper. We extracted 53 handwriting features describing various aspects of handwriting, and used the Random Forest classifier to diagnose dysgraphia. Our method achieved 96.6% sensibility and 99.2% specificity. Given the intra-rater and inter-rater levels of agreement in the BHK test, our technique has comparable accuracy for experts and can be deployed directly as a diagnostics tool.

No abstract

Background: To date, few studies have focused on the viewpoints of autistic persons themselves despite an increasing number of published autobiographies. The aim of this study is to highlight their personal experiences, and to compare them to scientific and medical knowledge and representations. Method: Adopting an anthropological approach, we analyzed 16 autobiographical writings and 5 interviews with autistic persons. We systematically screened this material and explored the writers’ sociodemographic characteristics, cognitive skills and interests with a focus on their sensory-perceptual experiences and their representations of autism. Results: The authors’ ages (22–67 years), their countries (n = 8) and backgrounds were varied, and most of them were high-functioning individuals with autism or Asperger syndrome. The most striking observations were that all of them pointed out that unusual perceptions and information processing, as well as impairments in emotional regulation, were the core symptoms of autism, whereas the current classifications do not mention them. Conclusions: Our results suggest that what has been selected as major signs by psychiatric nosography is regarded as manifestations induced by perceptive peculiarities and strong emotional reactions by the autistic persons who expressed themselves. These considerations deserve to be taken into account by professionals to better understand the behavior and needs of autistic persons. We propose to include this point in the reflection on the next psychiatric classifications.

Abnormalities in melatonin physiology may be involved or closely linked to the pathophysiology and behavioral expression of autistic disorder, given its role in neurodevelopment and reports of sleep-wake rhythm disturbances, decreased nocturnal melatonin production, and beneficial therapeutic effects of melatonin in individuals with autism. In addition, melatonin, as a pineal gland hormone produced from serotonin, is of special interest in autistic disorder given reported alterations in central and peripheral serotonin neurobiology. More specifically, the role of melatonin in the ontogenetic establishment of circadian rhythms and the synchronization of peripheral oscillators opens interesting perspectives to ascertain better the mechanisms underlying the significant relationship found between lower nocturnal melatonin excretion and increased severity of autistic social communication impairments, especially for verbal communication and social imitative play. In this article, first we review the studies on melatonin levels and the treatment studies of melatonin in autistic disorder. Then, we discuss the relationships between melatonin and autistic behavioral impairments with regard to social communication (verbal and non-verbal communication, social interaction), and repetitive behaviors or interests with difficulties adapting to change. In conclusion, we emphasize that randomized clinical trials in autism spectrum disorders are warranted to establish potential therapeutic efficacy of melatonin for social communication impairments and stereotyped behaviors or interests.

There is a growing interest in the role of biological and behavioral rhythms in typical and atypical development. Recent studies in cognitive and developmental psychology have highlighted the importance of rhythmicity and synchrony of motor, emotional, and interpersonal rhythms in early development of social communication. The synchronization of rhythms allows tuning and adaptation to the external environment. The role of melatonin in the ontogenetic establishment of circadian rhythms and the synchronization of the circadian clocks network suggests that this hormone might be also involved in the synchrony of motor, emotional, and interpersonal rhythms. Autism provides a challenging model of physiological and behavioral rhythm disturbances and their possible effects on the development of social communication impairments and repetitive behaviors and interests. This article situates autism as a disorder of biological and behavioral rhythms and reviews the recent literature on the role of rhythmicity and synchrony of rhythms in child development. Finally, the hypothesis is developed that an integrated approach focusing on biological, motor, emotional, and interpersonal rhythms may open interesting therapeutic perspectives for children with autism. More specifically, promising avenues are discussed for potential therapeutic benefits in autism spectrum disorder of melatonin combined with developmental behavioral interventions that emphasize synchrony, such as the Early Start Denver Model.