Cortico-Cerebellar neurodynamics during social interaction in Autism Spectrum Disorders.

BACKGROUND: Exploring neural network dynamics during social interaction could help to identify biomarkers of Autism Spectrum Disorders (ASD). A cerebellar involvement in autism has long been suspected and recent methodological advances now enable studying cerebellar functioning in a naturalistic setting. Here, we investigated the electrophysiological activity of the cerebro-cerebellar network during real-time social interaction in ASD. We focused our analysis on theta oscillations (3-8 Hz), which have been associated with large-scale coordination of distant brain areas and might contribute to interoception, motor control, and social event anticipation, all skills known to be altered in ASD. METHODS: We combined the Human Dynamic Clamp, a paradigm for studying realistic social interactions using a virtual avatar, with high-density electroencephalography (HD-EEG). Using source reconstruction, we investigated power in the cortex and the cerebellum, along with coherence between the cerebellum and three cerebral-cortical areas, and compared our findings in a sample of participants with ASD (n = 107) and with typical development (TD) (n = 33). We developed an open-source pipeline to analyse neural dynamics at the source level from HD-EEG data. RESULTS: Individuals with ASD showed a significant increase in theta band power over the cerebellum and the frontal and temporal cortices during social interaction compared to resting state, along with significant coherence increases between the cerebellum and the sensorimotor, frontal and parietal cortices. However, a phase-based connectivity measure did not support a strict activity increase in the cortico-cerebellar functional network. We did not find any significant differences between the ASD and the TD group. CONCLUSIONS: This exploratory study uncovered increases in the theta band activity of participants with ASD during social interaction, pointing at the presence of neural interactions between the cerebellum and cerebral networks associated with social cognition. It also emphasizes the need for complementary functional connectivity measures to capture network-level alterations. Future work will focus on optimizing artifact correction to include more participants with TD and increase the statistical power of group-level contrasts.

Characteristics associated with feeding organic foods during complementary feeding: the nationwide Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort.

Organic food consumption and its effects on health remain understudied in adults and in children. The aim of this study was to describe family characteristics associated with feeding infants organic foods during the complementary feeding period. The analysis included 9764 children from the French Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort. In addition to telephone interviews conducted at 2, 12 and 24 months, a monthly questionnaire about milk feeding and complementary foods (including organic foods) was completed by parents between 3 and 10 months. Associations between family characteristics and feeding with organic foods during complementary feeding were analysed by multivariable multinomial logistic regression. Overall, 51 % of infants never consumed organic food during the complementary feeding period (up to 10 months), 24 % sometimes, 15 % often and 9 % always or almost always. As compared with infants never fed organic foods, those 'often' or 'always' fed organic foods were born to older mothers, with higher education level or family income, and lower pre-pregnancy BMI. As compared with never-smoking women, women who had stopped smoking before pregnancy were more likely to feed their infant organic foods. Feeding with organic foods was also related to long breast-feeding duration and later introduction to complementary foods. To conclude, associations between feeding with organic foods and family socio-economic position as well as infant feeding practices need to be considered when studying the impact of organic foods on children's health and development.