RESUMO
The study investigated autonomic regulation during feeding in six-month old infants with a history of excessive crying (EC) and social-behavioral development at 12 and 24 months. When contrasted with non-EC infants (NEC), EC infants had atypical autonomic responses observed as dampened reductions in respiratory sinus arrhythmia (RSA) and decreases in heart period (HP) during feeding. EC infants demonstrated atypical autonomic regulation only if they were bottle-fed, while breastfed EC infants had patterns of autonomic regulation similar to NEC infants. Behavioral data suggest that while a history of EC was related to social-emotional behaviors at 12 and 24 months, breastfeeding may buffer the behavioral effects of EC on sociability at 24 months.
Assuntos
Aleitamento Materno , Arritmia Sinusal Respiratória , Sistema Nervoso Autônomo/fisiologia , Choro/fisiologia , Emoções , Feminino , Humanos , Lactente , Arritmia Sinusal Respiratória/fisiologiaRESUMO
Autonomic reactivity was studied in individuals with fragile X syndrome (FXS), a genetic disorder partially characterized by abnormal social behavior. Relative to age-matched controls, the FXS group had faster baseline heart rate and lower amplitude respiratory sinus arrhythmia (RSA). In contrast to the typically developing controls, there was a decrease in RSA with age within the FXS group. Moreover, within the FXS group heart rate did not slow with age. The FXS group also responded with an atypical increase in RSA to the social challenge, while the control group reduced RSA. In a subset of the FXS group, the autonomic profile did not change following 2 months and 1 year of lithium treatment. The observed indices of atypical autonomic regulation, consistent with the Polyvagal Theory, may contribute to the deficits in social behavior and social communication observed in FXS.
