Biological Underpinnings of Socio-emotional Regulation in Preterm Infants and Healthy Controls: Insights From EEG and Epigenetic Data

Preterm infants (PT) often need to spend their first weeks of life in the Neonatal Intensive Care Unit (NICU) where they are exposed to several adverse conditions. Whereas a consistent number of studies suggest that NICU-related experiences may have effects on infant development including long-term impairments in emotional regulation, the underlying mechanisms remain partially unexplored. Spectral analysis of EEG signal has demonstrated that frontal alpha-band asymmetry represents a reliable biomarker of social-emotional functioning. In the literature, higher right frontal activation has been associated with worse emotional regulation but no study has measured this value during a condition of social-emotional stress such as the Still Face paradigm. Our hypothesis is that higher alpha activity will be recorded in right frontal areas in premature infants compared to healthy controls and that this activation will be associated with higher negative emotionality (i.e., worse socio-emotional regulation) expressed during the Still Face paradigm. Moreover, despite several changes in epigenetic patterns have already been reported in association with prematurity and early adverse experiences, the relationship between epigenetic changes and electroencephalographic patterns (i.e. frontal alpha asymmetry) remains unexplored. The investigators therefore expect to find associations between increased methylation levels of socio-emotional and stress related genes (i.e. SLC6A4, NR3C1, OXTR, Piezo1, Piezo2, TRPV1 and TRPM8) with spontaneous oscillations of neural activity at frontal sites measured by EEG (i.e. frontal alpha asymmetry). Finally, there is ample evidence that infant's socio-emotional regulation abilities are highly dependent on the behaviors of their caregivers. More recent studies have shown that behavior can be influenced by interoceptive awareness, i.e., the ability to perceive the physiological condition of one's body in this way and to represent one's internal states. Better interoceptive awareness is associated with better recognition of others' needs, more empathetic behaviors, and better emotional regulation. Therefore, with the present exploratory study, the investigators will compare the interceptive awareness of mothers of preterm infants with that of mothers of full-term infants by exploring possible associations of this dimension with the socio-emotional responses of preterm infants and healthy controls. The investigators expect that better socio-emotional regulation of infants is predicted by a higher level of interoceptive awareness in mothers, regardless of prematurity condition.