The Role of the Vagus Nerve in the Sleep States of Premature Infants
Undergraduate: Stephanie Okonmah-Obazee
Faculty Advisor: Greg Lewis
Department: Psychology & Neuroscience
The polyvagal theory explains how neural regulation of the heart through the vagus nerve can influence a child¿¿¿s psychological state and social interactions through either dysregulation or regulation of the heart by brain systems. Children who have dysregulation are at a higher risk of anxiety, depression, aggression, and other social problems. Premature birth is a risk factor for dysregulation, as completion of the myelination process for the vagus has not been achieved. ECG data from premature infants was obtained from the NICU at Columbia University. ECG data was processed through a combination of automated and visualized procedures to identify the peak of the R-waves. From there the interbeat intervals (IBIs) were extracted between each R-wave to reveal the respiratory sinus arrhythmia (RSA) of the infant. It was found that there was a positive correlation between mean IBI and RSA. The influence of sleep state (active and quiet sleep) on the coupling of RSA and mean IBIs was explored in the premature newborns. Sleep serves as a bidirectional interaction between the brain and the body. The physiological differences that occur between the two sleep states reveal the individual differences in the efficiency of the autonomic nervous system (ANS). It was found that regulation of the vagus nerve changes as a function of sleep state, revealing a difference in the function of the ANS and a measure of the functionality of the brain-vagus-heart regulatory system.