Neonatal responsivity to gustatory stimulation: The gustatory-vagal hypothesis
Sucking frequency, heart rate, and cardiac vagal tone (V) were monitored in neonates during manipulations of sweet gustatory stimulation. In response to increased sweetness, reductions in cardiac vagal tone and increases in heart rate paralleled increased sucking frequency. Individual differences in cardiac vagal tone were correlated with the magnitude of heart rate changes to gustatory stimulation.
Porges, S., & Lipsitt, LP. (1993). Neonatal responsivity to gustatory stimulation: The gustatory-vagal hypothesis. Infant Behavior & Development, 16(4), 487-494. https://doi.org/10.1016/0163-6383(93)80006-T