Fig. 5.

Description of maturational and mechanistic differences during both sleep and awake state. Note that the mechanistic differences in awake vs. sleep state regarding UES contractile reflex recruitment during time 1 are maintained during time 2. Additionally, there are increased recruitment frequencies of UES contractile reflex, LES relaxation reflex, and both esophago-deglutition responses and secondary peristalsis (SP) peristaltic reflexes during sleep across maturation. PMA, postmenstrual age.