Use of the oculocardiac reflex to assess vagal reactivity during quiet sleep in neonates.

Arousal from sleep can be a protective response to life-threatening stimuli. Hence, faults within state-switching processes may lead to fatal events. To investigate the role of the nervous system during cardiac failure triggered by phasic, vagally mediated stimulation, we analysed autonomic and behavioural reactions in 50 premature neonates during quiet sleep (QS) -- a sleep state characterized by a preponderance of tonic, parasympathetic activity.