Brain and heart interaction during sleep in the healthy and sleep apnoea

Neurocardiology is a study of interaction between the brain and the heart. This paper presents the pilot study which assessed the multivariate analysis of EEG and ECG activity in the healthy and sleep apnoea patients during different sleep stages. Three synchronization measures based on a linear method (cross-correlation), information theory (mutual information) and nonlinear interdependence, were applied to analyse the EEG and ECG signals. The results indicated that the brain is dependent more on the heart electrical activity during different sleep stages and brain hemispheres in the healthy and sleeps apnoea. This might suggest that the information that flows from the heart, actually modulates the brain electrical activity or simply that heart drives the brain activity.