Investigating the effect of cognitive stress on cardiorespiratory synchronization

Synchrograms have been used to investigate the effects of cognitive stress, induced by the Stroop test, on the phase synchronization of the cardiac and respiratory systems. The cardiorespiratory interactions have been investigated during a rest and cognitive stressful task, namely the Stroop test, and found that cardiorespiratory synchronization decreased during cognitive stress. Synchrogram techniques and the Hilbert transform have been used to analyse phase syncronization. Our results support the hypothesis that respiration is key for improving the feedback between the cardiac and respiratory systems.