[Is there a correlation between the phases of CNV and the power spectrum of the EEG?]

In 14 volunteers, the relationships between CNV and EEG power spectrum were studied during 3 periods of 1 sec: before S1, between S1 and S2, and after S2. We noted first a relation between CNV amplitude and EEG spectrum over the 3 periods: there was an inverse correlation for the alpha band, and a direct correlation for the beta band. We also observed a direct, strong correlation (r = 0.94) between CNV slope and alpha band reactivity during the S1-S2 interval, but this held only for subjects showing a decrease of alpha activity during the S1-S2 interval. There was no correlation at all between the positive phase (post-S2) of the CNV and EEG. These results are discussed in terms of functional states of the brain influencing CNV development, as well of the various modes of activation and reactivity at the individual level that modify the relationships between CNV and EEG.