Spontaneous conscious covert cognition states and brain electric spectral states in canonical correlations

Correlations between subjective, conscious, spontaneous cognitions and EEG power spectral profiles were investigated in 20 normal volunteers (2 sessions each) during relaxation-drowsiness-sleep onset. Four-channel EEG (temporal-parietal and parietal-central, left and right) was continuously recorded. The subjects were prompted 15 times per session to give brief reports of their ongoing thoughts. The reports were rated on 23 scales, and the 16 seconds of EEG recording preceding the prompts were spectral analyzed. Canonical correlation analysis was applied to the data (23 cognition ratings and 124 EEG spectral values for each of the 538 prompts). Four of the 23 pairs of canonical EEG variables and cognition variables were significant (p < 0.016) with correlation coefficients ranging from 0.78 to 0.62. The four pairs of canonical variables showed distinctive features in EEG spectra and cognition styles. The results demonstrate ruleful correspondences between EEG states and spontaneous, conscious, covert, cognitive-emotional states in a no-input, no-task, no-response paradigm.