Variations in EEG coherence as an index of the affective content of dreamsfrom REM sleep: Relationships with face imagery

EEG coherence was examined in relation to four measures of socioemotional d ream content, including a new measure-the proportional representation of a character's face. Twenty-four healthy subjects, recorded for sleep stages a nd EEG activity, were awakened from REM sleep to report dream mentation and to rate it on these variables. Coherence scores were calculated for homolo gous interhemispheric electrode pairs (Fp1-Fp2, F3-F4, F7-F8, C3-C4, P3-P4, O1-O2, T3-T4, T5-T6) and for left and right intrahemispheric pairs for del ta, theta, alpha, betal, and beta2 frequencies. These were correlated with the mentation measures. Positive correlations were found between average in terhemispheric coherence in most bands and the character face measure. A br eakdown by gender revealed that this relation ship was most evident for wom en, whereas for men positive correlations were observed between coherence a nd negative self-feeling. That similar relationships also obtained for both left and right intrahemispheric coherence is consistent with the hypothesi s that dreamed socioemotional interactions reflect the integrative function ing of many brain regions in both hemispheres. (C) 1999 Academic Press.