Alexithymia and the split brain. V. EEG alpha-band interhemispheric coherence analysis.

摘要: Electroencephalographic (EEG) recordings were obtained while 6 completely commissurotomized patients, 2 partially and 8 precision-matched normal control subjects watched 4 times a film symbolically depicting death. Our hypothesis was that alexithymia--a diminished capability to verbally express moods, symbols, feelings--would be greater for patients because loss of cerebral commissures reduces interhemispheric communication, separating right-hemisphere-dependent affective understanding left-hemisphere-dependent verbalization. Path covariance structure analyses confirmed callosotomy decreased alpha-band EEG coherences (after adjustment mean intrahemispheric coherence) between pairs scalp electrode channels placed homologously over frontal, parietal, temporal lobes the brain. This result occurred both an index coherence latent variable indicated by 3 adjusted coherences. Reduced levels in turn increased alexithymia, overall lexical-level content-analytic measures verbal responses filmic stimulus.