A series of experiments has shown increased brainwave synchrony between the two hemispheres when pairs of subjects are attempting to "feel each other's presence." Experimenters also recorded an increasing similarity of EEG pattern between the pairs of communicators over the course of the session. In some instances, the match between subjects during this "empathic communication" was dramatic. (See chart. page 8. [not included]). Resemblance between the EEG's of partners was found even when they had not met or tried to communicate before the experiment. Judges were shown all possible combinations of the EEG patterns of individuals recorded during communication. Seventy per cent of the time they were able to identify those produced by partners.
Thirteen pairs were studied and four groups of three persons each. The three-person group showed a weaker effect than the pairs. Normally the left and right hemispheres are somewhat independent in their electrical activity. Synchronous activity has been associated with unusual states of focus, meditation or efforts at healing.
"The subject with the highest concordance was the one who most influenced the sessions," said Jacobo Grinberg-Zylerbaum and Julieta Ramos of the Universidad Nacional Autonoma de Mexico. In other words, the EEG of the individual with less synchronicity between hemispheres would gradually come to resemble the EEG of the person whose two sides more closely resembled each other.
Sessions took place in a soundproof and darkened Faraday cage (a lead-screened chamber that filter out all outside electromagnetic activity). Each pair was instructed to close their eyes and to try to "communicate by being aware of the other's presence and to signal [the experimenter] when you feel this has occurred." EEG analysis showed that during the periods when subjects reported communicating "the interhemispheric correlation patterns of each subject are very alike." One subject's EEG became similar to each of three partners with whom he was paired. After one session, when the partners reported a feeling of having blended, their EEG patterns had become nearly identical.
There was no talking or touching during the sessions. Some subjects reported feeling physical sensations, and others said they had active images and thoughts of their partners. During control sessions, when subjects sat in isolation before and after each pair session, subjects showed no increased synchrony between their own hemispheres or between each other.
The researchers said that they have been studying the phenomena for several years, but only recently had access to sophisticated equipment for verification purposes. The findings confirm Grinberg-Zylerbaum's theory, proposed in a 1981 book, that "neuronal fields" can interact and alter each other.
Their report appeared in the //International Journal of Neuroscience 36:41-52, Facultad de Psicologia, Universidad Nacional Autonoma de Mexico, Mexico City 04510 D.F.