Electroencephalographic Evidence of Correlated Event-Related Signals Between the Brains of Spatially and Sensory Isolated Human Subjects

Abstract

Objective:

To determine whether correlated event-related potentials (ERPs) can be detected between the brains of spatially and sensory isolated human subjects.

Design and setting:

Simultaneous digitized electroencephalograms (EEGs) were recorded from the occipital area in pairs of human subjects placed in sound attenuated rooms separated by 10 meters. One person relaxed in one of the rooms while the other received visual stimulation while in the other room. Prior to each experiment, members of the pair were randomly designated as sender and receiver. Sessions were subsequently repeated with subjects reversing their roles. Previous to each session, the sender was instructed "to attempt sending an image/thought." The receiver was instructed "to remain open to receive any image/thought from his/her partner." Alternating stimulus-on/stimulus-off conditions were presented throughout the session to the sender, while a stimulus-off condition was presented to the receiver.

Subjects:

Thirty-seven (37) female, and 23 male subjects (n = 60; 30 pairs) participated in the study. Subjects knew each other well and claimed to have previous experience of being emotionally/psychologically connected to one another.

Outcome measures:

A Runs test was applied to compare EEG "hits" in the receiver's EEG during the sender' stimulus-on condition versus sender's stimulus-off conditions. Test results at p < 0.01 were considered evidence of correlated brain signals. Pairs in whom at least one member had significant results were invited back for replication.

Results:

Of the 60 subjects tested, 5 (4 women/1 man) showed significantly higher brain activation (p < 0.01) during their sending partner's stimulus-on condition as compared to stimulus-off condition. Using the Stouffer z meta-analytic method all receiver EEG results across all 60 subjects were combined by transforming the individual session p values into z scores. Data analyses showed overall significant results for EEG data recorded during the flickering condition (z =-3.28, p = 0.0005) as well as nonsignificant results for data recorded during the static condition (z= 0.35, p = 0.64). Four pairs participated in a replication experiment during which one pair replicated the effect.

Conclusions:

These results indicate that in some pairs of human subjects a signal may be detected in the brain of a distant member of the pair when the brain of the other member is visually stimulated. These data support the findings of similar studies performed in seven laboratories reported in the peer-reviewed literature since 1963. Research in this area should now proceed with investigation of its physical and biologic mechanism, its generalizability to varying populations and relationships, and its clinical application.