2 mediums (1 Electroencephalography (2008) (39) spiritist presenting (EEG) psychography
and 1 Data colleted in from Camdomble Assessment of heart 1999 presenting rate, muscle tone psychophony) and 1 and skin conductance control (no mediumship, same sociocultural environment) Hageman et al.
All reported that during the study, they were able to reach their usual trance-like state during the psychography task and were in their regular state of consciousness during the control task.
The researchers found that the experienced psychographers showed lower levels of activity in the left hippocampus (limbic system), right superior temporal gyrus, and the frontal lobe regions of the left anterior cingulate and right precentral gyrus during psychography compared to their normal (non-trance) writing.
The frontal lobe areas are associated with reasoning, planning, generating language, movement, and problem solving, perhaps reflecting an absence of focus, self-awareness and consciousness during psychography, the researchers hypothesize.
From this vast and necessary [chronological] material of biography, psychography selects only that which is indispensable for its particular purpose.
Bradford understood the dangers, and addressed them: "It must be admitted that psychography is always in danger of degenerating into gossip.