Frontal electroencephalographic (EEG) activity and mediumship: a comparative study between spiritist mediums and controls

Abstract

Mediumship and spirit possession are cultural phenomena found worldwide. The Spiritism, popular in Brazil, is a religious tradition that emphasizes mediumship. The "absorption hypothesis" (the association of marked increases in focused attention with concomitant decreases in self-awareness) is one of the neuropsychological explanatory theories for these experiences. We measured electroencephalographic (EEG) spectral power in frontal electrodes within theta, alpha and beta bandwidths, as well as cross-regional cortical coherences, in female Spiritist experienced mediums (n = 10) and in female non-medium control subjects from the same religious context (n = 10). Scalp EEG signals were captured simultaneously from participants in each of the two groups in three different moments: before, during and immediately after mediumistically speaking. Compared to non-medium controls, the mediums had greater beta power on some electrodes in all phases of the experiment, greater theta power on one electrode at the communication phase and greater alpha power on one electrode at the post-communication phase. No condition effects (within-group comparisons) were detected in any group. No group effects were noted for cross regional cortical coherences. No ictal EEG pattern was observed, except for one participant in the mediums group. These findings support the hypothesis that absorption could have a mechanistic role in anomalous sensorial experiences such as mediumship. The coherence pattern in mediums during the anomalous experience differed from prior studies on pathological dissociation and on hypnotic states. Cognitive control processes seem to be engaged during the anomalous sensorial experiences.Bastos Jr. MAV et al. / Arch Clin Psychiatry. 2016;43(2):20-6

A physiological examination of perceived incorporation during trance

“…The mean age at which participants had their first channeling experience was older than other types of anomalous information reception experiences 6 and other self-reported trance channels where such data were reported 10, 25, 36 although the standard deviation and range of the starting age was large. Participants reported a medium level of trance (4.7 out of 10) during channeling which was not as deep one might imagine because of ethnographic reports of deep trances during possession rituals 77 .…”

“…Although trance states are currently considered a symptom of dissociation 16, 20, 22 , trance mediums do not show higher rates of pathological dissociation than the general population 23, 24 . Most researchers would define mediums as people who communicate with discarnate or deceased personalities on a regular basis 25 while trance mediums do so while under trance. Roxburgh and Roe surveyed 233 mediums and spiritualists in the United Kingdom and found no significant difference between mediums and non-medium spiritualists on the Dissociative Experience Scale.…”

“…A recent systematic review evaluated trance channels during sessions and found an increase in noradrenaline levels, muscle tone, heart rate, and in spectral power in alpha, beta, and theta EEG frequency bands 26 . Another study examined EEG before, during, and after channeling in 10 experienced full-trance channels and 10 non-channeler controls, all recruited from the same Spiritist cultural community 25 . The study found that channels compared to the controls had greater beta EEG power in all phases of the experiment, greater theta power on one electrode out of 22 while communicating, and greater alpha power on one electrode during the post-communication phase.…”

Neural correlates of the shamanic state of consciousness

“…Further, previous investigations of brain activity during meditation have revealed increased gamma activity (23)(24)(25)(26)(27)(28), with some attributing elevations in gamma to enhanced perceptual clarity (26), spontaneous visual imagery (29), or increased attentional effort (24). However, other trance states, such as possession trance, are frequently characterized by power changes in the theta, alpha, or beta bands (30)(31)(32), without analysis of the gamma band. Thus, while changes in the other frequency bands are absent during shamanic trance, it remains unknown whether our findings of increased gamma power are comparable.…”

Antropologia Médica Vitalista: uma ampliação ao entendimento do processo de adoecimento humano

“…Respondendo a essa demanda, pesquisas e publicações relacionadas à interconexão entre Saúde, Espiritualidade e Religiosidade aumentaram consideravelmente nas últimas décadas, evidência observada no Brasil pela edição, em 2007, de um suplemento exclusivo sobre o assunto no Archives of Clinical Psychiatry (São Paulo) 74 , dando continuidade às publicações até os dias atuais [75][76][77][78][79] . Analogamente, instituições acadêmicas passaram a desenvolver atividades de ensino e treinamento que valorizam as dinâmicas espirituais e religiosas na saúde integral dos pacientes, incorporando conceitos da metaantropologia ou antropologia espiritual à formação dos profissionais da saúde, ampliando a compreensão da natureza biopsicossocioespiritual humana e seu processo de adoecimento [80][81][82][83][84][85] Engana-se quem despreza a incorporação desses contributos filosóficos, vitalistas e espirituais à prática médica moderna, pois, além de incrementar a resolutividade das doenças e tornar a relação médico-paciente mais humanizada, amplia o entendimento do processo integralizante do adoecimento humano (corpo-menteespírito), aspectos bastante valorizados em pesquisas que levantaram os motivos da procura pela população e pela classe médica por terapêuticas não convencionais [88][89][90][91][92][93] .…”