Electroencephalographic measurement of possession trance in the field

Oohashi, Tsutomu; Kawai, Nobuyuki; Honda, Manabu; Nakamura, Satoshi; Morimoto, Masako; Nishina, Emi; Maekawa, Tadao

doi:10.1016/s1388-2457(02)00002-0

Cited by 87 publications

(40 citation statements)

References 17 publications

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“…However, contrary to the cases reported by Oohashi et al 19 and Delorme et al 18 , we found no between-group difference in alpha power during the mediumistic communication.…”

Section: Discussioncontrasting

confidence: 99%

“…These findings corroborate with previous studies that have suggested an association of mediumistic and spirit possession experiences with greater theta and beta power 18,19 , as well as an association of dissociation with greater theta power 9,10 . However, contrary to the cases reported by Oohashi et al 19 and Delorme et al 18 , we found no between-group difference in alpha power during the mediumistic communication.…”

Section: Discussionsupporting

confidence: 92%

“…Although the between-group difference was not statistically significant, we noted greater prevalence of slowing of EEG background activity in mediums compared to non-medium controls, replicating the findings of Hageman et al 20 and Oohashi et al 19 . Klimesch 32 states that during the performance of a cognitive task there may be phasic changes on the EEG background activity and that a phasic slowing of the alpha rhythm reflects engagement of attentional neural processes, whereas a phasic acceleration of the alpha rhythm reflects engagement of memory mechanisms.…”

Section: Discussionsupporting

confidence: 89%

“…Replicating the few available prior EEG studies on this research field 18,19 , we observed that mediums had greater theta and beta power during the anomalous sensorial experience compared to non-medium controls. The lack of reduction in frontal interhemispheric and frontal-posterior coherence in mediums group during the alleged mediumistic communication clearly differs from the coherence pattern reported in pathological dissociation 13 and during the hypnotic state 17 .…”

Section: Discussionsupporting

confidence: 72%

“…In the same article, they reported the finding that gamma and beta waves were the frequency bands that could differentiate mediumistic communication and mental tasks of perception. In other study from Indonesia (possession trance during a religious ritual), Oohashi et al 19 reported a case of intense increase of theta and alpha power during the possession trance state (without ictal EEG pattern), persisting in the recovery (post-trance) phase, which was not the case in the control participants. Likewise, in a Brazilian study, Hageman et al 20 analyzed nine Brazilian Spiritist mediums EEG and found an absence of epileptic discharge on the EEG during mediumistic communication, as well as a slowing of background activity in six participants.…”

Section: Introductionmentioning

confidence: 86%

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

Bastos¹,

Bastos²,

Osório³

et al. 2016

Arch. Clin. Psychiatry (São Paulo)

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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

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“…However, contrary to the cases reported by Oohashi et al 19 and Delorme et al 18 , we found no between-group difference in alpha power during the mediumistic communication.…”

Section: Discussioncontrasting

confidence: 99%