Espirituialidades e Sociedade



Notícias :

Pesquisa observa atividade cerebral de médiuns durante psicografia

 

 



17/11/2012

 

Pesquisa observa atividade cerebral de médiuns durante psicografia
Resultado mostra diminuição de fluxo sanguíneo em áreas inesperadas. Motivo é desconhecido, mas merece ser aprofundado, defende autor.


O artigo "Neuroimaging during Trance State: A Contribution to the Study of Dissociation", de Julio Peres, Alexander Moreira-Almeida e outros três autores, foi publicado no periódico PLOS ONE: http://dx.plos.org/10.1371/journal.pone.0049360 - conforme informou-nos o colega da Liga de Pesquisadores do Espiritismo, Alexandre Caroli.


O portal do grupo Globo na Internet, G1, também trouxe a notícia sobre o lançamento, conforme transcrevemos abaixo:


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Cientistas da Universidade de São Paulo (USP), da Universidade Federal de Juiz de Fora (UFJF) e da Universidade Thomas Jefferson, nos EUA, mediram as atividades cerebrais de dez médiuns brasileiros enquanto faziam psicografia, ou seja, enquanto, segundo acreditam, um espírito supostamente escrevia um texto usando suas mãos.

Eles compararam os resultados da ação de psicografar com a atividade cerebral enquanto redigiam um texto fora do estado de transe, isto é, de “próprio punho”.

A equipe liderada por Julio Peres, do Instituto de Psiquiatria da USP, usou voluntários que têm entre 15 e 47 anos de experiência em psicografia. Eles foram divididos em dois grupos – mais e menos experientes.

Para verificar a atividade cerebral dos dez médiuns, os cientistas injetaram neles um marcador radioativo que permite checar a intensidade dos fluxos sanguíneos em diferentes áreas do cérebro por meio de tomografia.

Os autores afirmam que os médiuns experientes apresentaram níveis mais baixos de atividade durante a psicografia, em comparação à escrita normal, justamente em áreas frontais do cérebro associadas ao planejamento, raciocínio, geração de linguagem e solução de problemas. De acordo com os cientistas, isso pode refletir a ausência de consciência durante a psicografia.

Os psicógrafos menos experientes, por sua vez, tiveram atividade mais intensa nessas mesmas áreas enquanto psicografavam, ainda que também inferior à registrada durante a escrita fora de transe. Segundo os pesquisadores, este fato poderia estar relacionado com uma tentativa “mais esforçada” dos médiuns menos experientes de fazer a psicografia.

Textos

Os autores ainda analisaram os textos produzidos e concluíram que aqueles psicografados resultaram mais complexos que os produzidos em estado normal de vigília, especialmente entre os médiuns mais experientes. Seria de se esperar que isso exigisse mais atividade em áreas frontais e temporais do cérebro, mas não foi o que os cientistas observaram.

De acordo com Peres, não há ainda uma explicação exata para esses resultados, mas eles merecem um aprofundamento. Uma possibilidade é que, como a atividade nas partes frontais do cérebro diminui, outras zonas, relacionadas à criatividade, ficam mais desinibidas. O estudo foi publicado nesta sexta-feira (16/11/2012) no periódico científico online "PLOS ONE".

Fonte: http://g1.globo.com/ciencia-e-saude/noticia/2012/11/pesquisa-observa-atividade-cerebral-de-mediuns-durante-psicografia.html

 

Abaixo o resumo do artigo (Abstract) original citado e a introdução, conforme publicado - em inglês

- clique aqui e leia o artigo completo (em inglês) -



Julio Fernando Peres 1,2,3*, Alexander Moreira-Almeida 4, Leonardo Caixeta5, Frederico Leao3, Andrew Newberg 1,2,6

1 Division of Nuclear Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America,
2
Center for Spirituality and the Mind, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America,
3
PROSER – Institute of Psychiatry, Universidade de Sao Paulo, Sao Paulo, Sao Paulo, Brazil,
4
Research Center in Spirituality and Health, School of Medicine, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil,
5
School of Medicine, Universidade Federal de Goias, Goiania, Goias, Brazil,
6
Myrna Brind Center for Integrative Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America

Abstract

Despite increasing interest in pathological and non-pathological dissociation, few researchers have focused on the spiritual experiences involving dissociative states such as mediumship, in which an individual (the medium) claims to be in communication with, or under the control of, the mind of a deceased person. Our preliminary study investigated psychography – in which allegedly “the spirit writes through the medium's hand” – for potential associations with specific alterations in cerebral activity. We examined ten healthy psychographers – five less expert mediums and five with substantial experience, ranging from 15 to 47 years of automatic writing and 2 to 18 psychographies per month – using single photon emission computed tomography to scan activity as subjects were writing, in both dissociative trance and non-trance states. The complexity of the original written content they produced was analyzed for each individual and for the sample as a whole. The experienced psychographers showed lower levels of activity in the left culmen, left hippocampus, left inferior occipital gyrus, left anterior cingulate, right superior temporal gyrus and right precentral gyrus during psychography compared to their normal (non-trance) writing. The average complexity scores for psychographed content were higher than those for control writing, for both the whole sample and for experienced mediums. The fact that subjects produced complex content in a trance dissociative state suggests they were not merely relaxed, and relaxation seems an unlikely explanation for the underactivation of brain areas specifically related to the cognitive processing being carried out. This finding deserves further investigation both in terms of replication and explanatory hypotheses.


Citation
:


Peres Julio Fernando, Moreira-Almeida A, Caixeta L, Leao F, Newberg A (2012) Neuroimaging during Trance State: A Contribution to the Study of Dissociation. PLoS ONE 7(11): e49360. doi:10.1371/journal.pone.0049360



Introduction

Dissociation is typically defined as the lack of normal integration of thoughts, feelings, and experiences into consciousness and memory [1]. The idea that traumatic experiences cause dissociative symptoms is a recurrent theme in clinical and neuroimaging literature, and some of the cognitive phenomena associated with dissociation appear to be dependent on the emotional or attentional context [2], [3]. Although non-pathological dissociation is quite common in the general population, dissociative experiences are mostly studied as a risk factor for dissociative pathology [4], [5]. Spirituality and religiousness have been shown to be highly prevalent in patients with schizophrenia and dissociative symptoms [6]. However, the varying methodological issues and discrepancies among the studies developed so far make it difficult to articulate a comprehensive framework for brain activity and cognitive mechanisms in pathological and non-pathological dissociation.

Although the nature of the mind and its relationship with the brain is still one of the most challenging issues for science [7]–[10], assumptions made in this respect are the cornerstones guiding therapeutic interventions [11]–[13]. This study addresses important theories underpinning creativity and include religious and spiritual experiences. The American Psychiatric Association [14] pointed to the need for more research in this field by recognizing the non-diagnostic (non-pathological) category of “Spiritual and Religious Problems” in the DSM-IV, thus healthy forms of dissociation [15], [16] may be distinguished from pathological ones [2], [5].

Mediumship, a spiritual phenomenon that has often been reported throughout human history, is defined as an experience in which an individual (the medium) claims to be in communication with, or under the control of, the mind of a deceased person or other nonmaterial being [17]. Mediumistic experiences are usually dissociative, such as motor, sensory or cognitive automatisms (e.g. hearing spirits or reporting body movements or thoughts caused by spirits), and alternate identity or possession). Therefore it is no surprise that the study of mediumistic experiences was crucial to the development of ideas concerning unconscious and dissociative processes. Pierre Janet's classic 1889 study of dissociation examined several mediums; Carl Jung's doctoral thesis was a case study, and William James did meticulous research on the medium Leonore Piper [18], [19]. There has been a trend to divide dissociation in two broad categories: detachment (a sense of separation from the self or the world) and compartmentalization (inability to deliberately control actions or cognitive processes that would normally be amenable to such control) [20]. Although it sometimes involves detachment too, mediumship usually relates to the compartmentalization subtype.

Psychography is one of the many possible dissociative forms of mediumistic expression [17]. “Writing mediums” or psychographers claim that they write under the influence of spirits, and some pyschographed writings have had a major impact in different communities around the world. Brazil's most significant and prolific psychographic medium, Chico Xavier, whose education ended with elementary school, produced over 400 books of automatic writing spanning a wide range of styles and subjects, selling several million copies, with all copyright earnings donated to charity [21], [22].

A study of the mental health of 115 spirit mediums [17], [23] found that subjects had high socio-educational levels, showed low prevalence of psychiatric disorders, and were well adjusted socially compared with the general population. Their experience of mediumship was distinct from dissociative identity disorder. Nevertheless, few studies have investigated the neural substrates underlying dissociative states of consciousness related to religious experiences [24]–[26]. In one previous neuroimaging study of glossolalia – a trance-like state with vocalizations that sound like language but lack clear linguistic structure – subjects were found to have reduced activity in the left caudate nucleus and the right prefrontal cortex, along with increased activity in the superior parietal lobes [25]. Neurofunctional research on sensitive experiences such as religious ones requires specific methods that do not adversely affect volunteers' performance [27].

Like the glossolalia study, the present study utilized single photon emission computed tomography (SPECT) to measure regional cerebral blood flow (rCBF), which is closely correlated with brain activity. We used the SPECT neuroimaging method for this study because it enables researchers to maintain a suitable environment free of distracting/ansiogenic effects for subjects performing complex tasks requiring silence and concentration. To our knowledge, there have been no previous studies of the association between claimed mediumistic dissociative states and specific CBF alterations.

Based on our prior research on related practices such as meditation and prayer, we focused primarily on the prefrontal cortex and anterior cingulate gyrus since both are known to be involved in the brain's attentional network [24], [25]. Furthermore, these areas are involved, along with Broca's area, in the production of speech. We also found evidence of changes in thalamic activity in limbic structures such as the hippocampus, and the superior temporal region is involved in a number of processes including language reception. The precentral gyrus may be involved in the motor function related to writing. Therefore, our hypothesis-driven analysis focused on these regions.

We studied the neurophysiological nature of dissociative mediumship in psychography as measured by changes in rCBF. During psychography, individuals write legible structured narratives but often claim to be unaware of the content or grammar of the written text. The present study aims to determine whether this type of dissociative trance state is associated with specific alterations in brain activity that differ from those found when writing normally, i.e. not in a dissociative trance state. Since psychographed contents feature complexity and planning, our a priori hypothesis was that the areas involved in cognitive processes while writing consciously, such as reasoning and planning content, would show similar activation during mediumistic trance.

 

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