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:
_________
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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