Calling Down the Gods and Invoking the Spirit: Entertaining the Possibility of Ritual Possession as Discreet Behavior versus Abj

mcrepeau's picture

Michelle Crepeau

Professor Grobstein

Biology 202-Neurobiology and Behavior

8 March, 2008


Calling Down the Gods and Invoking the Spirit: Entertaining the Possibility of Ritual Possession as Discreet Behavior versus Abject Mental Disorder


In 2005 the Scott Derrickson film, The Exorcism of Emily Rose, recounted the harrowing story of a young girl’s ordeal with the phenomenon of demonic possession. Opening in the midsts of the immediate aftermath of her death, the film strives to piece together the individual elements that lead to her frightening physical and mental deterioration at the hands of what the clerical elements of the film deign the work of devils and the medical officials diagnose as a severe and debilitating mental illness. The movie itself posits a happy if ambiguous medium between the two otherwise non-interchangeable avenues of dialogue. By probing the depths of the validity of medical conditions, such as epilepsy and Tourette’s syndrome, commonly associated with “possession” type scenarios the film suggests the possibility for valid the existence of evidence that would codify the possession phenomenon as its own unique neurological process independent of chronic mental illnesses. It is this last avenue of dialogue that drew my attention the most and which I retained.

During one of the several trial sequences of the film in which this dialogue is brought to the forefront, an expert on ritual possession is brought to the witness stand and asked to provide evidence in defense of the legitimacy of possession from a neurological and anthropological point of view. The expert proceeds to describe the neurological state of individuals who in tribal religious rituals enter a state referred to as the “possession experience”, an experience which supposedly is signified by particular neurological phenomena distinct from epilepsy or Tourette’s syndrome [1]. If legitimate, this distinct pattern of neurological activity would suggest that some kinds of possession experiences do not arise from chronic mental disorders but from other, more incidental types of human behavior that have an implicit aspect of control or volition associated with them. In other words, if it is true that some types of possession are associated with distinct neurological activity, which resembles non-illness types of activity, then there is the possibility that the experience of possession is not so much the result of mental disease as a kind of distinct human behavior.

However, one must remember that such posits are first and foremost the products of Hollywood and the scientific reasoning therein is implicitly subject to the needs of a marketable plot and not necessarily related to any form of reality. That being said, I nevertheless found the idea that some types of possession, particularly ritualized trance possession, in which the possessed actively seeks the possession experience, could be linked to distinct behaviors in a normative brain to be deeply intriguing. Particularly intriguing was the idea that the behavioral patterns associated with certain types of possession could be the result of activated CPG’s or central pattern generators, which for one reason or another become un-inhibited during the possession ritual. Also, intriguing was the implication of a conscious awareness of the possession experience in the sense that this particular state can be consciously sought and triggered on some level by the activity of conscience, or “I-Function”. Thus, the goal of this discourse is the exploration of the possible neurological and psychiatric evidence that could validate the existence of a discreet possession behavior and codify it as more than just convenient Hollywood pseudo-science.

The classical association between neurological activity and possession type phenomena is that of physiological mental disorder and accompanying symptom, where disorders, such as epilepsy, provide the cause for perceived possession experiences. However, disorders like epilepsy, which are described as “abnormal, excessive, or synchronous neuronal activity of the brain” [2], and which for the sake of this course can be described as miscommunications between corollary discharge units and sensory input/output paradigms, are considered “chronic” , “recurrent unprovoked” occurrences [2]. Epileptic fits can also be confined to definite life stages with little carryover between certain age groups. For instance, epileptic symptoms which may be prevalent during childhood can cease at the onset of adulthood [2] in the same way that all but the most severe types of Tourette’s can. Also, epileptic phenomena, i.e. neurological activity resulting in the kind of seizures associated with epilepsy, can be caused by a variety of impetuses. These impetuses include but are not limited to head trauma, tumor, stroke, poisoning, bacterial or viral infection, and various congenital disorders [2]. Epilepsy is what is known as a divergent condition in which various symptoms and neurological causes produce a vast variety of abnormal electro-chemical brain activities [2]. Such a wide range of symptoms, stimuli, and corresponding neurological activity suggest that there is no one electro-chemical pattern, corollary discharge pattern, or central pattern generator distinct to epilepsy.

Epilepsy can thus be considered as a type of umbrella diagnosis which is used to describe a wide range of “abnormal” activity resulting in the episodic mass loss of conscious, i.e. “I-function” monitored, control over one’s body. However, the optimal words here are phrases such as “abnormal” activity, and the clinical emphasis placed on the chronic, uncontrolled nature of epileptic occurrence. Abnormal here would indicate that the brain activity indicative of epileptic activity is inherently against the normative status of the nervous system and neurological regulation of body behavior. Thus, the word abnormal can be considered to mean “unusual” or even “unnatural” to the proper functioning of the human body, and is thus relegated to the realm of disorder and disease. This idea of the unnatural in relation to situations where epileptic episodes are a result of direct physical trauma and alteration of the nervous system, i.e. damaged tissue, scar tissue formation, etc., is even more clearly suggestive of a neurological “disorder”. However, the term “disorder” and the concept of “abnormal” itself in many ways provide inappropriate connotations. The association of the abnormal and the disordered with the inherently wrong or with that which is not present is incorrect. Abnormal or disordered can also simply mean a change in the ordered structure of the nervous system, or an unusual application of an aspect of the nervous system. Thus, abnormal or disordered activity can also relate to a feature of the nervous system which, although an inherent part of the nervous system, is usually kept inhibited or typically functions in some other respect.

However, whether or not some epileptic activity can arise in part from the abnormal use of neurological mechanisms, the chronic and involuntary nature of epilepsy suggests that it is a phenomenon which occurs without input from the conscious monitor of the “I-function” i.e. there is no conscious choice to produce the outputs or receive the inputs related to the phenomenon. Also, the confined nature of many epileptic occurrences to specific time frames in an individual’s life, i.e. childhood or adulthood, provides certain restrictions as to when possession type experience can occur. However, some types of possession experiences, particularly ritualistic religious possession experiences like those described in The Exorcism of Emily Rose, including Voodoo ritual possession and even Evangelical Revivalist ritual, occur regardless of age, are actively sought out experiences, and are typically unassociated with any diagnosable chronic mental illnesses. Thus, it appears that ritualistic forms of possession, at least, differ from the type of possession experiences associated with more physiological conditions and disorders.

Unlike, the multi-faceted condition of epilepsy under which any and all abnormal neuron-electrical activity is classified, there does exist some tentative studies associated with isolating discreet neurological patterns of activity indicative of the possession experience. For example, in 2002 a research group from the National Academy of Science completed ground breaking research by successfully recording the neurological activity of participants in a Balinese possession trance, or “Kerauhan”, using electroencephalograms (EEG) [3]. The results from these EEG’s recording revealed that during the possession experience the otherwise mentally and physically normative participants experienced brain function that was “altered into an unusual mode” [3]. When compared with control subjects it was revealed that during the possession experience the magnitude of “theta and alpha frequency bands of spontaneous EEG increased significantly”, persisting for several minutes following the experience [3]. Along with increased frequency bands increases in the plasma concentrations of β-endorphin, dopamine, noradrenalin, where also noticed in significant degrees [3]. The group went on to declare that similar possession/trance phenomena, and thus similar discreet possession affiliated neurological patterns, could be detected in neurologically normative people in 90% of all known human societies [3].

However, outside of religious and culturally sanctioned possession rituals is another type of possession phenomena that inhabits an ambiguous limbo space between physiological states of possession experiences and mental disorder. A tentatively added subset of the psychological condition known as dissociative disorder, the Trance and Possession Disorder [4] is classified as type of possession state fundamentally different from both ritualized possession/trance experiences and psychotic disorders, such as multiple-personality disorder and schizophrenia [4]. The definition of this phenomenon includes such aspects as a change in consciousness in which the sense of personal identity is lost, accompanied by a selective focus on certain environmental stimuli, and the execution of certain “stereotyped” movements that are perceived as being beyond one’s control [4]. However, despite the emphatic emphasis that dissociative type possession experiences are fundamentally different from ritualized experienced it seems to me that on many levels they are inherently linked by similar possible neurological mechanisms. For instance, one aspect of the dissociative form of possession is the selective stimuli focus, in which certain stimuli, often auditory, or tactile stimuli, are given disproportionate attention by the conscious seat or “I-Function”. However, this exclusive focus is also characteristic of some ritualized forms of possession or trance states in which features such as meditation, mantra, particular sound frequencies from specific instruments (auditory stimuli), and even some visual stimuli provide the segue into the possession or trance state [3].

Since, in these cases the “I-function” as well as certain regions of the neo-cortex, such as the parietal and temporal lobes specifically [5], seem to become exclusively focused on processing an extremely narrow set of input and/or output it is possible that the “I-function” and/or regions of the neo-cortex temporarily lose control over the regulation of particular types of functions and are effectively removed from service. It is thus possible that what the possession state is in both cases is the removal of “I-function” as well as certain neo-cortical maintained inhibition of central pattern generators. These CPG’s control broad units of motor-neuron circuitry in turn control broad bodily movements of the kind designated as “stereotyped” involuntary motions. Removal of “I-function” moderation may also un-inhibit certain sensory neuron features, such as the random generation of auditory input from the nervous system, or tactile information from the skin. However, since these features are typically kept inhibited corollary discharge reports may be unable to account for them and thus be unable to process them as anything but real external stimuli. Thus, the phenomena of internal voices, or the physical sensation of an additional internal presence may occur. Perhaps there is even an inhibition of certain central pattern generators which effectively “are” the possession experience. However, in order to establish this last conclusion a situation would have to be established in which an isolated human nervous system was systematically stimulated or monitored for the generation of a possession experience type activity. Ethical reasons aside, this situation would be difficult to establish since it is difficult to ascertain whether or not the noted neurological phenomena associated with possession experiences is a single signal pattern or a group of accumulated patterns. It is also difficult to say based on the research done so far if each pattern, if there does exist such a thing, would be the same for each type of ritual possession and for each individual.

The major difference between the dissociative, the ritualistic, and even the epileptic experience of possession is ultimately the idea of intent in both the cases of the dissociative and the epileptic experiences the phenomenon is unbidden and un-desired, chronic and involuntary. In contrast, the ritualistic type of possession whether Balinese, Haitian, or Evangelical is actively sought after and induced by choice. This induction by choice inherently implies the active moderation of the “I-Function” on some level, and thus, a certain degree in active plasticity in how we moderate the avenues of neurological inhibition and focus in our own bodies. The “I-Function” can, it seems, actively remove itself from the picture just as it can be removed unknowingly from the picture under certain conditions. For, the important aspect of the possession experience to keep in mind is that it is described as an experience in those cases at least where there is a certain level of participation or awareness of the phenomenon.

However, the reasons why the “I-Function” can actively participate or why the nervous system may encounter these experiences are vague. Why does this behavior, this possible CPG or possible coordination of CPG’s, however strictly inhibited they may be normally, even exist as a possible behavioral experience? One possible explanation for the existence of, at least the ritualized possession experience is that the possession/trance process activates a reward-generating neuronal cascade [3], which effectively rewards us with endorphin release following its activation. However, for what purpose would this system have been biologically or evolutionarily beneficial as to require encouragement for repeated use? And if the experience is reward generating, then does its improper activation, and sometimes even its proper activation, lead to terrifying, ultimately detrimental experiences, such as what befell Emily Rose?






[1] Derrickson, Scott. The Exorcism of Emily Rose. Produced by Paul Harris Boardman et al. USA 2005



“Epilepsy”, Wikipedia, the Free Encyclopedia. Wikipedia Foundation Inc. 4/7/08. 4/7/08.



“Kavli Frontiers of Science-Symposium Series: Meditation and the Brain”. Japan Society for the Promotion of Science-U.S. National Academy of Science. 12/8-10/2006.


“Dissociative Disorder Not Otherwise Specified: A Clinical Investigation of 50 Cases with Suggestions for Typology and Treatment”. By Philip M. Coons, NI.D.

DISS0CI:1Tl0N.Vol. V. No. 1. December 1992.



“Neurology of Possession”. Numenware, a Blog about Neurotheology.

January 2nd, 2006.




Paul Grobstein's picture

Possession: from epilepsy and culture to the I-function

Lots of interesting issues here. For more on epilepsy and culture, see The Spirit Catches You and You Fall Down and Themes in .... . Its intriguing indeed to go beyond this and try and distinguish various possession states in terms of a closer look at brain activity. And I'm particularly intrigued by the idea that some such states can, and other cannot, be attributed to activity of the I-function itself. "The “I-Function” can, it seems, actively remove itself from the picture just as it can be removed unknowingly from the picture under certain conditions." That is tells us some interesting things about the I-function and its place/role in both the nervous system and behavior.

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