Neuroanthropology of shamanic trance: a case study with a ritual specialist from Mexico

In Mexico, shamans are recognized for the gift of entering a deep trance that allows them to know the origin of the diseases and conflicts that afflict people. They commonly treat patients through limpias (cleansing) to extract negative elements sent by a witch or that were “collected” in places that harbor “evil winds.” We present a case study of an 81-year-old Mexican shaman who noticed her gift in childhood. Electroencephalographic recordings were made while the shaman performed three activities: reading cards to diagnose a patient and answer the questions he posed; limpia with chicken eggs, stones, and bells to absorb adverse “things”; and the incorporation trance through which the deceased is believed to occupy the shaman’s body to use it as a communication channel. Alpha activity was observed when concentrated, suggesting a hypnagogic-like state. Predominant beta and gamma oscillations were observed, suggesting a potential plastic phenomenon that modulates the assimilation of external and internal referents guiding temporal schemes for action, attention, and the integration of mnemonic, sensory, and imaginative elements. We used a neuroanthropological approach to understand shamanic trance as a biological potential of the human brain to induce non-ordinary states of consciousness linked to cultural beliefs and practices.

1 Introduction

For decades, anthropologists and ethnologists have used the term “shaman” interchangeably to refer to people believed to be endowed with particular characteristics, specifically the ability to access a part of reality hidden from most human beings. On behalf of the community they serve, and with the belief that they have the help of allied spirits or guardians, they enter what appears to be a deep trance or altered state of consciousness through which they experience what is perceived to be the establishment of relationships with immaterial entities to alter the order of the cosmos according to their interest or desire (Hultkrantz, 1973). As expressed by the philosopher Mircea Eliade (2013), the term “shaman” has been extended and applied to studies of religious history in several cultures, and similarities have been proposed between so-called “shamans” or “ritual specialists” throughout the world (Winkelman, 1990).

In Mexico, shamans are recognized for their ability to experience non-ordinary states of consciousness that allow them, through divination using various means (deck of cards, eggs, corn, water, copal or candles, to name a few), to discover the origin of diseases and conflicts that afflict the people who consult them. Based on auscultation or prediction, the patient is treated through a procedure called “limpia” (cleansing) whose function is to extract from the body the negative energies sent by a witch or that were “collected” in places that harbor “malos aires” (bad winds). The patient’s body can be literally swept with aromatic herbs, candles, and chicken eggs. In particular, the latter are used for diagnosis; the eggs are broken or poured into a glass of water and “read,” that is, the visible signs are interpreted, but information is also received by virtue of the communication that the shaman establishes with their guardians, a capacity that they attribute to “el don” (the gift), having been designated by some divinity to carry out the work of fortune tellers, healers, and spiritual guides (Fagetti, 2015).

Shamanic trances have been considered states of “concentration” during which those chosen receive messages: visual or auditory perceptions that are continually experienced in divination and healing. Practices related to trances would imply cultural adaptations, which favor the expression of the biological potential of the human brain to induce non-ordinary states of consciousness (Dobkin de Rios and Winkelman, 1989). Winkelman (2000, 2010) proposes that these trances depend on an integrative mode of consciousness, a mental state typical of shamanic practice. The author suggests that the ontological and functional bases of this state come from the functional integration of information from multiple synapses distributed in different brain regions. Because the universal principles of the healer–patient transference are implicit in therapeutic relations, Winkelman maintains that the integration of neural information allows the shamans – among other aspects of their work – to establish a deep connection with the people who require their help.

To our knowledge, there are no experimental reports on the brain function underlying shamanic trance, although some exist on states of consciousness possibly similar to this trance. Most of these reports come from electroencephalogram (EEG) recordings that indicate five waves or signals with different frequencies (Hertz) associated with differentiated physiological, cognitive, and behavioral states and processes: delta (0.5–4 Hz) associated with deep sleep; theta (4–8 Hz) with basal sleep activity; alpha (8–13 Hz) with wakefulness at quiet rest; beta (13–30 Hz) with conscious wakefulness; and gamma (>30 Hz) with conscious perception, memory, and complex thinking (Malik and Ullah, 2017; Chaddad et al., 2023). Transcendental meditation is associated with brain activity that oscillates between alpha and beta waves (Lyubimov, 1999). Hypnosis has been associated with theta and alpha frequencies, although gamma activity is particularly recurrent in people with high hypnotizability (De Pascalis and Santarcangelo, 2020; Callara et al., 2023); in Tibetan Buddhist monks, an increase in gamma frequencies has been reported during compassion meditation (Lutz et al., 2004). Other neuroimaging techniques have been used in some reports. Buddhist meditators evaluated by single-photon emission computed tomography (SPECT) showed increased blood flow in the frontal cortex, while it decreased in the parietal region, and these conditions were associated with increased self-control and sensitive-cognitive processing and a sense of inner freedom (Hankey, 2006). An interesting case is that of a woman with voluntary out-of-body experiences and whose functional magnetic resonance imaging (fMRI) indicated the activation of supplementary motor and orbitofrontal regions related to action imagery and cognitive monitoring (Smith and Messier, 2014).

Given the complexity of the shamanic trance, we propose to explore it from a neuroanthropological perspective, that is, to consider that the brain function underlying a behavior or cognitive expression not only involves the evolutionary and physiological properties of the human nervous system but also the history, dynamics, cultural beliefs, and practices that define a person and their community and that provide the nervous system with the necessary information for the person to interact with and interpret their environment (Lende and Downey, 2012a,b). To do this, we show the case of a ritual specialist or shaman with a long career. While we show some specific neurobiological and behavioral findings here, the research is part of a larger work described by the anthropologist Toriz (2018).

2 Method

2.1 Participant description

Lupita is an 81-year-old ritual specialist who lives in the state of Puebla, Mexico. According to Fagetti (2015), she was still a child – around 9 years old – when she began to have her first experiences with the shamanic gift, such as being able to “see” who was going to die, when, and under what circumstances. It was her grandmother who told her that she would perform a ritual to “open her brain,” that is, perform what is known as shamanic initiation.

According to Eliade (2013), the “ecstatic” election or first manifestations of the shamanic gift are generally followed by a period of instruction during which the neophyte is properly initiated by an ancient master. It is then when the future shaman must learn to master their mystical techniques and assimilate the religious or mythological tradition of the corresponding region and population. Lupita began to heal when her grandmother had already died; she died in Lupita’s arms at the age of 80. Like her grandmother, throughout her life, Lupita has worked as a midwife and healer. She treats her patients by reading cards and performing limpias. She cures conditions that traditional indigenous Mexican medicine considers “affections of the spirit” because they damage the energetic–spiritual part of the human being. They involve the loss of the spirit, such as susto (scare) or the penetration into the body of a pernicious energy, as in the case of “air,” when, for example, the spirit of a deceased person lodges in the body; the mal de ojo (evil eye) or the force that a person gives off, involuntarily, through their gaze; and damage from witchcraft or any type of curse perpetrated against someone, which causes various signs and symptoms (Fagetti, 2015).

Lupita also has the gift of contacting and interacting with deceased people to “give them light” – that is, to guide those spirits who, after dying, cannot find the way to eternal rest. Lupita says that much of her work is done under the protection of her guardians, the spirits of two people, whom she calls Huichil and Lirio, who lived in Mexico before the Spanish Conquest and who were dedicated to healing at that time (Fagetti, 2015; Toriz, 2018).

2.2 Assessment

Accompanied by the research team, Lupita went to the Sleep Disorders Clinic of the Metropolitan Autonomous University, Iztapalapa Unit. There, a relaxed and comfortable atmosphere was established, and the recording instruments and their use were shown and explained to her. Commonly, shamanic practices are performed in the shaman’s own environments and spaces. However, Lupita usually performs her activities in various contexts, namely, her own consulting room, her patients’ homes, or public spaces, when she is invited to an event, which is why her stay at the clinic was not experienced by her as a space outside her usual praxis.

For the EEG recording, a Cadwell Easy II device was used, with a longitudinal assembly using conventional electrodes with a gold cup, under awake conditions and following the International 10–20 System and recommendations of the International Federation of Societies of Clinical Neurophysiology, with 1 to 50 filters and 7 sensitivity, equivalent to 50 μV (San-Juan and Bermeo-Ovalle, 2023).

During the EEG, Lupita performed several tasks or activities, typical of her gift and shamanic practice, aimed at three participants who were part of the research team. The first activity (approximately 14 min) was a card reading with a Spanish deck. With this, she sought to answer three questions individually generated by the participant according to their own doubts and interests. The participant was sitting in front of a table on which Lupita placed a handkerchief and, on top of it, the deck of cards to perform the reading. After unfolding the deck and observing it carefully, she indicated to the participant her interpretation in response to each of their questions.

The second activity was a limpia (approximately 8 min). Lupita inherited from her grandmother a set that she covers with a red handkerchief – the contents of which she cannot reveal – and that represents the gift. With it, she covered the participant’s entire body, from head to toe, to eliminate possible damage. She “cleaned” the participant with a chicken egg and a crystal stone to see specific details about this person and give them “light” and used a small metal bell to restore their positive energy. She then ran her hands over the participant’s body. Finally, Lupita carefully observed the surface of the egg to “see” the problems that afflicted the participant and communicate them.

The third activity (approximately 14 min) consisted of an “incorporation trance.” The shaman can serve as a channel allowing the “entry” of the spirit of someone who has died. It also constitutes a shamanic technique through which an ancient healer or a Catholic saint occupies the shaman’s body and “performs” the diagnosis and limpia. A ritual specialist who has participated in Fagetti (2015) research explains that, when one of his guardians “arrives,” his “spirit comes out and stays above, floating.” In the case of a deceased person, this is an opportunity for them to come forward and speak to their relatives. As for the guardians of the ritual specialist, they are the ones who interact directly with the patient. Through this type of trance, Lupita sought to establish contact with a deceased man known to the third participant so that they could interact and have a dialogue, in addition to giving him peace and helping him find the light. During the trance, Lupita was sitting with her eyes closed to facilitate the link with the spirit and allow it to enter her body. Once inside, and using Lupita’s body and voice, this spirit and the participant spoke.

The three activities performed during the EEG were video-recorded and subsequently reviewed and analyzed to define three simultaneous aspects: behavioral expressions, movements, or postures; the linguistic aspects or words expressed by Lupita and the participants; and the EEG. For interpretation, the three aspects were grouped into action units or time periods defined by the meanings of each performed action. Once the action units were reviewed, the analysis integrated the “explanation” aspect or meanings defined by Lupita herself in subsequent interviews conducted in her consulting room. Lupita and the researchers watched the videos together, and based on the defined action units, Lupita provided the explanation or meanings of each of them.

The times and sequences of the behavioral, linguistic, and EEG expressions for action units involving the three activities are shown in Figure 1.

Figure 1

Figure 1. Time and sequence of behavioral, linguistic, and EEG recording for action units involving the three activities performed by the participant.

3 Results

Observations and measures for each of the three activities (card reading, limpia, and incorporation trance) are presented in the three tables. Each table shows the different sections shaping the activity, from initial preparation to conclusion. Each section indicates the action units and the EEG time in which they were expressed. Each action unit illustrates the associated behavioral expressions, linguistic aspects, and EEG signals. In addition, it includes the explanation that Lupita gives for such actions.

3.1 Card reading

Lupita explains that, since her grandmother “paved the way for her,” she can read cards in a state of introspection achieved through prayers and entrustments to Catholic saints or their guardians, Huichil and Lirio (see Table 1).

Table 1

Table 1. Behavioral expressions, linguistic aspects, electroencephalographic (EEG) recording, and explanation of the actions concerning the card reading.

3.2 Limpia

Lupita prepares by asking her guardians for support and paying attention to what she is seeing (see Table 2).

Table 2

Table 2. Behavioral expressions, linguistic aspects, electroencephalographic (EEG) recording, and explanation of the actions concerning the limpia.

3.3 Incorporation trance

The trance is believed to allow Lupita to enter an invisible world where the dead live and she can communicate with them (see Table 3).

Table 3

Table 3. Behavioral expressions, linguistic aspects, electroencephalographic (EEG) recording, and explanation of the actions concerning the incorporation trance.

4 Discussion

During the card reading, the EEG predominantly showed beta activity when Lupita was listening to the participant; beta signals also occur during transcendental meditation (Lyubimov, 1999) and perhaps involve phonological and semantic processes (Spironelli et al., 2013). In Lupita’s case, beta activity may have been necessary for her to understand the participants and their questions about the cards. Gamma activity was also recorded with frequencies up to 60 Hz, suggesting complex cognitive processes involving attention and memory for both sensory and non-sensory aspects (Jensen et al., 2007). In fine EEG studies, it has been suggested that this rapid activity originates in the hippocampus and is the result of interactions of the hippocampus with the neocortex, which may explain memory consolidation and explicit learning processes (Pedrosa et al., 2022), necessary to integrate previously known and recently learned elements shaping new connections. The cognitive complexity involved in card reading perhaps corresponds to observing the arrangement of the cards on the table, a moment in which Lupita “listens,” as she explained, to her guardians, who suggest the answers to the questions asked by the consultant.

Regarding the limpia, particularly during the initial preparation, alpha activity involving resting and relaxed but attentive states of wakefulness was observed (Sanei and Chambers, 2007). Some authors have suggested that alpha activity is the first EEG element affected by preparation for a non-ordinary state of consciousness – for example, in hypnosis or in transcendental meditation that elicits a sensation of completeness in practitioners with several years of experience (De Pascalis and Santarcangelo, 2020; Callara et al., 2023). This alpha state would suggest that practice and training configure a state of consciousness similar to the transition to stage 1 sleep, with certain similarly hypnagogic effects (Lyubimov, 1999; Hankey, 2006). In Lupita, these effects can be understood within the framework of the body movements and postures that she performs sitting and that are meant by her as a form of concentration and request for support from her guardians [Huichil and Lirio], as well as being able to “see” if the participant has some serious damage. In contrast, during the limpia process itself, after preparation, the EEG showed predominantly gamma activity. This could represent a particular sensitivity of Lupita to evoke and sustain such brain function, similar to people with high hypnotizability (De Pascalis and Santarcangelo, 2020; Callara et al., 2023). It could also represent complex cognitive functions that, in the case of Lupita, include an understanding toward the patient and the intention for well-being translated into the use of her gift and in practices such as collecting, with the egg, the “bad things” that the patient may have, observing what they needs in the stone, or reestablishing their positive energy with the bells and hands. It is notable that gamma activity has been observed in Buddhist monks when practicing compassion meditation, which, similarly to Lupita’s practices, involves an evident intention and disposition of well-being toward others (Lutz et al., 2004). At the end of the limpia, after reading the egg and saying goodbye to the participant, the EEG recorded 20 Hz beta activity, typical for normal active wakefulness. The EEG during the limpia could represent a particular state of concentration that Lupita enters at will. The alternation of gamma and beta frequencies could signify a plastic phenomenon that modulates, through excitatory and inhibitory processes, conscious attention toward external body referents and those inner and abstract ones (Bibbig et al., 2002).

Beta and gamma alternation was also observed during the “incorporation trance,” although predominantly high-frequency gamma activity (up to 80 Hz) was recorded, particularly at the time when Lupita was communicating with the deceased. In Mexican shamanic practices, incorporation implies that the shaman’s spirit “goes out and remains above, floating” (Fagetti, 2015), a similar description to that reported by a woman with the ability to leave her body at will (Smith and Messier, 2014). However, unlike this last case in which the out-of-body experience was associated with brain functions involved in motor monitoring and imagination, Lupita (and shamans in general) is not aware of her body or the interaction she maintains with the participant; it is the spirit of the deceased, his consciousness, that speaks through Lupita. In the end, when saying goodbye and once the deceased man left Lupita, low-frequency alpha activity was recorded, which may be associated with the resting wakefulness that precedes sleep, as has been observed in meditators (Cahn and Polich, 2006) and that coincides with Lupita’s exhaustion at the end of this activity.

Lupita’s EEG showed predominantly gamma activity alternating with beta activity during the three performed actions. These oscillations are consistent with what was observed in Tibetan Buddhist monks while practicing compassion meditation (Lutz et al., 2004) and in states of hypnosis in people with high hypnotizability (De Pascalis and Santarcangelo, 2020; Callara et al., 2023). Such oscillation perhaps represents a conscious and equanimous preparation elicited by neuronal assembly and plastic activity in the cortex, indicating temporal schemes of action, rapid and flexible thinking, attention, and integration of mnemonic, sensory, and imaginative elements (Fries et al., 2007). Moreover, it may involve training in the case of meditation and induced suggestion in the case of hypnosis, and both circumstances may be present in Lupita’s shamanic practice. However, unlike contemplative practices and hypnosis, shamanism implies a gift understood from worldviews and conceptions that make the shaman a vehicle. Thus, said brain function can refer to the integrative mode of consciousness or mental state typical of shamanic activity, as suggested by Winkelman (2010). Following Dobkin de Rios and Winkelman (1989), this mental state would imply a biological potentiality adapted to Lupita’s culture and from which the meanings of her practices, such as “seeing” what is bad about the patient, communicating with her guardians, or speaking with a deceased person, have a psychophysiological correspondence. Furthermore, this brain function implies training and practice, as has been suggested for Buddhist monks (Cahn and Polich, 2006), that, in the case of Lupita, although attributable to her gift, are also guided by her guardians, having been trained by her grandmother since she was a child and having constantly practiced since then.

Our work proposes a neuroanthropological approach to understanding shamanic trance. We understand that pure psychophysiological or anthropological analysis is insufficient and that dual interpretations are necessary to comprehend human behavior manifested in specific spaces (Pritzker et al., 2023). Furthermore, as proposed in the case of Candomblé, in Brazil (Seligman, 2010), we understand that the healer (or shaman) represents a “self” that crosses mind–body interactions and that cultural practices can influence these interactions within healing dynamics. Therefore, as proposed by Lende et al. (2021), we realized an interdisciplinary methodological triangulation to link observations made in the field with evaluations from an experimental laboratory. In this way, a conceptual triangulation between anthropology, psychology, and neuroscience is possible to jointly interpret the results from three disciplinary approaches that denote the mental, physical, and social aspects of the phenomenon. To complement our interpretation, we included what Lende et al. (2021) call “Say” and “Do,” that is, Say, which corresponds to the participant’s explanations, in their own words, about how they interpret what happens and why, and Do, which corresponds to the practices performed in specific contexts.

Our proposal is an exploratory case study with several limitations: EEG interpretations require additional analyses to define brain topography or use control situations and larger samples to contrast our findings. However, although various shamanic practices share common elements, they also take into account the particularity of each shaman’s history, community, and beliefs. A future neuroanthropological path could encompass more and varied elements of the shaman’s own culture – for example, the participant or patient being a member of the shaman’s community with a greater affinity of traditions and beliefs. Currently, it would be possible to adopt ambulatory methods, such as portable EEG instruments, to perform recordings in the shaman’s own spaces and thus achieve more ecological information (Pritzker et al., 2023). Likewise, given that the shaman’s work fundamentally involves healing in the shaman–patient relationship, the possible electroencephalographic synchronization between both and during the process could be investigated and integrated with the people’s narratives of healing.

5 Patient perspective

Throughout her more than 20 years of research on shamanism in Mexico, Antonella Fagetti and Lupita have formed a bond of trust, thanks to which, after having our objectives and procedures explained to her, she agreed to participate in this research and provided her informed consent. Lupita has always shown interest in openly collaborating in any exercise that, as mentioned, can contribute to the clarification of the mental processes involved in shamanic praxis. The three participants in the activities performed by Lupita were members of the research team and agreed to voluntarily participate because of their interest in answering their own questions. The research followed the guidelines proposed by the Declaration of Helsinki and was approved by the ethics committee of the Universidad Autónoma Metropolitana, Unidad Iztapalapa.

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethics statement

The studies involving humans were approved by Ethics Commission, Universidad Autónoma Metropolitana, Unidad Iztapalapa. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.

Author contributions

HT: Conceptualization, Data curation, Investigation, Methodology, Writing – original draft, Formal analysis, Writing – review & editing. AF: Conceptualization, Formal analysis, Investigation, Methodology, Writing – original draft, Funding acquisition, Supervision, Writing – review & editing. GT-P: Formal analysis, Funding acquisition, Methodology, Writing – original draft, Resources, Writing – review & editing. RM: Formal analysis, Funding acquisition, Methodology, Resources, Writing – review & editing, Conceptualization, Data curation, Investigation, Project administration, Supervision, Writing – original draft.

Funding

The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.

Acknowledgments

The authors appreciate the valuable experience shared by Lupita and the three participants in a kindly and animated means.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

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