A small exploratory study suggests that people who report experiencing mediumistic trance states appear to exhibit different brain connectivity patterns compared to people who engage in prayer. The researchers propose that the brain activity recorded during these episodes suggests altered states of consciousness that do not resemble typical sleep or mental illness. The findings were published in the journal Psychiatry Research: Neuroimaging.
Mediumship refers to the practice of subjectively believing that a person is acting as a vessel of communication from a source that exists outside of physical reality. Many people report these experiences as a sudden change in consciousness, allowing them to hear or see purported spiritual beings. Although personal accounts of such events are common in many cultures, attempts to study physiological processes through modern neuroscience represent a relatively new and highly complex frontier.
Previous neuroimaging studies have observed basic brain activity in religious practitioners by observing localized hot spots. But researchers want to understand exactly what happens in broader brain networks when people voluntarily enter a state called trance. Rather than focusing on isolated regions, they are trying to identify how different regions work together.
Lead author Jessica Placido, a researcher at Brazil’s Baiana School of Medicine and Public Health, investigated this phenomenon with colleagues from several Brazilian universities. They specifically investigated functional networks in the brain. This analytical approach treats the human brain as a highly interconnected system.
Traditional electroencephalography (EEG) measures the brain’s electrical output through sensors placed directly on the scalp. Older experiments typically measured the raw power of brain waves at specific, isolated locations. Placido and her team chose a dynamic network approach to see how these signals relate to each other.
Functional network analysis maps how different parts of the brain synchronize their activity over time. The researchers applied a mathematical framework called graph theory to track this behavior. In this system, electrical readings from each scalp sensor represent individual nodes within a larger web.
The connections between these nodes are called edges. By constantly mapping nodes and edges, scientists create an evolving graph of human cognition. When two distant regions exhibit exactly the same set of electrical changes at the same time, they establish a functional connection.
The researchers conducted a small study using brainwave data collected from just 28 women living in Campo Grande, Brazil. The researchers recruited participants from local centers that practice Spiritism. Spiritualism provides a cultural context in which spirit channeling is a voluntary practice, giving researchers the opportunity to scan subjects in a controlled environment.
Half of the women selected were experienced practitioners who claimed to have been channeling spirits regularly for at least five years. The remaining 14 women served as a control cohort. Although these people attended the same religious centers and shared the same spiritual perspective, they themselves did not act as channels.
The researchers confirmed this distinction by asking participants to fill out a self-report questionnaire called the “Anomalous Experiences Inventory.” The survey tracks how often people claim to have experienced unusual phenomena, such as out-of-body experiences, unexplained intuitions, and apparitions. The moderate group reported a much higher frequency of abnormal experiences compared to the control group.
To begin the experiment, both groups sat quietly with their eyes closed in a dimly lit room for seven minutes. At this initial stage, baseline measurements of resting brain activity were established. Following baseline, the two groups participated in radically different mental and physical tasks.
The moderate group progressed through what was described as a psychophonic trance state. That means they were actively speaking out loud, perhaps in a spirit transmitted through their vocal chords. The control group, on the other hand, listened and participated in the sessions while silently praying. The researchers recorded scalp electrical patterns throughout the simultaneous sessions.
Using the data collected, the team planned multiple frequency bands. The human brain generates several types of radio waves depending on the person’s mental state. They tracked delta waves, which are slow and usually associated with restorative rest, and theta waves, which are slightly faster and associated with deep relaxation.
Scientists also tracked alpha waves, which occur when a person is awake but mentally calm, and beta waves, which are associated with active, focused thinking. To build the network graph, the software looked for matching sequences of electrical spikes and dips across the various sensors. This technique allowed scientists to quantify how long different areas of the brain remained in sync.
When comparing the trance phase to the baseline rest phase, medium showed increased brain connectivity in the delta and theta frequency ranges. Their brain regions synchronized more frequently and maintained their connections over longer periods of time. No such spike in connectivity occurred in the control group.
Increases in both delta and theta brain waves typically indicate the transition from wakeful consciousness to early sleep. However, subjects in the moderate group spoke actively and sat upright during recording. Although the researchers propose that mediumistic trances function as a unique altered state of consciousness that is entirely separate from rest, it is also likely that physical acts such as speaking or changes in breathing influenced these particular readings.
The scientists tracked additional metrics to determine whether the brain was communicating across its halves or whether activity was localized. While in a trance, mediums experienced alpha wave changes. The left hemisphere changed its behavior and established an equal balance of connections across its own side and the right hemisphere.
The left side of the human brain normally processes language formation, language comprehension, and spoken language. During the session, the mediums were actively vocalizing their messages, which logically indicated a change in left hemisphere activity. But silent prayer also makes heavy use of these same brain areas.
Scientific literature shows that prayer involves inner dialogue and social storytelling, which activates similar cortical networks. Despite their redundant reliance on language networks for prayer, the control group did not show similarly strong changes in the left hemisphere. The researchers suspect that the detected brain patterns may be related solely to the nature of the trance state itself, although sheer differences in vocalizations remain a significant confounding factor.
The non-moderate control group only showed network changes in beta waves. During prayer sessions, the likelihood that one brain region dominated the rest of the network decreased. While they prayed, their brain networks became more universally synchronized.
The researchers acknowledge that the experimental procedure has some major limitations. Because this is a small study of only 28 people, the observed connectivity patterns represent a highly localized sample that will require rigorous replication in the future. Most notably, the two groups differed significantly in their physical output for the specific tasks they performed.
The mediums spoke loudly during the trance, while the controls prayed in complete silence. Physical differences, such as vocalizing a sentence, can cause changes in muscle movement and breathing that can significantly disrupt and affect the raw electrical activity detected by electroencephalography on the scalp. The scientists recommend that future projects ask control groups to perform improvised speech tasks that reflect the physical behavior of channeled messages. This helps eliminate false signals.
Additionally, portable recording equipment had sampling limitations that prevented extraction of the gamma frequency band. Gamma waves are the fastest electrical signals produced by the brain and often deal with intense consciousness. As medical capabilities improve, future researchers will be able to monitor this missing frequency.
Despite these significant confounding factors, researchers argue that a functional network approach provides a productive method for mapping religious experiences. The brain network dynamics observed in mediums do not match the patterns associated with severe psychiatric diagnoses such as schizophrenia. Based on preliminary mapping data, the researchers conclude that suspected mediumship alters brain synchronization in a non-pathological way, even though the exact physiological triggers of these changes are still debatable.
The study, “Brain Functional Network Dynamics in Women Suspected of Psychic Mediumship: A Controlled Study,” was authored by Jessica Placido, Marco Aurelio Vinhosa Bastos Jr., Paulo Roberto Haydams de Oliveira Bastos, Taise GL de O. Tuten, and José García Vivas Miranda. Published in February 2026.
