An old practice known as psychomanteum places people before a mirror in a dimly lit room and invites them to watch for whoever might appear. The ritual is presented as a way to communicate with departed loved ones, connecting claims of paranormal contact with grief.

Mirrors are generally made from glass and reflective metal, hardly a secret formula for looking into the afterlife. Yet their reflections can produce strange effects, including tricks that involve human perception and the mind.

In a new study, scientists examined what might influence the likelihood that someone sees a deceased loved one in a mirror. They recruited 30 participants and monitored several personal and environmental factors as the group attempted to peer into another realm.

The researchers were especially interested in participants who experienced something exceptional, such as sensing a presence or seeing a face other than their own. Those events became the central focus of the mirror gazing experiment.

Every participant had previously reported an experience with a ghost. Of the 30 people selected, 15 also had synesthesia, a neurological trait in which senses can become mixed, allowing experiences such as tasting colors or seeing shapes while hearing music.

Synesthesia is not considered a disorder. Instead, it is viewed as a natural variation in how people are wired, although researchers considered whether it might contribute to the unusual experiences reported during psychomanteum sessions.

Before facing the mirror, participants were instructed to think about a deceased loved one for 15 minutes. They then sat before the mirror for 45 minutes while the researchers observed what happened during the session.

A special button allowed each participant to create a time stamp whenever an exceptional experience occurred. This gave researchers a way to compare the timing of reported encounters with the measurements being collected around them.

The monitoring included participants’ heart rates as well as environmental conditions. Researchers recorded electromagnetic fields, geomagnetic fluctuations, and temperature, with infrared camera recordings used during the psychomanteum sessions.

Afterward, participants rated the intensity of the apparitions they experienced. They also assessed whether the images felt real and whether the perceived figures seemed to occupy physical space rather than appearing only as visual imagery.

Those ratings were compared with the physiological and environmental monitoring data. Researchers also used surveys that measured participants’ creativity and the degree of synesthesia among those who had the trait.

The results did not show a difference in the degree of exceptional experiences between participants with synesthesia and those without it. The researchers described that result as unexpected, given their interest in whether mixed sensory processing might influence the encounters.

Creativity, however, produced a different pattern. Researchers found a correlation between a participant’s creativity and how real the visual imagery in the mirror appeared, a result that partially matched their expectations.

Environmental measurements also produced curious correlations. Among participants with synesthesia, geomagnetic fluctuations and electromagnetic fields appeared to influence perceptions of how much physical space an exceptional experience seemed to occupy.

The findings also showed some correlation with heart rate variability. Unlike the environmental associations observed among participants with synesthesia, the heart rate variability effect was not dependent on whether a participant had the neurological trait.

The results therefore offered no single, simple explanation for why people sometimes see more than their own reflection. Researchers said the findings suggest that interactions among individual differences, subjective experiences, and environmental factors could help explain why some people report these mirror encounters.

The study was published in the Journal of Anomalous Experience and Cognition. Its findings turned a ghostly mirror ritual into a monitored investigation of perception, personality, physiology, and the surrounding environment.