Mystical experiences may stem from the brain letting go of inhibitions, opening a "door of perception," researchers found.

During mystical experiences, people feel connected to a higher power and often describe gaining hidden knowledge or having revelatory insights. Although people around the world have reported mystical experiences, ranging from near-death experiences to ecstatic visions to meditative trances, these visions remain shrouded in mystery, with little neuroscience research to explain their underpinnings in the brain.

Previous research suggested two broad camps of theories to explain the brain origins of mystical experiences, called "push" and "pull" theories, respectively.

"Push theories argue that activation of a single 'God spot' causes mystical beliefs, suggesting that injuries to these spots would reduce mysticism," study co-author Joseph Bulbulia, a religious studies researcher at Victoria University of Wellington in New Zealand, said in a statement. "In contrast, pull theories argue that the suppression of our inhibitory functions opens up the brain to mystical experiences. It is a hotly disputed topic, and we set out to clarify the debate."

Now, Grafman and his colleagues have evidence to suggest that pull theories may help to explain mystical experiences.

In their new study, the scientists analyzed 116 Vietnam War veterans who experienced brain damage and had mystical experiences, and compared them with 32 combat veterans without brain injuries or neurological disorders. All of the veterans took psychological tests before and after their conflicts.

"Often, the veterans said they heard the word of God, or had visions of their family," Grafman said. "Those are common mystical experiences."

The researchers also conducted interviews of the patients using the Mysticism Scale, a well-established test for analyzing reports of mystical experiences. The scale asks respondents about feelings of unity and joy, as well as a sense of transcending time and space. The scientists also carried out high-resolution computed tomography (CT) brain scans of all of the Vietnam veterans participating in the study.

The researchers found that damage to the frontal and temporal lobes was linked with greater mystical experiences. Previous research found that the frontal lobes, located near the forehead, are linked to movement, problem solving, memory, language and judgment, among other functions. The temporal lobes, located near the bottom of the brain, are linked to the senses, language and memory.

Further investigation revealed that damage to a specific area of the brain known as the dorsolateral prefrontal cortex was linked to markedly increased mysticism. Previous research found that this brain region, located in the frontal lobes, is key to imposing inhibitions.

The scientists detailed their findings in the Jan. 8 issue of the journal Neuropsychologia.