
The study involved 30 adults - 15 committed Christians and 15 nonbelievers - who underwent three functional MRI (fMRI) scans while evaluating religious and nonreligious statements as "true" or "false." The statements were designed to produce near perfect agreement between the two groups during nonreligious trials (e.g., "Eagles really exist") and near perfect disagreement during religious trials (e.g., "Angels really exist"). Contrasting belief and disbelief yielded increased activity in the ventromedial prefrontal cortex (VMPFC), an area of the brain thought to be involved in reward and in judgments of self-relevance. "This region showed greater activity whether subjects believed statements about God, the Virgin Birth, etc., or statements about ordinary facts," the authors said.
The case for belief being content-independent was further bolstered by the fact that while the trial statements accepted by religious believers were rejected by nonbelievers, and vice versa, the brains of both showed the same pattern of activity for belief and disbelief. A comparison of all religious with all nonreligious statements suggested that religious thinking is more associated with brain regions that govern emotion, self-representation and cognitive conflict in both believers and nonbelievers, while thinking about ordinary facts is more reliant upon memory retrieval networks. Activity in the brain's anterior cingulate cortex, an area associated with cognitive conflict and uncertainty, suggested that both believers and nonbelievers experienced greater uncertainty when evaluating religious statements.
The study raises the possibility that the differences between belief and disbelief may one day be reliably distinguished by neuroimaging techniques. "Despite vast differences in the underlying processing responsible for religious and nonreligious modes of thought," the authors write, "the distinction between believing and disbelieving a proposition appears to transcend content. These results may have many areas of application - ranging from the neuropsychology of religion, to the use of 'belief-detection' as a surrogate for 'lie-detection,' to understanding how the practice of science itself, and truth-claims generally, emerge from the biology of the human brain."
Harris is the author of two New York Times best-sellers, The End of Faith and Letter to a Christian Nation which have been published in more than 15 languages, and is the co-founder and CEO of The Reason Project. His writing has appeared in Newsweek, the New York Times, the Los Angeles Times, the Times of London, the Boston Globe, the Atlantic and many other journals. Other authors on the study included Cohen, Susan Bookheimer and Marco Iacoboni of UCLA; and Ashley Curiel of Pepperdine University. The authors report no conflict of interest.