God on the Brain - programme summary

Rudi Affolter and Gwen Tighe have both experienced strong religious visions. He is an atheist; she a Christian. He thought he had died; she thought she had given birth to Jesus. Both have temporal lobe epilepsy.

Like other forms of epilepsy, the condition causes fitting but it is also associated with religious hallucinations. Research into why people like Rudi and Gwen saw what they did has opened up a whole field of brain science: neurotheology.

The connection between the temporal lobes of the brain and religious feeling has led one Canadian scientist to try stimulating them. (They are near your ears.) 80% of Dr Michael Persinger's experimental subjects report that an artificial magnetic field focused on those brain areas gives them a feeling of 'not being alone'. Some of them describe it as a religious sensation.

"...a high probability [Ellen White] had temporal lobe epilepsy"

His work raises the prospect that we are programmed to believe in god, that faith is a mental ability humans have developed or been given. And temporal lobe epilepsy (TLE) could help unlock the mystery.

Religious leaders

History is full of charismatic religious figures. Could any of them have been epileptics? The visions seen by Bible characters like Moses or Saint Paul are consistent with Rudi's and Gwen's, but there is no way to diagnose TLE in people who lived so long ago.

There are, though, more recent examples, like one of the founders of the Seventh Day Adventist Movement, Ellen White. Born in 1827, she suffered a brain injury aged 9 that totally changed her personality. She also began to have powerful religious visions.

Representatives of the Movement doubt that Ellen White suffered from TLE, saying her injury and visions are inconsistent with the condition, but neurologist Gregory Holmes believes this explains her condition.

"These patients are more prone to religious belief"

Better than sex

The first clinical evidence to link the temporal lobes with religious sensations came from monitoring how TLE patients responded to sets of words. In an experiment where people were shown either neutral words (table), erotic words (sex) or religious words (god), the control group was most excited by the sexually loaded words. This was picked up as a sweat response on the skin. People with temporal lobe epilepsy did not share this apparent sense of priorities. For them, religious words generated the greatest reaction. Sexual words were less exciting than neutral ones.

Make believe

If the abnormal brain activity of TLE patients alters their response to religious concepts, could altering brain patterns artificially do the same for people with no such medical condition? This is the question that Michael Persinger set out to explore, using a wired-up helmet designed to concentrate magnetic fields on the temporal lobes of the wearer.

"Feeling something beyond yourself, bigger in space and time, can be stimulated"

His subjects were not told the precise purpose of the test; just that the experiment looked into relaxation. 80% of participants reported feeling something when the magnetic fields were applied. Persinger calls one of the common sensations a 'sensed presence', as if someone else is in the room with you, when there is none.

Horizon introduced Dr Persinger to one of Britain's most renowned atheists, Prof Richard Dawkins. He agreed to try his techniques on Dawkins to see if he could give him a moment of religious feeling. During a session that lasted 40 minutes, Dawkins found that the magnetic fields around his temporal lobes affected his breathing and his limbs. He did not find god.

"A talent for religion... some people have and other people don't"

Persinger was not disheartened by Dawkins' immunity to the helmet's magnetic powers. He believes that the sensitivity of our temporal lobes to magnetism varies from person to person. People with TLE may be especially sensitive to magnetic fields; Prof Dawkins is well below average, it seems. It's a concept that clerics like Bishop Stephen Sykes give some credence as well: could there be such a thing as a talent for religion?

Brain imaging

Sykes does, though, see a great difference between a 'sensed presence' and a genuine religious experience. Scientists like Andrew Newberg want to see just what does happen during moments of faith. He worked with Buddhist, Michael Baime, to study the brain during meditation. By injecting radioactive tracers into Michael's bloodstream as he reached the height of a meditative trance, Newberg could use a brain scanner to image the brain at a religious climax.

"People meditating describe a loss of sense of self"

The bloodflow patterns showed that the temporal lobes were certainly involved but also that the brain's parietal lobes appeared almost completely to shut down. The parietal lobes give us our sense of time and place. Without them, we may lose our sense of self. Adherants to many of the world's faiths regard a sense of personal insignificance and oneness with a deity as something to strive for. Newberg's work suggests a neurological basis for what religion tries to generate.

Religious evolution

If brain function offers insight into how we experience religion, does it say anything about why we do? There is evidence that people with religious faith have longer, healthier lives. This hints at a survival benefit for religious people. Could we have evolved religious belief?

Prof Dawkins (who subscribes to evolution to explain human development) thinks there could be an evolutionary advantage, not to believing in god, but to having a brain with the capacity to believe in god. That such faith exists is a by-product of enhanced intelligence. Prof Ramachandran denies that finding out how the brain reacts to religion negates the value of belief. He feels that brain circuitry like that Persinger and Newberg have identified, could amount to an antenna to make us receptive to god. Bishop Sykes meanwhile, thinks religion has nothing to fear from this neuroscience. Science is about seeking to explain the world around us. For him at least, it can co-exist with faith.