An article from the 8 May edition of the UK Financial Times by Dr Raj Persaud, consultant psychiatrist at the Maudsley Hospital, London.
In Dostoevsky's 'The Idiot', a character describes what it feels like to experience a particular kind of epileptic attack: "I have really touched God. He came into me, myself; yes, God exists, I cried. You all, healthy people can't imagine the happiness we epileptics feel during the second before our attack."
Dostoevsky himself suffered from epilepsy, a brain disorder characterised by random, rapid electric discharges in one area, which may spread to engulf the whole brain, sometimes producing hallucinations and widespread muscular convulsions. So his descriptions of epilepsy in 'The Idiot' are probably autobiographical.
His experience foreshadowed accumulating discoveries from modern neurology that establish a link between religion and particular brain areas - so much so that some neurologists are claiming finally to have found the location of God.
Epilepsy was known in ancient times as the sacred disease; modern research has found that about 25 per cent of those whose epilepsy involves the brain's temporal lobes (part of the brain on either side nearest the ears) develop a distinctive religious fervour.
Jeffrey Saver and John Rabin from the UCLA Neurologic Research Center argue that substantial numbers of founders of religions, prophets and other religious figures, display symptoms which suggest they suffered from epilepsy. Their list includes (the apostle) Paul, (the prophet) Mohammad and Joan of Arc, among 12 other religious figures of the past 2,000 years.
Vilayanur Ramachandran, professor and director of the Center for Brain and Cognition at the University of California, agrees there is a link between neurology and religious experience, and points out that many of his patients have spiritual experiences as part of their epileptic attacks. These include a feeling of divine presence and the sense that they are in direct communion with God. Everything around them is imbued with cosmic significance.
They may even say: "I finally understand what it is all about. This is the moment I've been waiting for all my life. Suddenly it all makes sense," or, "Finally I have insight into the true nature of the cosmos."
Does this syndrome, linking a form of epilipsy that originates from a particular brain area - the temporal lobes - and religion, imply our brains contain some sort of circuitry that is specific to religious experience? If there a God programmed in our heads?
In an attempt to answer these questions Ramachandran has attempted a series of scientific experiments directly on religion.
He compared emotional responses to various pictures and words. Sufferers from temporal lobe epilepsy had a heightened emotional response mainly to religious words and icons. Their responses to the other categories, including sexual words and images, which ordinarily evoke a powerful response, was diminished.
Ramachandran believes his and other experiments suggest human beings may have evolved specialised neural circuitry for the sole purpose of mediating religious experience, and temporal lobe epileptics lie at an extreme end of the spectrum of activity in this brain area.
After all, the human belief in the supernatural is so widespread in all societies all over the world that it is tempting to ask whether the propensity for such beliefs might have a biological basis. National surveys in the US, Britain and Australia find between 20 and 40 per cent of individuals report having had mystical experiences, and this figure rises to more than 60 per cent when in-depth interviews of randomly selected individuals are conducted.
Also, studies of twins raised apart suggest that 50 per cent of the extent of our religious interests and attitudes are determined by genes.
Moreover, Michael Persinger, a Canadian psychologist, recently found that one of the main differences between the 19 per cent of high school students who had religious experiences before their teens, and the rest, was the presence of a head injury or a blackout at least once during childhood.
When Persinger himself stimulated his own brain's temporal lobes using a transcranial magnetic stimulator, a helmet which shoots rapidly fluctuating and extremely powerful magnetic fields on to a small patch of the brain, so activating it, he experienced God for the first time in his life.
Feeling in the presence of God usually involves the strong emotional experience of awe, which is the kind of mood likely to be mediated by the temporal lobes.
But what about the other emotions involved in mystical sensations, such as the sense of connectedness with the rest of the universe?
Andrew Newberg and Eugene D'Aquili of the Nuclear Medicine Division at the University of Pennsylvania have been conducting brain-imaging experiments on highly proficient mediators in order to identify those other brain areas where activity is linked to religious experience. One of their most interesting findings was decreased activity in the posterior superior parietal lobule. Our sense of distinction between self and world may well lie in this brain area.
It is certainly described in the mystical literature of all the world's great religions as a state of ultimate unity. And when a person is in this state he or she loses all sense of discrete being, and even the difference between self and others is obliterated.
Such experiences are often described as a perfect union with God, and would appear to be mediated by the posterior superior temporal lobule, which is what helps us diffentiate between self and non-self. So altered activity in this area might be linked with a sense of unity with the world.
A decreased sense of awareness of the boundaries between the self and the external world could lead to a sense of oneness with others, thereby generating a sense of community and cohesiveness. This could explain why religious sentiment could be of positive benefit for the survival of tribes. This could also explain why natural selection favoured the evolution of a religious centre in the brain.
But Newberg and D'Aquili have an even more parsimonious neurological explanation for God. They point out that one natural function of our brains is constantly to infer the causes of events we witness. But what happens when no cause is discernible?
Newberg and D'Aquili postulate that the brain invokes gods, powers, spirits or some similar causal agent. When we find no discernible rules we can use to our advantage, we construct myths to help orientate ourselves within that disquieting universe.
But even if the final location of God is in the temporal and parietal lobes of the brain, this might not be a final victory for atheists. Finding the existence of a neural structure which sustains religious experience could simply be evidence that a higher power so contructed humans as to possess the capacity to experience the divine.
Given that we are now almost certain such a structure exists and it is probably inadvertently removed as part of the brain surgery often carried out to cure intractable epileptics, what happens, asks Ramanchandran, to patients' spiritual leanings when we remove these parts of their temporal lobes?
Have we performed a Godectomy?