Neuroscientific Notes: Is there intelligent life on earth?

COCKTAIL PARTY conversations can be strenuous for a brain scientist. Questions like "Is it true that we only use 10 per cent of our brain?" leave the poor fellow nonplussed.

The stoneless olive spiralling in his stirred dry Martini, the academic puts on a smile and utters that in fact this is not the case, that there is no evidence for such a claim, that all we know about the brain indicates that this assertion is sheer nonsense. "Well" - urges the interlocutor - "that's what you believe, but I have read it in an interesting self-help book entitled Synapses: auntie's thighs and the Darwinian ecosystem." The scientist brings the conversation to a hasty conclusion, and beats a strategic retreat, pretending to be preoccupied with lofty thoughts, in his heart cursing the weakness of the null-hypothesis argument: how can we convince somebody that something simply is not as they think?

The idea that we only use 10 per cent of our brain is a myth. If it were true, nine out of ten patients with a stroke would show no symptoms. Unfortunately this is not the case. A number of other misconceptions about brain mechanisms are taken for granted even by well- read, educated people. These include the belief that people can be resuscitated from a coma by listening to their favourite songs; the idea that the right hemisphere is where creativity lives; that magic pills preventing ageing do exist; that we can be trained to capitalise on non-physical energies of the brain; that one can retrieve pre-adolescent sexual abuse by means of hypnosis or learn a language by listening to tapes while sleeping; or even the possibility of cloning the human brain.

The recent debate about the rights and wrongs of human cloning has led us to the alarming suggestion that it could be possible to reproduce evil people: could Hitler live again? Could we duplicate somebody like the football superstar Eric Cantona? Studies of identical twins, who are natural clones, do not support the myth that they also have identical brains, and by implication, identical minds. If two identical foetuses look once in opposite directions, their brains will be different. Indeed, clones can never be exact replicas of each other (as we duly learned from movies like Multiplicity).

Myths are beautiful fables devised to account for all the mysteries of life and death. Few people now would maintain a supernatural cause of infections, though only little more than a century ago, before the discovery that bacteria caused diseases, this was the common view. In the dearth of understanding of the mechanisms of the mind and the brain, and the effects of their diseases, we still tackle their mysteries by aping early man: invoking divine intervention or taking shelter in simplistic dogmas.

Popular books sustaining such myths overflow from the shelves. We live in a very credulous world. Any right-minded alien visiting us would wonder whether there is intelligent life on earth. As with most domains of human knowledge, the various disciplines loosely lumped together as neurosciences are not exempt from personal beliefs, prejudices, faith, hopes, hunches, and ultimately myths.

The neuroscience and psychology literature is the principal myth-maker. Nevertheless, the scientific tradition has embedded rules which decrease the chance of blunders existing for very long. The acceptance of these rules in accruing knowledge marks the difference between science and beliefs, between what we do know about the mind and the brain and what we think we know about them. Perhaps more important, accepting these rules allows us to admit what we do not yet know.

Understanding how the brain functions through the methods of science can be a creative endeavour; unsubstantiated beliefs are tedious.

Sergio Della Sala is the editor of `Mind Myths: exploring popular assumptions about the mind and the brain' (Wiley, pounds 19.99)