The Nobel Prize is one of the world's top awards. Usually there is no doubt about the intellectual stature of the winners, although the recipients of the Peace Prize sometimes make me wonder. However, my candidate for most improbable winner derives from a different field. In 1949, the Portuguese neurologist, Antonio Egas Moniz, was awarded the Nobel Prize for Physiology and Medicine. His achievement? He pioneered frontal lobotomies as a medical treatment.

A frontal lobotomy is a rather simple operation. A sharp knife is inserted into the frontal lobes of your brain (roughly speaking, those are the parts you use for thinking) and wiggled around in there. Occasionally parts of the brain are also removed. The treatment was recommended at one time for depression, violence, schizophrenia, and even alcoholism. Quite often it worked, since the operation reduced the patient to a vegetable incapable of either emotion or action. Having your brain stirred around with an eggbeater, even a very small one, tends to have that effect. As a leading promoter and performer of lobotomies, Walter Freeman, chillingly remarked, "lobotomized patients make rather good citizens."

Frontal lobotomies are now banned. I view the whole idea with a peculiar horror, agreeing with the Country and Western song, "I'd rather have a bottle in front of me than a frontal lobotomy." Our brains represent the "real" us far more than any other part of the body, and Alzheimer's disease, with the body living on while the owner is unaware of it, is in a literal sense a living death.

Diseases of the brain, however, are all too common, and to understand and treat such ailments we must have methods of exploring brain function. Lobotomies are not the answer. That's like curing an ingrowing toenail by cutting off your leg. The brain is a delicate and sophisticated organ, and to explore it we need equally delicate and sophisticated techniques.

One problem is that the brain is well protected, encased in a strong bony shell with several protective interior layers of tough membranes known as "meninges." Direct access occurs only when there is accident or brain disease, which are by definition extraordinary circumstances. How can we learn what is going on in a normal working brain?

The key understanding is that brain activity is always accompanied by electrical activity. Each time a neuron fires, a minute current flows. If we can map the electrical activity that goes on when a person takes a specific action, we can also learn which part of the brain is involved in that activity.

Unfortunately, the brain is as well protected against electrical interference as it is against physical interference. Electroconvulsive therapy is still used to treat severe depression, but that requires near-electrocution, whamming the brain with such a powerful surge of current that amnesia for weeks or months is a common side effect. That is nothing like the delicate diagnostic tool that we would like.

We need to eavesdrop on brain activity in a non-invasive way. One way of doing so is with the use of an EEG, or electroencephalograph, which "listens in" on the patterns of electrical waves that our brain generates while sleeping or waking. The EEG has been the principal tool for understanding modes of sleep, but it does not let us tie thought processes to specific brain locations. That can be done, at least partially, through the use of another gadget known as a SQUID, or Superconducting Quantum Interference Device. This is able, from outside the head, to measure the extremely low magnetic fields associated with the minute currents that flow in the brain. It does so without interfering with thought processes.

EEGs, SQUIDs, and other machines such as magnetic resonance imagers (MRIs) and CAT scanners offer what we might call passive approaches. We watch and listen to electric currents and magnetic fields, then seek to correlate what we hear and see with what someone is doing. These correlations are sometimes tricky, because we are never sure if there are other reasons why someone rubs his eye, stammers, blushes, or scratches her knee.

What about a more active approach? A recent one, known as transcranial magnetic stimulation, or TMS, applies a magnetic field to some small chosen region of the brain. It operates from outside the head, and one of the nice things about a magnetic field is that it passes easily through the skull and into the depths of the brain without doing damage or producing lasting effects. Volunteers who have taken part in TMS experiments report a variety of physical and mental reactions. Sometimes the magnetic field induces an obvious physical response - a toe or finger may jerk, or a lip twitch. Sometimes the field, applied to a particular part of the brain, temporarily "switches off" a brain function. For example, a blind person's ability to read Braille can be reduced when the magnetic field is applied to the part of the brain known as the visual cortex.

More and more, medical science provides non-invasive testing and less invasive operation. Today, removal of a gall bladder usually means a day in the hospital and a near-invisible scar. Replacement of an eye lens is an outpatient procedure; joint replacement is routine and commonplace. Our understanding of and ability to repair every organ in the body leaps ahead every year - with one big exception. The brain remains the final frontier, its operation poorly understood, its functions poorly mapped.

That situation is overdue for a change. We have a whole alphabet of existing tools - MRI, PET, CAT, EEG, TMS - whose use in brain research is just beginning. Refinement of this array, plus new tools provided as electronic devices shrink toward cell-size levels and can be implanted within the brain itself, will lead to a new level of understanding. With that understanding will come treatments and then cures for everything from Alzheimer's to Parkinson's to epilepsy to suicidal depression.

As always, we have to ask: when? My belief is that if 2000-2010 will be, as many scientists proclaim, the decade of the human genome, then 2010-2020 will be the decade of the human brain.

"Borderlands of Science" is syndicated by: