Psychology Today May/June 1998

Page 2

Neurofeedback is part hero and part orphan these days. Despite some powerful research that testifies to its impact, it is only peripherally concerned with what has become the hot top- ic in neuroscience: neurotransmitters. Far less fashionable than Prozac or Paxil, neurofeedback seems to work by intervening in the realm of frequency. Frequency is the rate at which electrical charges move through brain cells. The human brain is measured by four basic frequency ranges. In delta, the sleep state, signals are moving through clusters of neurons very slowly, just 4 cycles per second, or hertz (Hz).

Just above that is theta, around 4 to 8 Hz, a deeply relaxed state. Next is alpha, a slightly less relaxed state, at 8 to 13 Hz. The most rapid brain waves are beta, and they reflect normal waking consciousness. How- ever, there's a range of beta, from low beta, which is a re- laxed but alert state of 12 to 15 Hz, to mid-range beta, around 15 to 19 Hz, up to an excited, hyper state of high-beta-as high as 35 Hz.

Even though our measures of frequency (through EEG) are relatively crude, they seem to provide a window into ex- citability within the brain. Researchers believe that problems crop up when the operating speed of someone's brain is either too low (underarousal) or too high (overarousal). As Othmer puts it, "some people can't find the gas pedal while some people can't take their foot off it." There is speculation that arousal levels may be a major component in a whole host of disorders and their prevalence may be the key to neurofeed- back's sometimes miraculous effect. The goal? To stabilize the brain, to render it more robust, so that it does not tip easily into overarousal or underarousal.

Viewing the human mind this way, through the prism of neurofeedback, harkens back to a theory of arousal that was popular in the 1950s. This approach essentially cuts across the spectrum of psychological diagnostic categories with just two physiological measures: stability and arousal. According to this theory, optimal idling speed for the human brain is about 14 Hz. If the brain's major activity is a speed lower than that-8 to 13 Hz-a person can feel tired and might seek stimulation through coffee or stimulating behavior. They might suffer from depression, ADD, and mild dissociative disorder. Overarousal, on the other hand, means a person has trouble unwinding and might seek out several glasses of wine at the end of the day to modulate their arousal level. Or. they might need Valiurn. Anxiety attacks, hypervigilance, stress, and obsessive behavior are all symptoms of overarousal.

Researchers believe that
neurofeedback modulates
levels of arousal in the brain-
which may alleviate the
symptoms of an astonishing
range of disorders.

HOOKED UP to Happiness

Neurofeedback sessions are surprisingly fun and simple: they're like playing computer games where every move is made by the mind. The technology utilized in neurofeedback, how- ever, is fairly sophisticated, and unit prices can run from $3,000 to $9,000. Brain waves must be mapped and analyzed for deviations from the norm. If there is, for instance, too much theta-which often occurs in brain trauma, as well as in depression-and not enough beta, the practitioner will set parameters for a slightly healthier brain wave map.

A session may consist of playing some kind of computer game-in which a smiling Pacman gobbles up enemy blobs or a balloon tries to float up to the sky-while the patient's brain waves are contin- uously monitored.

Each time the brain waves find their way into the optimal state set by the practitioner, the patient is rewarded with positive feed- back: Pacman eats his enemy or a pleasant tone sounds. After anywhere from five to fifty sessions, the brain seems able to find the optimal state on its own. One of the ingenious aspects of neurofeedback is that it is perfectly tailored to each individual. Training is always set to be challenging and exciting but not too difficult, so that patients can move slowly and steadily into their optimal brain states.

BIOFEEDBACK'S Bold Beginnings

In the 1960s, neurofeedback was a revolutionary way to look at the mind and its capabilities, and it coincided with other, more dubiously regarded revolutions. Neurofeed- back was adopted by people interested in mind expansion, often in the forms of LSD and meditation, and its association with Eastern mystics and parapsychology earned it a crackpot reputation with the mainstream scientific com- munity. But when I actually went and looked at the early re- search, I was astonished at some of the remarkable studies.

One of the crucial pioneers of neurofeedback was Barry Sterman, Ph.D., professor of neurobiology and biobehavioral psychiatry at the UCLA School of Medicine, who was the first to experiment with a kind of beta wave called sensory motor rhythm (SMR), in the 12 to 15 Hz range of beta, and was able to actually treat epilepsy.

Sterman's original work in the 1970s was on cats. Using implants and EEG equipment in a study funded by the National Institutes of Health, he found that cats could be trained to control their brain waves. He then discovered that when he exposed those trained cats to toxic vapors that usually induce epileptic seizures, they had far fewer seizures than untrained cats. The experiment was replicated with monkeys. In both cases deep probes showed that the training produced physio- logical changes in the brain's neurons.

Moving on to humans with refractory epilep- sy-the most severe kind-Sterman achieved a 60% reduction of seizures in 60% of his patients. Numerous other experiments at more than a dozen other institutions have demonstrated even higher success rates, and the treatment of epilepsy is the most established of the protocols for neurofeedback. Sterman, who is now research director at EEG Spectrum, has theorized that training may activate healthy adjacent neurons to take the place of damaged ones. We are still a long way from a real understanding of why neurofeedback does what it seems to, but Sterman maintains that "if the neural substrate is intact, the neurons can be trained."

One of Stermans researchers, Joel Lubar, Ph.D., of the University of Tennessee at Knoxville, took their work even further and in a different direction. He had noticed that hyperactivity decreased in patients treated for epilepsy and, based on this, created the protocol now used for treatment of ADD.

 

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Psychology Today May/June 1998