The Amazing Backstory of Neurofeedback
Updated: May 23, 2019
For a field that seems very recent, its origins go back 70 years. Then, Barry Sterman, a young researcher at UCLA wanted to find out whether he could train an animal to control its brainwaves using a method known as operation conditioning. As you may remember from Psychology 101, operant conditioning happens when you give a reward after a behavior happens (and make sure not to give a reward when it doesn’t happen). And to complicate matters, Sterman worked with cats, which as subjects, are probably much less cooperative than dogs. In any case, Sterman chose to focus on a brainwave called a “sensory motor rhythm” (SMR). This is a commonly occurring brainwave which is associated with a relaxed but alert focus. It’s what a cat produces when it is still and watching something interesting. It is a “ready for action” state.
In his experiment, Sterman dribbled milk into the cat’s mouth when there were bursts of SMR and withheld the milk when they were not producing SMR. With this basic operant conditioning Sterman demonstrated it was possible to train cats to produce more SMR.
Just to make sure, he then rewarded the cats when they weren’t making SMR and withheld the milk when they did produce SMR brainwaves. Switch the conditions and the amount of SMR went down. Point made, case closed. In truth, the only point to the research was to find out if it was possible to train a cat to control its brainwaves. Sterman published his studies and the world took little notice. Such is the life of a basic science researcher.
Not long after the cat study was finished, NASA put out a grant to solve an unexpected problem. Their astronauts were hallucinating during space flight. It was suspected that leaks in the rocket fuel were triggering the hallucinations and NASA wanted to know if there was a safe level of exposure to the chemical in the rocket fuel. Sterman got the grant to study this question. Not only was he qualified to do this type of study, but it probably helped fund his lab.
Sterman’s experimental design was to expose his lab cats to increasing levels of the rocket chemical and to observe the effect. It was predicted that as the exposure got higher, symptoms of seizure-like behavior would start to show. But the results were confusing. For some of the cats, the response was what was expected, more chemical exposure made the cats progressively sicker.
Here’s where it gets interesting. Some of the cats didn’t get sicker with the higher exposure. Then it was noticed that it was the cats who had participated in the previous experiment, the one where they learned to control their brainwaves, that were now resistant to chemically induced seizures.
Sterman’s next step was to see if what applied to cats might work with humans. Rather than induce seizures, he investigated whether humans who already had intractable seizures could be cured if they undertook the same training that the cats got (minus the milk). And indeed, they could. It wasn’t quick, something over 200 hundred sessions, but it worked. Sterman published all of this in peer-reviewed medical journals. If it didn’t change the practice of neurology, it may be because we have a preference for medication. And 200 sessions is a lot to ask. But the field was born.
It’s worth pointing out how Sterman’s work totally dispelled the possibility of neurofeedback being a placebo. In his first study, he had no thought that the operant conditioning would have any effect other than to alter the amount of SMR. And in discovery of the effect of training on seizure resistance was a serendipitous finding. It should be added that cats are not especially inclined to “please” a researcher, especially when he has locked them in a cage. And finally, Sterman undertook all of the experimental controls to rule out placebo by doing reversal designs and yoked-controls in his studies with epilepsy.
It might be added that some of that research probably wouldn’t have passed human subjects protection regulations today. However, no cats or humans were harmed in his work. In fact, Sterman’s subjects reported that not only were the seizures improved, but so was their memory, focus and mood. Others took notice of those reports and this led neurofeedback shifting from a focus on seizures and medical concerns and more towards mental health concerns including ADD/ADHD, anxiety and addictions. The latter is the focus of next fascinating discovery.
If Sterman was motivated by pure scientific curiosity, Eugene Penniston, a psychologist at the VA was driven by a deep personal desire to help patients, who like his brother, suffered from alcoholism. Sometime in the 1980’s Penniston had visited the Menninger Foundation, a respected psychiatric institute in Topeka, Kansas where they were studying the dimensions of human experience. Some of their work involved a form of biofeedback call “Alpha/Theta training” because of the brainwaves being trained. Alpha waves are in the 8 to 13 Hz range and is associated with being relaxed. Theta waves, are in the 3 to 8 Hz range and are associated with a detachment from the external world and a shift to internal, free-associative state of thoughts, images and sensations. There were some indications that inducing this state in someone might be useful in treating alcoholism. So Penniston decided to test this approach in the alcohol treatment ward of the VA hospital in Colorado where he worked.
Penniston’s treatment protocol included a few sessions of relaxation training and then 30 sessions of Alpha/Theta brainwave biofeedback. Just prior to each session, Penniston helped his subjects visualize how they might resist the temptation to drink and to imagine a positive life without drinking. He compared the results of 10 subjects who did the Alpha/Theta training with 10 others who received the usual in-patient program. All of his subjects had at least 4 failures in prior treatment with the VA. It was also the case that as combat vets, all of the men had experienced combat trauma.
The results were stunning. Eight of those who got the Alpha/Theta training remained sober after release from the program. The remaining two, having dismissed the training as a meaningless exercise, soon found out that they had lost their tolerance for alcohol and became abstinent as well. All the controls were re-admitted to treatment within eighteen months. The experimental subjects were followed for more than eight years. All remained sober.
As part of his study, Penniston did something particularly clever; he collected blood from all the subjects to measure their cortisol levels, an objective measure of stress. Interestingly, upon admission all of the subjects showed low levels of stress. But as time passed, the control subjects started showing increasing levels of cortisol. Absent their drinking, they were getting highly stressed. Alcohol was a stress manager.
On the other hand, the cortisol levels of the vets in the Alpha/Theta training group remained low. It seems that undergoing the brainwave training both permitted to remain in more comfortable during treatment and to have induced some sort of psychological changes that carried well past discharge. The application of neurofeedback to substance abuse and trauma was established.
The field of neurofeedback continued to advance, extending to more and more conditions. Advances in brain imaging and the use of various forms of brain mapping to decide where to place the electrodes and what brainwave frequencies to reward or inhibit became the focus for much of the field. However, other practitioners continued to treat by matching client concerns to known treatment protocols. For example, training using SMR brainwaves, the same procedure Sterman used was the basis for much of the published literature on treating ADHD.
The third time where the neurofeedback took a surprising direction was with the work of Susan and Siegfried Othmer. Susan, a former doctoral student in neurophysiology and her husband Siegfried, an experimental physicist got into the field impressed by the impact neurofeedback had on their son’s epilepsy.
Initially the Othmers followed the path set by Sterman, working the SMR and beta range (15-18 Hz) of brainwaves. However, as the software became more flexible, they discovered that rather than training in the usual brainwave frequencies, they got better results when they “optimized” the training frequency to the client. Optimization typically meant going to frequencies below SMR. It is important to understand that the way brainwave frequencies work, the lower frequencies are associated with sleep while higher frequencies with alertness.
And here is when it gets almost spooky. What the Othmers started finding was that the lower and lower the training frequency, the better and faster their results, especially with more distressed or disturbed clients. Contrary to everyone’s expectations, training clients in this very low range didn’t put them to sleep, it made them very relaxed while still remaining alert. It was like Columbus; sailing into the unknown he didn’t fall off the edge. He discovered a whole new world. And so did they.
Today much of the Othmer’s work involves working with brainwaves in the infra low frequency (ILF) range where one oscillation can occur every hour to up to several days. Training in these frequency bands required significant advances in the underlying technology but the results in terms of impact on clients has been noticeable. Curiously, it moves neurofeedback training into the realm of the brain’s Default Mode Network. But that is a story for another day.