When Dr. Sterman examined the brainwaves of pilots doing simulated landing tasks, he found that the idling rhythms were suppressed in the parts of the brain that were being used at the time. He was able to fine-tune his findings by looking at these brainwaves in various control conditions, in which the pilots did only part of the task. To make a long story very short, Sterman concluded that in the back of the brain the processing of sensory inputs was associated with decreases in the idling rhythms from 11-15 Hz., while more complex thinking decreased idling rhythms from 8-12 Hz. The harder the task was, the more that these rhythms were suppressed.
In fact, Dr. Sterman was able to pick the best 6 pilots–those who were eventually selected as B2 bomber instructors–by measuring how well they suppressed the idling rhythms in the parietal lobe. This approach turned out to be more accurate, by itself, than all the other measures that the Air Force used in making this selection.
The Concentration and Recharge Cycle
Studies of pilots in the cockpit, as they actually flew their planes, showed that there was a short burst of idling rhythm between the individual tasks that they performed in the cockpit. The better pilots needed a shorter rest period before starting to focus again. We’ll call this recharging period a microbreak.
In fact, there is evidence that this kind of cycling between concentration and the microbreak is a basic way in which the brain functions. For example, there are studies that show that when we read, there is a brief idling rhythm in the visual cortex when we come to the end of a line and move on to the next.
Dr. Sterman performed a study which showed that these idling rhythms decrease right after a person is presented with a target to respond to, and then increase again when they finish processing their response to the stimulus. In the back of the brain, this idling rhythm was an 8-12 Hz. (alpha) burst that increased as they became more familiar with the task. As he looked at sites that were further forward in the brain, he saw that there was also an idling rhythm at 5 to 7 Hz.
There are also good, common sense reasons to believe that the brain is set up to cycle between concentrating and taking a recharging microbreak. Even the best of us cannot concentrate forever. We need our breaks. They are built in to our work and school day. The concept that each of us has an “attention span” that increases as we mature from child to adult, and then decreases in old age is a clear reflection of this well accepted concept. People who fail to regularly take these necessary microbreaks between tasks set themselves up for stress-related diseases because they accumulate the tension and anxiety from the continuous effort in their minds, brains, and bodies.
The most fundamental lesson of Peak Achievement Training is that we all need to cycle continuously between concentrating and taking a recharging microbreak in order to consistently be at our best without overtaxing our brains.
The Prefrontal Cortex and Executive Attention Network, New Learning, and the Cycle
The prefrontal cortex is also capable of alternating between concentration and idling. When things are familiar to us, it can idle, and let the other parts of the brain carry out their habitual ways of processing inputs, turning on and off in well established sequences. When they are unfamiliar, the prefrontal cortex and the Executive Attention Network get turned on. They have the role of bringing these new experiences into conscious awareness and figuring out how to process them by activating other centers of the brain. Dr. Sterman’s research indicated that the brainwaves of the frontal lobe, including the sites near the Executive Attention Network, also shows cycles when the individual is continually involved in detecting a series of targets. Right after a target is presented, the idling rhythm is suppressed, only to return in about half a second. After an event, the frontal cortex finishes its processing and goes into idle before the back of the brain does. The frontal lobe idling rhythm is primarily in the mid-theta range, between 5 to 7 Hz. Japanese researchers have detected this increased theta after doing other kinds of tasks, and called it the “frontal midline theta rhythm”.
By using the multiple displays of the Peak Achievement Trainer to examine the brainwaves of my students, I have been able to see their patterns as they concentrated and did a number of other things. At first, I looked for the relationship between concentration and the decrease in 5-7 Hz. rhythms at the midline site close to the hairline. I found that this was the clearest indicator of concentration that I had observed in my clinical experience. The Slow Bars display permitted me to look at the voltage output at each frequency from 1 to 40 Hz., and a special feature of the program permitted me to look more clearly at the higher frequencies, which are usually so low in output that they are hard to see. I saw clearly that as I and others concentrated, the voltage output decreased across the board, at all frequencies. This difference is shown in Figure 4, which is taken from the same record as Figure 1. The left side is concentration, while the right side is recharging.
Figure 4
Dr. Sterman had actually noticed the same thing, from about 5 to 15 Hz—all the frequencies that he measured—at virtually all the brainwave recording sites he tried. Technically, this is called “event related desynchronization”. In the frontal lobe, this suppression is followed by the return of the theta (5-7 Hz.) idling rhythm in about half a second, particularly after we see a target, rather than an unimportant control stimulus.
When people learn to suppress the idling rhythms, their attention problems clear up. Several large studies, now being submitted for publication, show that the suppression of theta and or alpha (depending on age and recording site) is largely responsible for the success of other brainwave training protocols in treating people with attention deficit disorder. Most all of the brainwave training protocols for treating attention deficit disorder have rewarded students for decreasing theta and/or alpha at central or frontal sites. These decreases were much more consistently related to successful treatment than the changes in higher frequencies that were also evaluated. Using a protocol that teaches the student to enhance beta may actually slow down training, because the feedback is less precise and more confusing than that provided by the Peak Achievement Trainer. It takes about ten sessions for a typical student to understand that type of brainwave biofeedback; almost everyone will understand this type of neurofeedback during the first session.
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