The brainwave research has a long history and it was already discussed around 1950s that there is a possibility to affect the brain from the outside electromagnetic wave. Jo Kamiya established EEG and the biofeedback as an academic study in 1960s, and thereafter it is a fact that the external wave has an influence on the brain.
These studies were quite active in 1970s, though declined in 1980s. The reason behind this decline was not sure, though there is one apparent explanation that the first generation researchers were retired to end their accomplishment around that time. It is often seen in the academic field that some research subject is focused on attracting many researchers and money, which yields a breakthrough result, though it is diminishing over the time when assumed there is no progress in the future.
However, the EEG and brainwave have still been actively researched to achieve to the level where the brain is controlled by the radiowave, hence the academic break-through cannot have been extinct in 1970s. It implies there should be another explanation why the research accomplishment was diminished in those days.
There is one of the issues emerged in its history: a criticism that the brainwave is a pseudo-science. Historically, it is assumed to be an alchemical science that the brain is affected by the external electromagnetic wave.
It is partially because of its limitation as a science. For example, the frequency of depression can be researched through try and error, where the subject is irradiated by various frequency patterns to confirm finally that the brain is suffered from the depression. It can be diagnosed as such just with the brainwave pattern if your brain shows the specific wave of depression, though it is quite hard to confirm that you finally suffer from it, as it is difficult to quantify the human emotion.
Also, it is more troublesome to make the subject depressed through the experiment. This research is more crucial when it is extended to cause the subject a stroke, which is almost unacceptable as it is lethal. It is nothing more than the illegal human experimentation.
It is a fact that the electromagnetic wave can cause a stroke, which was found through the treatment, not through the human experimentation. However, it is necessary to test at the living brain for a further understanding of its function. This test can be more progressed when the research tries and errors from various viewpoints, how to cause the stroke. That is one of the legitimate ways of the science, but it cannot be accepted for this study, legally and ethically.
The external electromagnetic wave is an input to affect the brainwave as an output in this case. The stimulus is given to the subject yielding the result, though the study is an activity to clarify a black box of this causality. The empirical result is sometimes not a study, even though it is more practical to know what kind of input yields a certain result. In this case, what kind of frequency pattern creates a change of the brainwave, which is also transferred to the specific behavior in the end.
For example, the hand is reacted to the electricity irradiated to the certain brain address. This was already found academically, which is kind of big breakthrough, as we can near to understand how the brain works. However, the certain electromagnetic wave can control the hand to go up and down, which does not explain how the wave affects the brain to move the hand. If this is not explained, it might not meet the criteria of the science. This means the EEG and biofeedback has an aspect to be denounced as a pseudo-science. However, this brainwave is more practical than the brain address.
To tell the truth, it is more likely to be labeled as the pseudo, which is more suitable for the people who would like to use this research outcome. It is more precise to say that there was a huge break-through in 1980s as well, which was nearly impossible to publish partially due to the nature of its experiment or partially due to a prohibition to report. As a result, the treatment of biofeedback was left in the public eyes and another progress has been concealed for a long time.
These researches are highly likely funded by the government subsidy, hence they cannot publish them once the field is sealed as classified. Even though there are many people realizing the brain is controlled by the wave, but its exposure is categorized as a criminal activity, hence nobody talks about it. That is the main reason why the research accomplishment was declined from 1980s.