https://schumannresonance.today/ (article)
Seems that Russia (during U.S.S.R., and still) is most active with Schumann Resonance research.
Consider the difference between the highly attentive state of 40-80Hz and 2GHz-10GHz for example.
Consider that Dream state is .5 - 4 Hz (physical renewal) and 4Hz-8Hz . . . light sleep.
So much of what has been publishes is sort of mix of science and woo woo/spirituality.
However, there is more "mechanical" (if we can label quantum energy as mechanical) scientific research being done that does not necessarily address effects on body and mind.