Peter H. Charlton, Andrey Parfenov, Ildar Rakhmatulin, YouTube video makers & brain scan study participators who test their specific devices with brain scanners to sell them on YouTube with scientific papers which proof their effect?

Last Updated on March 26, 2024 by pg@petergamma.org

But there is no need to test all kind of devices with a brain scanner:

one method is enough.