These researchers don’t know what they are doing. I’m sure the rat brain wave frequencies do not go anywhere near the prefrontal virtex analytical thinking neuronal fisring rate of 30 Hz.
Thus, with rats there would be minimal influence on brain function at 40 Hz.
When the human brain moves from 30 Hz to 40 Hz it goes into a higher dream state of lucid dreaming.
Above 40 Hz is moving into the gamna frequency which can cause psychotic breaks in patients.
If a person is balanced and purified enough in their consciousness, 40 Hz can lift them up. If not, it will shake them up and potentially cause damage.
I’ve been researching brain wave frequencies and Transmagnetic Cranial Stimulation techniques for 20+ years.
There are many variables they are not considering. Phase changes, voltage, amperage, direction of flow, amplitude within frequency, masculine vs feminine consciousness.....