Well during and since the MK Ultra experiments it was proven that it's possible to transmit radio waves at the same frequency as the human nervous system using Ll + Lp waves or some shit like that I can't remember the exact frequency.
This enables the person controlling the transmission to project voices or thoughts directly into the victims brain whilst at the same time blocking out the victims perception of "hearing themselves think" eradicating any rational analysis of the projected thoughts.
It seems on face value that they've found a simple frequency that stimulates the plants stomata, it's very plausible.