Former CIA whistleblower Dr. Robert Duncan describes neuroweapons and some of their functions. Around the 30 min mark of the video Dr. Duncan describes direct neuromodulation methods including neurotransmitter dumps and ionic channel protein conformational changes. 

He states at 33:05 in the video "We can use a cold virus viral infection to all of humanity and make them susceptible to whatever frequency we want their brain to be susceptible to."

https://www.neuroweaponforensics.com/neuroweapons