A SECRET NOFORM* document from 17 february 1998 was declassified under the freedom of information ACT in december 2006. It is self described as (emphasis mine):

“This addendum to the Nonlethal Technologies*Worldwide (NGIC-I 147-101-98) study addresses in summary, some of the most often asked questions of nonlethal weapons technology, the physiological responses observed in clinical settings of the biophysical coupling and susceptibility of personnel to nonlethal effects weapons. These results identify and validate some aspects of maturing nonlethal technologies that may likely be encountered or used as nonlethal effectors in the future including:

• Laser and other light phenomena.
• Radiofrequency directed energy.
• Aural bioeffects."

It contains a list of ‘incapacitating effects”, together with a description of the underlying related biology and physics, how to achieve the effect using technology, how tunable the effect could be and the effects on the targets. Among the listed effects, there are two of special interest for the current subject:

Microwave hearing

Humans perceive sounds when exposed to pulsed microwave radiation. It is stated that the phenomenon was first documented in the 60s and the consensus on how the effect happens is that its cause by thermoelastic expansion of the brain, caused by the microwave pulses, which are then processed by the cochlear microphonic system, which created the perception of sounds in the brain (thus not being detectable by microphone or listenable by anyone who is not being hit by the microwaves). Without any refinement, the perceived sounds look like buzzing, ticking and hissing, but, so the paper says,  “If refined (..) could be used to (..) communicate even by voice”. It further details (emphasis mine):

“it seems possible that this technology could be developed to the point where words could be transmitted to be heard like the spoken word, except that it could only be heard within a person's head. In one experiment, communication of the words from one to ten using "speech modulated" microwave energy was successfully demonstrated. Microphones next to the person experiencing the voice could not pick up the sound. Additional develonment Of this would open up a wide range of possibilities.”

With regard to the effects on the target, they put it (emphasis mine):

“Application ofthe microwave hearing technology could facilitate a pdvate message transmission. It may be useful to provide a disruptiv€ condition to a person not awaxe of the technology. Not only might it be disruptive to the sense ofhearing, it could be psychologically devastating if one suddenly heard "voices within one's head. “

With regards to the required technology, it is said:

“Microwave energy can be applied at a distance, and the appropriate technology can be adapted from existing radar units. Aiming devices likewise are available but for special circumstances which require extreme specificity, there may be a need for additional development”

And they declare “The effective range could be hundreds of meters.”

Disruption of neural control

This effect is of special interest since it seems to be the one referenced by whistleblower Barrie Trower (see the Whistleblowers Section) in his interview with Alison Smith (in which he claims over 600 physiological and neurological effects can be produced with pulsed microwaves) and which he directly associated with the targeting. The effect is summarized in the document as:

"The nature of the incapacitation is a rhythmic-activity synchronization of brain neurons that disrupts normal cortical control of the corticospinal and corticobulbar pathways; this disrupts normal functioning of the spinal motor neurons which control muscle contraction and body movements. Person suffering from this condition lose voluntary control of their body. This synchronization may be accompanied by a sudden loss of consciousness and intense muscle spasms"

The paper goes on to describe the general physiological mechanism behind it, but focuses on the epileptogenic effect ("Because the neurophysiological mechanisms of epileptiform synchronization are better documented, this incapacitating technology described in terms of epileptogenesis"). It seems too technical for inclusion here and the qualified reader may refer to the original document for the information.

Regarding the mechanism to reproduce the desired effects, it states:

"Application of electromagnetic pulses is also a conceptual nonlethal technology that uses electromagnetic energy to induce neural synchrony and disruption of voluntary muscle control. The effectiveness of this concept has not been demonstrated. However, from past work in evaluating the potential for electromagnetic pulse generators to affect humans, it is estimated that sufficiently strong internal fields can be generated within the brain to trigger neurons. Estimates are that 50 to 100 kv/m free field of very sharp pulses (~ 1 ns) are required to produce a cell membranic potential of approximately 2 V; this would probably be sufficient to trigger neurons or make them more susceptible to firing."

On the possible influences on the target, it states (emphasis mine):

"If the technology functions approximately as envisioned, the targeted individual could be incapacitated very quickly. Because there have been no reported studies using the conditions specified, experimental work is required to characterize onset time. Different types of technologies could be employed to influence wide areas or single individuals. Because this technology is considered to be tunable, the influence on subjects could vary from mild disruption of concentration to muscle spasms and loss of consciousness. The subject(s) would have varying degrees of voluntary control depending on the chosen degree of incapacitation."

As with the microwave hearing effect, they declare “The effective range could be hundreds of meters.”