What are Nerve Signals?

Pulses.

Wikipedia has a well worded 'short answer':

Action potentials in neurons are also known as "nerve impulses" or "spikes", and the temporal sequence of action potentials generated by a neuron is called its "spike train". A neuron that emits an action potential is often said to "fire".

The optic nerve? Sound and smell? These are different. See this Wiki article for more.

I would say FM..........F@#king Magic

AM, FM, video encoding, etcetera are machine systems invented by man. They have no direct correspondence to the innate encoding of the nervous system, which we do not presently know and therefore cannot mimic (ie we can't build a machine that matches organic neural encoding - you can't plug video or AM/FM radio into a nerve and expect to produce anything but "nerve noise").

There are now machines which directly take off and interpret neuro signals.

I am afraid man can invent basically NOTHING ! All inventions are based on some analogy with what already exist in nature.

Cochlear implants come close, and the now-under-testing-and-evaluation auditory nerve implants come even closer. They do actually mimic nerve impules.

Of course that's one type of nerve impulse...millions to go

I thought the cochlear implants were another type of hearing aid, basically an amplifier with carefully selected parameters.

I'm familiar with the 'microstimulation' implant tech - I think it's a stretch of the imagination to say that these mimic nerve impulses. That is like comparing a jackhammer to a birdsong, or an A-life algorithm for self-organizing systems to an actual organism.

DBS and VNS type implants essentially interrupt the flow of neural signals, which is therapeutic using specific pulse train parameters, in some cases of parkinsons (DBS) or epilepsy (VNS), because the flow of signals is pathological and is forced to reorganize by the 'jackhammer'.

I am completely sceptical about "auditory nerve" or "optical nerve" stimulation therapies, since I see no reason to believe that the mindless 'jackhammer' to the nerve will be translated into coherent 'actual' sound or sight. I do keep an eye out for news on the research, but so far I've seen nothing convincing or really promising in the sensory department at all.

I am afraid it will be learned one day how to induce certain kind of signals in live organisms to make possible manipulation with people. Not parapsychologically, but purely scientifically.

It all depends what you mean by 'manipulation'.

Brute force coercion is one means of 'manipulation' ie to get behavioral control. So for example, if you google "VNS choking" you can see that, if criminals got a VNS on you for coercion purposes, they can choke you by remote just by turning it "on". If there's amplitude control, they can make it worse by ramping it up. For more sophisticated abuse of this device, different parameter settings (pulse frequency, waveform, duration, etc..) could be used to cause a variety of unpleasant effects, ranging from gastric upset to shocks around the heart (vagus nerve is extensive!) or pseudoepileptic seizures.

Any muscle groups can be manipulated remotely by stimulators and made to twitch. But I doubt you would get coordinated movement control unless the person is heavily sedated and/or cooperating. It was reported they were able to 'walk' an anaesthetized cat, more than twenty years ago. And we've all heard of robo-rat.

Any stimulator that's high enough amplitude could be used for "chinese water torture" type effects - the repetitive pulse sensation or twitching. High amplitude can also be used to produce pain or "shocks". Any impulse that can wake a person up can be used for sleep deprivation - all classic means of 'manipulation'.

All in all, a person could be seriously impaired and abused with present day microstimulator technology, for behavioural control by violence and intimidation.

If the intention is to deceive, that could be done as well, if brain stimulators are considered. "Special effects" have been reported, like creepy sensations that someone is standing behind you, for example, by stimulating the insula region of the brain, or a "silent voice" effect - the perception that someone is speaking to you although nothing is heard - by stimulating the auditory cortex. And, can't leave out the 'orgasmatron'. That could be a means of manipulation too.

Still, I'm pretty sure there's no intelligible audio without an ordinary amplifier. Happy days. They'll have to get you alone to make audible threats or demands.

Of course, anyone who used these means would do best by utterly deceiving the victim, for the sheer terror power of it, and of course, handy for not getting caught. If the victim is impaired or ignorant enough to be effectively deceived about some bogus cause (aliens, vampires, gods, pick your classic...) then they're going to look craaazy, and may be willing to do crazy things, and you know, that's got to be good for business.

(ending post 6) For non-humanistic and unethical political or economical ends.

I probably overestimated the complexity of the machine I heard about recently. It looks like a body-like shell which man invest himself in and which makes him tenfold stronger. Intended for battlefield - sort of "super solder" is the result, I do not remember the precise terminology. I thought at once it intercepts directly brain impulses to muscles (decode them, etc) - but it is probably more simple: tactile probes just sense movements of body and then the man-like machine is made to mimic the movements.

Search "BCI" or "Brain Computer Interface" for more about the interesting technologies for assistance to the disabled.

They're "digital"

Under different emotional conditions,our brain and nerves or even muscles will react differently generating signals of various amplitudes and frequency. They say even the electrical resistance of the body depends on emotional conditions,have any body got measured values?.

The latter is easiest.

Investigators measure with lie detectors.

When one gets nervous his/her skin sweats, resistance falls.