Neural Disruptors

[nbk2000]

I was reading this months issue of Scientific American, when I saw an article about TMS (Transcranial Magnetic Stimulation), which is the use of electromagnetic fields to stimulate the synapses of the brain.

In the experiments (funded by the US military, naturally), they found that the EM fields only penetrate a centimeter or so into the brain tissue, but that's only at "safe" energy levels.

The "unsafe" energy levels cause seizures and destruction of neural pathways. :)

I'm envisioning a contact range weapon that uses the new ultrahigh density aerogel capacitors to retain a very high amperage charge, which would then be directed into the emitter, which is pressed against the targets head. A switch would be built into the head of the ND so that, when pressed against the target, it would instantly discharge the energy as a high flux field into the victims brain.

This could have applications as a wet-ops kind of weapon, killing the victim in what would appear to be a stroke or other natural cause, since there'd be no residuals of any sort to indicate foul play.

There was a book published many years ago, the title of which I have long forgotten, that described the uses of EM fields to alter brain functioning. The technology was primitive, but it had succedded in giving me the idea for something like this, and the deep pockets of Uncle Sam have finally started to bring it about. :D

[Mr Cool]

I've read a report on tests with pulsed magnetic fields and brains. A woman was asked to count, and a pulsed magnetic field was applied to her head. It basically went:
"One, two, three, four [field applied] four, four, four, four, four [field removed] five, six, seven..."
Weird...

I also know of someone who was temporarily messed up by moving in an NMR scanner. An experiment was being carried out to see which bits of the brain were active when listening to different sounds, stories, music etc. So the volunteer was listening to the sounds on some special headphones, which slipped off. He instinctively whipped round to catch them... neurons in brain (conductive) rapidly moving in a field that will pull off a belt buckle from the other side of the room and propell it with enough force to break your arm... I can't remember exactly what the effects were, but it didn't sound fun.

[nbk2000]

She didn't notice she was stuck? Hmmmm....:D

That'd be just the thing to put on someones head! Apply a little EM field to the noggin', person goes into "Stuck" mode, you do what you want, and when it's removed the person doesn't even know anything happened.

'Course, if you had to stick a device over their head to do it, they might notice...but if it could be done remotely....oh, the possibilities! :)

Even if it was a device, that could have uses a an EM "handcuff" to immobilize a hostage/kidnapee', or as an electronic "date rape drug" that would immobilize the victim without leaving any of those pesky metabolic traces that could be used as evidence. :p

As long as these sorts of devices were extremely esoteric, and thus not common knowledge (at least to the cops/feds), no one would believe that the guard couldn't move, or that the woman was helpless, when there's no marks or signs of drugs/restraints. ;)

There's an article on the 'net somewhere called "The mind has no firewall" that describes these sorts of weapons being developed by the military.

Given the inverse square law, the power required to "zap" an area about the size of...oh, say....a bank ;)...would be VERY large. However, if it was a pulse, rather than continuous, then that could be managed by capacitor banks. Flip the switch, everyone within proximity to the van or truck the device was in (BIG capacitors, don't you know!) goes into stuck mode for a few minutes, and the crims go about their business.

[Mr Cool]

I think she might have been aware of what was happening, she just couldn't do anything about it. Like a CD player with a scratched CD, that causes it to get stuck. The CD player knows it's playing the period of time 3:12 to 3:14 over and over again, but it is powerless to stop doing it.

That'd be freaky. Knowing that you were saying four over and over, but not being able to stop yourself! Though that effect would not be as useful as "stuck mode."

Anyway, I think that's how it was. It's a long time since I read it.

[nbk2000]

If, instead of saying "four", you were told to walk, but were "stuck" in your chair because you couldn't get yourself "unstuck" from sitting, then the fact that you were aware of your "stuckness" really is irrelevant, because you can't do anything to change it.

If everyone in a bank was "stuck" doing what they were doing at the instant the TMS device was activated, and couldn't stop me from clearing the place out, do I care that they can see me doing so? Not really, since the only important thing would be that they couldn't stop me. :)

[James]

I don't suppose you could use a parabolic (or near parabolic) reflector to increase the range of the device? Also a Faraday cage could probably be used to block at least some of the effect.
edit: I just did some quick reading. appearently they don't like releasing details. :( I think this (http://www.ists.unibe.ch/sciam.pdf) is the article reffered to by NBK. Appearently the FDA doesn't want this used (http://www.cadwell.com/support/pdfs/MES-10%20FDA%20Policy.pdf) for 'cranial stimulation'.

[Arthis]

The Faraday cage works if the electromagnetic signal comes from outside the cage. As noone will keep a "Faraday helmet" all day long, it's pretty difficult to set up.

By the way, I need a few precisions about Faraday cages: I think they work because the electromagnetic wave has an electric dimension, that make electrons move in the metal wires of the cage, thus acting like a metal plate. The wave is partly reflected, and quasi nothing goes trough the cage.
The wave is stopped only if the lenght between 2 wires is lower than the wave lenght (lambda = c/f , with c speed of light, f frequency of the signal).
Am I right ?
Because then it may not be easy to create an effective Faraday cage against that, depending on the frequency of the disruptor.

btw, neural disruptors were imagined by Dan Simmons in the Hyperion cycle.

[Tuatara]

Arthis, you have the description of a Faraday cage pretty much correct. You will get minimal attenuation for a gap size greater than 1/4 wavelength, gradually increasing to perfect shielding for solid metal, assuming infinite conductivity. For real metals the shielding effect is also dependent on the thickness. This is where the 'skin effect' comes into play. The attenuation factor is

-az ______________________________
Attenuation factor=e , a = \/( pi x Frequency x mu x sigma),
Where z is depth, mu is permeability of the metal and sigma is conductivity of the metal
and frequency is the frequency of the EM wave


Both the magnetic and electric fields are involved.

[zeocrash]

i think the getting stuck thing is caused by the brain's inability to communicate with various other parts of the body, rather than the brain not being able to work out what it is doing. i saw another interesting effect in a documentary about the body once, the documentary involved a woman who was going into hospital to have a tumour removed from the language centre of her brain. to find the language centre the woman was asked to count upwards while a surgeon poked around ther open skull with a set of electrodes with a tiny voltage running between them. when touched on the language centre, the woman was completely unable to speak and all her counting changed into a slurring gurgling noise, the electrode was removed and she was able to count again.

[A-BOMB]

Last months Scientific American had something along these lines I'll see if I can scan it in.

[Arthis]

What you say zeo wouldn't explain why the person keeps saying "4": a number is a complex sound to tell, and a simple unability for the brain to communicate with the rest of the body (or even part, as otherwise the person would stop breathing) could not allow that.

Yes Tuatara, and if the skin effect is too deep into a too thin metal layer then you've got an antenna on the opposite side. But the attenuation still is pretty good, considering most of the energy gets reflected, and another part is lost in the metal (Joule effect). A helmet would be a good protection in fact.

[Tuatara]

Arthis, I wasn't saying it wouldn't work! In fact, if you go through the numbers, any easily handled thickness of metal will provide a very effective shield, especially if it is ferromagnetic. Example: a nickel shield only 100um thick will provide a very effective shield down to quite low frequencies. The best materials for shielding are combinations like silver plated Mu metal (a nickel / iron alloy)

[Arthis]

Researches on TMS are done to determine ways to use it as a cure. For example, some one armed people feel a pain in their missing arm, due to special brain reorganization. The TMS seems to allow a better plasticity of the brain.

If TMS can be used as a weapon, it can be used too as a powerful body enhencer that one could have at home.

I remember having read a few years ago about special wave lenghts used to make you sleep better. The principle was to imitate some of the magnetic fields the brain produce in some critical periods to re-apply them, forcing the brain to have the activity you want: at that time, what had interessed me was the possibility to make you sleep so deeply that you only needed a few hours of sleep (2-3) to feel totally restored.

There may be some even better possibilities:

There were significant improvements with TMS for performance in the digit symbol substitution and verbal fluency tests, but no change of mood on a number of measures. There was also a reduction of pulse rate after TMS. The only side-specific TMS-effect was on mean arterial pressure, which decreased pressure after left, but not after right prefrontal TMS.


In other work, scientists are finding that additional brain ailments may benefit from TMS. For example, researchers found that TMS applied to the front part of the brain speeds up the ability of healthy volunteers to solve puzzles requiring skills in analogical reasoning.

I would like to search a bit more on that topic to make one for myself (who knows, maybe I'll become a genius ;)).

A little PDF (http://web.sfn.org/content/Publications/BrainBriefings/BrainBriefings_Feb2002.pdf)

The frequencies used are between 1 and 100 Hz normally, 1 Hz being the one used for the first quote: link (http://www.biomedcentral.com/1471-244X/2/1/abstract).

If any of you has information about the effects of different frequencies, I would be really interested: as TMS is under research, there isn't much information available, though I'll look further on Google.

BTW, the frequencies used (over 1 Hz, and most between 25 and 100 Hz) mean that it's quasi impossible to make massive Faraday protections, e.g. for bank employees, other than a full metal helmet.

[grandyOse]

I have read quite a few reports on these types of weapons. Mixing the reports with a large NaCl crystal, and seiving it through my knowledge base, I have come to these conclusions:

1) you need a carrier wave to transmit the brain wave. This can be either audio (sub or super sonic) or EM (radio frequency energy). A sound wave within the human hearing spectrum would have it's obvious uses and dissadvantages. This carrier should be resonant with body structures such as small bones for ultrasonic, or emission / absorption spectrum lines for water, hemoglobin, etc in the case of an RF carrier. The carrier could also be a bright light shone into the victum's eyes.

2) The modulating frequency should mimmic brain waves. They could "capture" an alpha wave and slowly slide in frequency to the desired wave (sorry, I don't remember the names of all the brain waves and their associated states). The russians did a lot of experiments in this regard. 13 Hz produced a sense of dread, and 77 Hz made the subjuect incontinent. I wish I could remember some others.

3) If the carrier is precisely tuned to a receiving structure ( I find this unlikely) then you can frequency modulate the carrier with the brain signal. Otherwise, you are better off with amplitude or pulse modulation. The pulse should not be PCM or some other scheme; just an overdriven & clipped Am modulation.

4) sorry I don't have any hard data. These posts on this thread, so far, are mostly speculation anyway, so I thought I would join in. I am very tired of component level electronics and do not intent to take on this project. I have too much on my plate now as it is.

[TRUTHSEEKER]

From previous readings on "Scalar wave weapons" from about a year or so ago, I read that your brain has a "time base". It's possible that the strong magnetic field is able to disrupt or temporarily suspend your brain's time base. Oh, the possibilites...

[Jhonbus]

13 Hz produced a sense of dread, and 77 Hz made the subjuect incontinent. I wish I could remember some others.

Are you certain this is not data referring to the effects of infrasound?

[grandyOse]

I'm pretty sure the 77Hz was directly applied electric current, although the 13Hz figure may have been sonic. At these frequencies, I don't think the ear has as much response as bones and other large structures for sound waves. I don't think it much matters whether the source is sonic, optic, directly applied current, or electromagnetically induced. anything that would set up oscillation in the nervous system ought to work equally well. I could be wrong about this, as my reliable data on the subject is over 20 years old, and in my holey memory only.

Anyone with some electonics skills and a kid brother want to test this out? Try directly applied sinusoidal (LOW current) and pulse voltage source at the temples. Try a strobe light, and try infrasonic (good luck finding a transducer, a large diameter 30' long pipe might work). Also try an ultrasonic wave modulated at the low frequency. Also try a large electromagnet modulated with the same signal generator used on the subject's head. Perhaps a human sized paint-shaker driven at the correct frequency would also work. Actually, this paint shaker wouldn't be that hard to make; put a semi-circular flywheel on an electric motor and mount it to a chair that has at least one degree of freedom. Of course sitting a shaking chair is going to induce some kind of negative reaction, but it could be used to test effects versus frequency. I would stay away from the RF carrier method. It would probably be one of the better real-life methods, but could prove hazardous to kid brother. Try all these methods with the same frequency at first, to limit the variables. A second test round would be to determine frequency versus effect, and if the effectiveness of the various induction methods varied with frequency.

Does anyone recall the Japanese cartoon that featured a monster with eyes that flashed at a rate that would induce sezures in some significant percent of the viewers? Was this a myth?

[nbk2000]

It was called "Pokeman"

[simply RED]

There was an article in a magazine about that cartoon. It was written : "red flashes from 7 Hz up to 1 kHz can produce sezures in the viewers".
I tried it with modulated red laser light on myself and it had absolutely no effect.
There was also an article about ultra low radio frequences. And it says the 77 and 13 herz were emmited with high inductivity antena as radiowaves....
I don't think this will work...

There is a possibility to use microwaves. If not mess up at least torch up the victim's brain. This of course is only possible in theory... but possible anyway...

[nbk2000]

Flashing lights induce seizures only in people suceptible to them, with the percentage of the population being affected decreasing with age, as children are more effected than adults.

[simply RED]

If a psychoactive field exists its characteristics must be understood and after that - used.
Lets hunt in the electromagnetic field.

1. ELF (Extremely low frewuences)
2. Radio waves. (800 kHz - 3 GHz)
2.1 UHF
3. Microwaves.
4. IR
5. Visible light.
6......
Obviosuly 2,4,5,6.... have no influence.
For the whole spectre of 1, 2.1 and 3 I have no reliable info.

[Xave]

I think i read that same article in N.S. you're referring to. I also had a similar idea! a siezure inducer. i did a little research, i think the problem with a device like this would be the susceptibility of your targets. Some individuals brain-waves are not easily 'trained' into the frequency of the e.m. field.

The induction of seizures however, is quite crude and non-specific. E.m. pulses every 1-8 seconds are considered something of a risk with T.M.S. so fast, intense pulses would be likely to induce incapacitation through seizures!

[nbk2000]

Heating of the brain itself, by just a degree or so, within a couple of minutes is supposed to induce seizures, much as someone with a high fever can begin convulsing.

The trick is how to heat the brain without cooking it like an egg in the process. :o

[Bander]

I am in the nearing the end of building a homebrew transcranial magnetic stimulation device for it's intended use. It will not work as a weapon. To induce the proper e-field intensities needed to depolarize neurones and thus get them to fire one needs a magnetic field strength in the order of 2-4 teslas--something that's not easy to do, especially with the inverse square law working against you. The range of any such device will be severely limited. Unless one can borrow the sandia z-pinch marx generator I don't foresee any more distance than direct application of the coil to the subjects head. It is not economically or physically feasible. Your capacitor bank would have to weight hundreds of pounds, coil cooling would be huge and complex, and repeated firings, that is rTMS would be near impossible--it would take megawatts of continuous power.

Also, about capacitors. Aerogel caps will not work. They are low voltage, typically in the ~1-10v range with moderately high equivalent series resistance. Since pulse rise time is the most important factor for successful TMS they will not work (as I'll explain below)

Most commercial TMS devices are pulsed with a thyristor. They use, on average, a ~3000 volt 20-200 microfarad capacitor (not electrolytic, the back emf will destroy it most of the time) through a stimulation coil of 15-30 microHenries. Pulse length is typically in the 100 microsecond range as neurons act as leaky integrators with a time constant of ~150 microseconds. So the shorter the pulse the less energy you need to depolarize the nerve. So you see why aerogel caps won't work. The pulse rise time is to slow to generate an appreciable efield. Far, far too slow.

Anyway, one can duplicate the works of companies such as MagStim and produce a normal transcranial magnetic stimulation device with little capital investment. The hardest part is switching the high voltage high current pulse. I've chosen to go with a triggered spark gap. I'll walk through my design.

A transcranial magnetic stimulator is not altogether different than a low powered magnetic can crusher I imagine many of you have seen online. Here's an copy of my circuit:

2969v, 320uf, 20uH, 0.375 Ohm
Peak Current: 5182.54 amps
Time Ipeak: 0.09 milliseconds
Pulse Width: 0.20 milliseconds
Voltage Reversal: 1.42% , -42.26v max
Damping: Under

http://wetwarewiki.com/tms/device_psuedo_schem_sm.gif

Okay, first and foremost one needs energy dense capacitors that will be able to handle being shorted through an inductive load and of the voltage required to keep the pulse short. Energy needs to be at least above one kilojoule. I aquired my capacitor bank off of eBay, it totals 320 microfarads at 3000v. That's 1440 joules total (energy = 1/2(farads)(voltage)^2). It is made of two unused 160uf (microfarad) 3kv photoflash capacitors that were intended for use in ultraviolet water purification. I bought them for $15 each on eBay (an amazing deal). You can try non-pulse rated filter capacitors if that's all that's available as they are cheaper and more plentiful.

http://wetwarewiki.com/tms/capacitors.jpg

Second you need a power source that is able to charge up the aforementioned capacitor bank in time to make it useful--that is, able to operate at >1hz or so. Single pulse TMS has not been found to cause seizures in healthy patients, 10hz and above has. The easiest way to do this is to get ahold of a microwave or two and take out the microwave oven transformer, or MOT as we say in the hobby, and the high voltage diodes. You'll need 2 MOTs, and preferably 2 diodes (4 for a full wave rectifier, we won't be doing that here, but it gives more current), but you can get by with one. So, in order to prevent the MOT from drawing too much current and blowing a breaker or fuse you need to inductively ballast it, that's what the second MOT is for. In the diagram below you can see that one MOT has it's secondary shorted out and has it's primary placed in series with the line the second MOT is powered from. This should limit the current to under 20 amps. This will give you an AC current of ~2100v. But AC will not charge a capacitor, so you can rectify this (pun intended, ;P ) by putting an appropriately rated diode (the one from the microwave will do) in series with high voltage (secondary) output of the second microwave. This will give you what is called half wave DC, and will pulse at 60hz. Now, when you rectify AC and turn it into DC the voltage is affected. You will have sqrt(2)Voltagepeak. That is, sqrt(2)2100v = 2969.4 volts, which is perfect for charging out capacitors.

http://wetwarewiki.com/tms/MOTWiring.gif
http://wetwarewiki.com/tms/MOTWiring.jpg
This is just a mockup using old parts, btw. The actual device is scattered across the basement at this point.

Now, you can hookup the capacitors to the power supply above and they will be charged to full voltage relatively quickly, but how do you switch that power into the stimulation coil? Commercial devices uses expensive thyristors and load balancing, that's beyond me. But one can switch high voltage and high current rather effectively using a device called a trigatron, or triggered spark gap (though there will be resistance losses and voltage drop ~200v). The idea is to take two small doorknobs and drill a hole in the center of one, sticking an insulated electrode inside. These doorknobs are then placed just far enough apart (perhaps a little farther to cut down on corona losses) so that when put in series with the power supply the current does not arc across. That's the spark gap part. The triggering is done by putting the insulated internal electrode and the doorknob surrounded it in a circuit wherein high voltage low current is pulsed (a cheap stun gun does this job admirably if one does not have the knowledge to make something, or is lazy). This generates a conductive plasma that will be drawn out into the gap between the two doorknobs by the efield and trigger a discharge of the capacitor bank. As for timing, I leave that modification to you. A simple 555 circuit can be used to control the stun gun, or you could leave it be and hope the stun gun's rep rate is appropriate...or go with a single pulse trigger. Perhaps a few pictures will explain better. Putting a fan perpendicular to this gap will help with quenching. It needs to be a pretty strong fan when using MOTs.

http://wetwarewiki.com/tms/tsg_ani.gifhttp://wetwarewiki.com/tms/tsg_schm.gif

So, the last part one needs is the stimulator coil. This, arguably, is more important the capacitors even if it's easier to make/aquire. And it is this that will make or break your device's efficiency. The coil shape will vary depending on the application it is to be used for; brain stimulation or peripheral nerves, etc. There are three types of coils of varying strengths and weaknesses on the market today-- circular, figure-8, and some funky flat half toroid of which I know little about. Circular coils typically offer higher efficiencies but with lower resolution of stimulation. Figure eight coils offer moderate efficiencies with higher resolution in nerve activation (5mm). For this context a circular coil would be best, and luckily the easiest. Construction is simple, using 16 gauge or lower wire (to handle high peak power and resistive heating) wind a circle with 15-18 turns and an inner diameter from 60-70 mm and an outer diameter of 85-95 mm. It should be wound pancake style, not like a solenoid. If one is going to make a high repition rate device heating will become a problem, at these currents and voltages most current is carried on the outside 'skin' of a wire, as such you can use hollow tubes and run liquid coolants through to keep the coil from overheating. I have not done that with my design. It's best to encapsulate the coil in expoxy if one can.

http://wetwarewiki.com/tms/coil1.jpghttp://wetwarewiki.com/tms/coil2.jpg

And there you have it, your own transcanial magnetic stimulation device that can be built for under $100. You can try upping the power by using higher energy capacitors but it will get bulky. My device is already suitcase sized. A few tips: try and use large diameter wire in construction to keep resistance down, and mind the high voltage as being shocked by a running MOT will kill you.

If needed I can upload a wealth of information in pdf format on TMS to the FTP. But I highly doubt it will be called for since TMS cannot be made into feasible weapon system.

[nbk2000]

All information is good information, so upload it please.

And, just because you haven't made it into a weapon, doesn't mean someone else can't figure out how to. :)

Even just for its original harmless purpose, that's good to have too, as being able to stay up for several days at a stretch without being tweaked out or zombified could be vital to the success of a "mission".

While inverse-square may make it impracticle for distance killing (for now), the original point of this thread was a non-detectable means of killing, even if it had to be point-blank. A knapsack sized device with an attached "wand" that could be applied to the victims head to short out their brain would still be feasible, as it could be carried by a "bike messanger" who'd just so happen to get onto the same elevator as a target.

I'd not be worried about the power storage issue, as superconductor research goes on and will eventually solve that problem. The important aspect is to have the device requirements (frequency and such) solved first, and watch as the components continue to shrink, 'till one day you have a flashlight-sized brain cooker. :)

[simply RED]

Will a microwave oven magnetron pointed and "fired" at someone's head have some effect?
Obviously the answer is yes. The microwaves go through the matter and heat the water as they resonate with the H2O molecules (rotational energy). Obviosuly the magnetron is possible to power with the current sources no matter the device will be big.
Someone has microwave air abosorbtion diagram?

[Bander]

And, just because you haven't made it into a weapon, doesn't mean someone else can't figure out how to. :)
Quite right. My skill is far from (read: below) average when it comes to this field. Sometimes I get ahead of myself. :p

Will a microwave oven magnetron pointed and "fired" at someone's head have some effect?
Obviously the answer is yes. The microwaves go through the matter and heat the water as they resonate with the H2O molecules (rotational energy). Obviosuly the magnetron is possible to power with the current sources no matter the device will be big.
Someone has microwave air abosorbtion diagram?
Here's a "COMPILATION OF THE DIELECTRIC PROPERTIES OF BODY TISSUES AT RF AND MICROWAVE FREQUENCIES (http://wetwarewiki.com/tms/DIELECTRIC/Report.html)" I've uploaded. It should answer most questions. Er, unless you were asking about how air affects the propogation of a microwave signal--which is negligible when compared to other factors.

Also, a few more goodies with respect to microwave weapons.

Microwave weapon damage to humans can be divided into hard and soft lethality. Hard lethality means burning of human flesh. At a frequency of ten gigahertz the energy density of an individual pulse that can effectively burn [human flesh] is 100 joules per square centimeter. As the frequency increases, the threshold value of the burning effect is lowered. For example, at several tens of gigahertz, the energy density of an individual pulse that can effectively burn is just 20 joules per square centimeter. Soft lethality of microwaves against human targets means destruction of human nerves and hearing. After brain tissue absorbs an electromagnetic pulse, it slightly but rapidly expands and produces a supersonic wave which is recieved by the inner ear. If the electromagnetic pulse energy exceeds the threshold and the supersonic wave is too strong, the human ear will not function. The greatest electromagnetic pulse energy that the ear can accept is 0.04 joules per square centimeter.
http://wetwarewiki.com/tms/microwave_gen.gif http://wetwarewiki.com/tms/cornu.gif
Trends of Microwave Weapon Developement (http://wetwarewiki.com/tms/TrendsofMicrowaveWeaponDevelopment.pdf), a China Aeronautics Industry Corporation document, translated by the US National Air Intelligence Center.

[nbk2000]

Since the energy to deafen is 1/500 of that required to burn, it seems most practical to use a MW weapon as a means of deafening an enemy, possibly making them unaware of your impending attack.

Though, the fact that they went suddenly deaf will not be overlooked for long, I'd think. :D

Combine deafening with smoke, and you protected by shielding and using TI, you'll have achieved [MIL-SPEAK]Total Spectrum Dominance[/MIL-SPEAK]. ;)

As a terror weapon, deafening someone would rank low compared to blinding someone. Can MW be used to destroy optic nerves, eye tissue, or induce hazing of the corneas?

[vulture]

If you want to fiddle around with brainwaves without buying expensive components, try looking into the older versions of Cool Edit. It had a function to produce certain harmonic frequencies that could cause you to relax or something. I think it's the '96 version that had the function.

[yawehzuv]

I have heard you are never supposed to operate a microwave with the door open because the microwaves come out and screw up your eyes. I think this is because of your eye containing lots of water to heat up. So I think any microwave could blind somebody.

[Bander]

As a terror weapon, deafening someone would rank low compared to blinding someone. Can MW be used to destroy optic nerves, eye tissue, or induce hazing of the corneas?
The below is a half-assed summary and misc edited images from the extremely long document "Effects of Acute and Prolonged Millimeter Wave Radiation Exposure Upon Corneal Endothelial Morphology.pdf" which, at 5.49MB, weighs in at a few MB too many for me to host so I've uploaded it to the ftp.

Unfortunately primates in particular are well shielded when it comes to the eyes. In an experiment wherein rabbits and rhesus monkeys were irradiated with 2.45Ghz (that is, standard microwave oven frequency) for varying times of 10 minutes to 120 minutes to figure out how the thresholds for cataracts to appear rabbits started clouding up at 100 mW/cm2. The monkeys had facial burns but their eyes were not damaged even at power densities of 500 mW/cm2. Apparently this is becuase the primate bone structure of deep-seated eyes shielded by well developed brows not only block some radiation but instead of causing localized heating on the lens, the vitreous humor was heated instead. Thusly the key figure of 45*C (or, 5C over normal) for the lens to cause damage was never reached. I imagine the situation would be analogous among humans even with our slightly less pronounced brow lines.

I'm getting the feeling that causing damage to the eye is going to take quite a bit of microwave power--enough such that the burning is going to happen first, so no sudden unexpected blinding. Damn.

http://wetwarewiki.com/tms/tissuethermalconductivity.gif http://wetwarewiki.com/tms/tissueat245.gif
http://wetwarewiki.com/tms/heatat245.gif

[nbk2000]

Well, maybe eye flambe' is out of the question, but feeling your face suddenly burning and feeling like it's going to slide off the bone (remember that scene from "India Jones" when the Nazis opened up the Ark of the Covenant? :D) is certainly going to be a distraction.

Wonder how well protected the genitals would be? You'll usually find a nice metal antenna suspended right over the family jewels, prime for catching heat from the MW.

BURNING NUTS! :eek:

:p

[simply RED]

Burning brains and other body parts will be great, but...
The ultimate goal will be to achieve transmition of sound with some kind of radiation. The sound must be "heared" directly into the brain.
The device must have the ability to be pointed directly onto the "percipient".
Will the microwaves help? Maybe.
As it was said they are "catched" by the brain and turned to supersonic wave - which demages the hearing.
If the process is linear, not binar, modulating the waves (amplitude or impulse) may induce sound sensation.

The genitals are succeptable to irradiation, I suppose.

[nbk2000]

I've heard of using directed energy to transmit sounds by stimulating the nerves of the (brain or ear, one of the two), thus causing the "Voice of God" effect in their head.

Supposedly, the TFH (Tin Foil Hat :D) crowd has all the research references for this effect, so look for that.

Could be used for discrediting someone by making them appear crazed.

[simply RED]

http://www.mindcontrolforums.com/p/usp4,877,027.htm

true?

[nbk2000]

It is a real patent, so that part is true, and the explanation in the patent matches with what I've read, so it's seems feasible.

[nesler]

Another (http://www.mindcontrolforums.com/mindnet/mn132.htm) interesting article ("Synthetic Telepathy") that I came upon at that site.

[Jacks Complete]

For blinding weapons, you don't want to be using microwaves - they just don't work. Some of the frequencies (may apparently) cause spots to appear, but nothing much, really.

The solution is to shift the frequency up a bit (like several orders of magnitude).

A pulsed UV laser will cause burns to the cornea surface, as all the short wavelength UV is absorbed, causing a cateract. The laser need not be pulsed, but if you can find a CW UV laser that isn't room sized, what with the PSU and water cooling, I would be suprized.

There is an old Scientific American "Amateur Scientist" article, dated from some time in the 60's which tells how to make one. Sadly, I don't have a copy any more, but you might be able to hunt one down. It details the production of a single shot UV Nitrogen laser, pumped by a flashlamp which it triggered via a spark gap. There is a modification to a cooled, continuously running high pulse rate version, and it is easily a class IV laser. It is also rather small, considering.

A little less subtle, but more long term damaging, would be a pulsed laser anywhere in the range for eye transmission, which goes from near-UV to fairly long wavelength IR. Power levels don't need to be very high, a short pulse will do, and the target will not be able to tell where the shot was fired from. Bystanders will, if they were luckily looking in just the right direction. However, this can be mitigated by the use of an IR laser, which would be invisible to the naked eye.

Higher powered diode lasers can be obtained, some of which (comms ones) run at long wavelengths for IR tranmission in fibre optics.

The effects of a laser hit are described here:
----
CASE HISTORY NO. 1

This is an accident victim's viewpoint of his experience.

The necessity for safety precautions with high-power lasers was forcibly brought home to me last January when I was partially blinded by a reflection from a relatively weak neodymium-yag laser beam. Retinal damage resulted from a 6-millijoule, 10-nanosecond pulse of invisible 1064-nanometer radiation. I was not wearing protective goggles at the time, although they were available in the laboratory. As any experienced laser researcher knows, goggles not only cause tunnel vision and become fogged, they become very uncomfortable after several hours in the laboratory.

When the beam struck my eye I heard a distinct popping sound, caused by a laser-induced explosion at the back of my eyeball. My vision was obscured almost immediately by streams of blood floating in the vitreous humor, and by what appeared to be particulate matter suspended in the vitreous humor. It was like viewing the world through a round fishbowl full of glycerol into which a quart of blood and a handful of black pepper have been partially mixed. There was local pain within a few minutes of the accident, but it did not become excruciating. The most immediate response after such an accident is horror, As a Vietnam War Veteran, I have seen terrible scenes of human carnage, but none affected me more than viewing the world through my bloodfilled eyeball. In the aftermath of the accident I went into shock, as is typical in personal injury accidents.

As it turns out, my injury was severe but not nearly as bad as it might have been. I was not looking directly at the prism from which the beam had reflected, so the retinal damage is not in the fovea. The beam struck my retina between the fovea and the optic nerve, missing the optic nerve by about three millimeters. Had the focused beam struck the fovea, I should have sustained a blind spot in the center of my field of visions. Had it struck the optic nerve, I probably would have lost sight of that eye.

The beam did strike so close to the optic nerve, however, that it severed nerve-fiber bundles radiating from the optic nerve. This has resulted in a crescent-shaped blind spot many times the size of the lesion. [...] The effect of the large blind area is much like having a finger placed over one's filed of vision. Also, I still have numerous floating objects in the field of view of my damaged eye, although the blood streamers have disappeared. These `floaters' are more a daily hindrance than the blind areas, because the brain tries to integrate out the blind area when the undamaged eye is open. There is also recurrent pain in the eye, especially when have been reading too long or when I get tired.

The moral of all this is to be careful and wear protective goggles when using high power lasers. The temporary discomfort is far less than the permanent discomfort of eye damage. The type of reflected beam which injured me also is diffraction gratings, and by all beamsplitters or polarizers used in optical chains.

The victim of Case History No. 1 explained that protective goggles were not being worn at the time, although they were available in the laboratory. He also std, "As any experienced laser researcher knows, goggles not only cause tunnel vision and become fogged, they become very uncomfortable after several hours in the laboratory." This statement substantiates the author's contention that management of eye prction must include knowledge of all types of eyewear and not accept the myth that heavy, uncomfortable goggles must be worn to ensure safety.
----

Goggles only work when you know the frequency you are expecting. Even the US military does not yet have an effective way to prevent laser blinding weapons. The only known method is indirect viewing via a TV camera. Work continues towards an exotic non-linearly responsive material which will automatically darken before the damage threshold is reached. It might be possible to modify an electronic welders mask with LCD shutter, however, my tests have shown that they would be ineffective against a high pulsed power single shot which passed the damage threshold in less than, say, 0.05 seconds. This is because they react slowly compared to a laser pulse with a sharp rise time, whereas a welding flash has a far lower energy for a much longer time, so you see the very beginning of the flash, before the screen darkens.

[nbk2000]

"Frequency agile" is the term for multi-spectral laser weapons.

There's supposedly a patent for an mercury coated ablative mirror that, when exposed to a sufficiently intense pulse of energy that's capable of blinding, vaporizes the coating off of the mirror, which absorbs and diffuses the beam enough to prevent more than minor flash-blinding. I saw mention of it in a military PDF about these weapons.

Not ideal, of course, but better than hearing your eyeball go "POP!" and feeling it dribbling down your face. :eek:

[DimmuJesus]

The whole concept of a neural disruptor is intriguing. Using if as a weapon or to rob a bank has much potential. It would seem that something as simple as an unassuming baseball cap lined with a thin sheet of copper would make a good defense.

What really interests me is the idea of using this technology as an enhancer, as Arthis mentioned. You could use it to stimulate the brain to heighten your senses, reduce fear, or even trigger the brain to release controlled amounts of adrenaline when needed. This could increase speed, strength, and alertness.

[Jacks Complete]

NBK, not quite. Frequency agile means that you can tune the laser output to a desired frequency. For example, a Ti:Sapphire laser is frequency agile, as is an FEL (Free Electron Laser). They are not multi-spectral in that they output just one frequency at a time, and are tuned by changing the laser cavity length, the optics or some other parameter. Argon ion is a multi-spectral laser, as is the Helium-Neon. Both of these output multiple wavelengths, and so one of them can be tuned to output what you want from the selection. Hence HeNe lasers in IR, red, orange, yellow and green. Normally the "big" one is the Krypton/Argon ion "whitelight" gas mix, which, when used with wideband mirrors gives out what appears to the eye to be a white beam. It is actually composed of several frequencies at the same time, and so is "multi-spectral".

This would make a simple coloured filter type of protection totally useless, as it would have to be like a welders mask!

That mercury mirror sounds quite neat.

DimmuJesus, there is an article in New Scientist from the other week about that.
I found this one, too.
---

The field workers

New Scientist vol 165 issue 2224 - 06 February 2000, page 36


Aim a magnet at a healthy brain, and the weirdest things happen. But could it finally tell us which bit does what, wonders Peter Collins


CHARLES EPSTEIN, a neurologist from Emory University in Atlanta, Georgia, was recently party to a remarkable experiment that quite literally left his colleagues struggling for words. Epstein asked fellow researcher James Lah to start counting out loud, while he held a small magnetic coil, roughly the size of a mobile phone, against Lah's forehead.

"One, two, three," said Lah, quite happily. But when Epstein flicked on the power to the coil, Lah rapidly lost the power of speech. All that he could manage was "fo..., fo..., fo...". When Epstein cut the power again, Lah continued, "four, five, six," as if nothing had happened.

"The sensation really was quite weird," says Lah. He claims that he could think about the words he wanted to say, but just couldn't get them out. He says it was a frustrating feeling similar to when your arm or leg falls asleep, except that this time it was the muscles of his face that failed to respond properly. Of course, Epstein's demonstration is more than just a neat party trick. In fact, he had momentarily interrupted the workings of a part of Lah's brain, by stimulating it with a magnetic pulse.

The technique he used is called transcranial magnetic stimulation, or TMS. While scientists have been trying to alter brain activity with magnetic and electrical fields for more than a century, the modern age of TMS research began only around 15 years ago. TMS was developed as a technique to stimulate the brain's motor circuits to test their integrity after damage to the brain or spinal cord. But within the past ten years researchers have started using it to look at how the brain controls other types of behaviour. TMS has also been tried out as a potential treatment for depression. So it is now making a big impression not just on Lah's ability to count out loud, but in neuroscience labs all around the world.

It is the ability of TMS to change the activity in small parts of the brain for short periods of time that is so exciting cognitive scientists. Depending on how it is used, TMS can slow down or even switch off parts of the brain temporarily. With a tweak to the settings it can stimulate brain activity instead. There are even some tantalising clues that TMS could enhance learning and perception. And the technique is giving researchers the first real proof that activity in particular parts of the brain gives rise to particular sensations or behaviours—a vital step in their quest to understand how the brain works and how it gives rise to the mind.

The basic idea behind TMS is simple. A short-lived electrical current in a figure-of-8 stimulating coil, produces an intense magnetic field, about 200 times the strength of the average fridge magnet, within about one-thousandth of a second. This rapid switch induces an electric field in a small region which can extend a couple of centimetres down from the surface of the brain, making the neurons there fire abnormally. Depending on the firing patterns, this can boost activity, or effectively scramble or jam the signal from that area of the brain. The field intensity, the shape of the stimulating coil and the rate of the pulses (anything from a single pulse to 50 each second) determine how widespread and how intense the effect is.

Brief interruption

Whereas prompting the brain into action might seem an exciting prospect, remarkably neuroscientists are also keen to interrupt the workings of the brain. This is because some of the most enlightening information about how the brain works has come from patients with brain damage, caused by accidents, strokes or surgical removal of brain tumours. By studying these patients, you can see what abilities are lost along with a particular brain region, and get a reasonable idea about where memories are stored, which areas of the brain are important for vision, language, movement and so on. But such patients are in fairly short supply, and no two patients are identical. Moreover, this type of brain damage is rarely confined to small and functionally discrete areas of the brain, so it's not easy to pin down the functions of different brain locations very precisely.

Brain scanning techniques have vastly improved our knowledge of the functions of different brain regions, by showing which areas are active at a particular time during a particular task. However, as Stephen Kosslyn, a psychologist at Harvard University in Cambridge, Massachusetts, points out: "Neuroimaging techniques only establish a correlation. A given set of brain areas are activated when someone performs a given task. But we all know that correlation does not show causation." Kosslyn points out that TMS provides a stronger link between cause and effect, by showing exactly what happens when you interrupt brain activity in a particular area. Researchers no longer have to wait for a patient to turn up in the clinic to verify their functional brain maps. With TMS they can create "virtual patients".

Kosslyn and his colleagues showed how this could work last year. He has a long-standing interest in visual imagery, and was keen to know whether creating a mental picture of an object uses the same brain circuitry as actually looking at it. Brain scans and brain-damaged patients have shown that some areas of cortex at the back of the brain would normally be active during both activities—but which are vital?

Kosslyn used TMS to block activity in a small area of the visual cortex, called area 17, while he asked people to look at two images and compare properties such as the relative lengths of stripes within the images. Stimulating area 17 with TMS prevented people who were looking at the images from making rapid comparisons. Interestingly, when Kosslyn asked his volunteers to compare the stripes in their mind's eye, again they had difficulty making the comparisons when area 17 was stimulated. So area 17 seems to be crucial for both seeing and imagining.

Vincent Walsh, a Royal Society Research Fellow working at the Experimental Psychology Department at Oxford University, and his colleagues, have also used TMS to study the visual system, but have concentrated on motion perception. Clinical and experimental studies suggest that another visual area at the back of the brain, V5, is involved in motion processing. When Walsh stimulated V5 using TMS he disrupted people's ability to spot a small moving X in an array of stationary Xs. But he also found a more interesting effect. By blocking motion processing in V5, he could make it easier to spot a target defined by its shape or colour, when motion of the target or the other stimuli in the array was irrelevant and distracting. "This may indicate that some areas of the brain normally compete with each other for limited resources," says Walsh. "Disrupting the function in one area may `free-up' processing in another area, leading to the improved performance."

No compensation

Similar effects are difficult to spot in patients with real brain injury, perhaps because over time the brain reorganises a little to compensate for the damage. For Walsh this reveals the true value of TMS. "The key point here is that the `virtual lesions' induced by TMS last only a few milliseconds, and this doesn't give the brain time to reorganise."

There are other tantalising signs that TMS could improve brain function. Alvaro Pascual-Leone and his colleagues from the Beth Israel Deaconess Medical Center in Boston have tested the effect of TMS on learning, in this case learning a simple sequence of key presses guided by the position of an asterisk on a computer screen. In a series of trials the asterisk dances across the screen and the subject taps out the corresponding sequence of key presses as quickly as possible. "We have known for a long time that subjects get faster if, unbeknown to them, an ordered sequence is repeatedly presented," says Pascual-Leone. But the researchers found that TMS could speed up reaction times even more. "What is novel and potentially very exciting is that by stimulating the motor cortex at particular frequencies we were able to speed up the learning of this task," says Pascual-Leone.

And it's not just motor learning that could benefit from a burst of magnetic pulses. Ralph Topper from Aachen Technical University in Germany and his colleagues seem to have enhanced peoples' ability to name objects appearing as line drawings on a computer screen. Volunteers named the objects faster if they had been exposed to a pulse of TMS over the language area known as Wernicke's area, on the left side of the brain, just before they saw each of the pictures.

To Pascual-Leone, these findings suggest that TMS might one day enhance standard rehabilitation techniques for stroke cases and brain damage. TMS could potentially jump-start or "warm up" brain circuits to help them take over the function of the damaged region. "The adult brain is turning out to be more flexible than we initially thought—we need to find ways to encourage and control this flexibility," says Pascual-Leone. "TMS might just be such an approach."

It looks as though TMS might help lift some people out of their depression by reviving neural activity in underactive circuits (New Scientist, 5 August 1995, p 24). Early tests showed promising improvements in the mood of a small number of patients. And the most recent results suggest that TMS might help patients who have not responded to standard drug treatments. In a large trial of TMS for treating depression, under way in Boston, patients with major depressive disorder have been given an intensive course of TMS for 30 minutes every weekday for two weeks, then monitored for 3 months afterwards.

So far, the treatment has produced marked improvements in the standard clinical rating scales for depression in more than half of the patients, after stimulation of the left prefrontal cortex—an area at the front of the brain, which seems to be underactive in depressed patients. This is a remarkable number considering the severity of their condition and their lack of response to three different classes of antidepressant drugs. Many of these patients had been in hospital as a result of their depression and some had attempted suicide in the past.

"The most striking finding is that the beneficial effects can last for up to six months after TMS," says Pascual-Leone. In some patients, they have been able to keep symptoms at bay simply by giving a further course of TMS every three months, avoiding all other forms of medication. Preliminary results from a brain scanning study suggest that this improvement may actually represent a return to normal brain metabolism in this left prefrontal area, although Pascual-Leone and Walsh are not yet convinced. Ray Dolan, a psychiatrist at the Functional Imaging Laboratory in London points out that the difficulty with TMS, like electro-convulsive therapy (ECT), is that there is no clear biological mechanism to explain how it might provide an effective treatment for depression. We just don't know how stimulating these brain areas affects mood. "Nobody seriously thinks that the regions targeted by TMS in these studies are directly involved in mood regulation," says Dolan. And even if they were, how do the benefits persist for a matter of months?

But perhaps not surprisingly, researchers around the world are sufficiently heartened by the potential of TMS to start trying it out on other neuropsychiatric conditions such as obsessive-compulsive disorder, mania, post-traumatic stress disorder and schizophrenia.

Walsh predicts that within 20 years, every psychology department will have its own TMS machine. At £20 000 a set, it is a relatively cheap way of studying the brain, considering that a functional MRI brain scanner costs several million pounds. But before this happens, some feel that we should pause and think. There are ethical and safety issues that need to be considered. After all, TMS works by scrambling neural activity. Indeed, there were a handful of early reports of epileptic seizures after TMS, but these were all in people who had a previous history or family history of epilepsy or were the result of high intensity TMS used in the early development of the technique.

The TMS community has tackled this issue head-on by devising a set of guidelines for how TMS should be used. Walsh puts it like this: "Obviously one has to be careful with any experimental technique, but the TMS community is very aware of this and has published a set of ethical and safety guidelines that are designed to prevent any problems. They appear to work very well and experiments are now always carried out at the lowest possible intensities and are rightly subject to local ethical committee approval."

Pascual-Leone thinks we should also consider the problems associated with the possible recreational use of TMS. "Given the non-invasive nature of this technique and its apparent safety, together with the possibility of effects on mood, there is a potential for unauthorised research or even recreational use," he says. He notes that humans are prone to ridiculous extremes. But the last thing we want is a Delgadoian vision of a psycho-civilised society, he says. Delgado stimulated the brain to induce and block rage in experimental animals around 30 years ago and speculated wildly about how this might be used to control society. "While there is no evidence that TMS can be used in any of these ways, society must ultimately have a stake in how this technique is used."

Peter Collins
---
The genius machine

New Scientist vol 182 issue 2441 - 03 April 2004, page 30


No one is quite sure where creativity comes from, but that doesn't worry Allan Snyder. He says he knows how to turn it on at the flick of a switch. Helen Phillips investigates


"TAKING RISKS," says Allan Snyder, "that's one of the main things that drives me." All the more amazing, then, that so many people willingly don his specially designed headpiece so he can zap their brains with strong magnetic pulses in a bid to turn them, temporarily, into autistic savants.

Snyder, director of Australia's Centre for the Mind, wouldn't put it quite like that. He'd say he was switching off higher brain functions in an attempt to mimic certain symptoms of mental illness. But it boils down to the same thing. Snyder wanted to see whether he could turn everyman into Rain Man.

Why, you might ask, would he want to do that? Well, he explains, perhaps if he gets the conditions just right, his magnetic mind-zapper might act as a creativity machine, revealing an inner genius his subjects didn't even know they possessed.

Given Snyder's obvious eccentricity and self-confessed love of risk, you might be forgiven for running a mile rather than have him mess with your mind. But he is perfectly serious. Take a moment to look over his numerous awards and fellowships, his thriving research centres at the University of Sydney and the Australian National University in Canberra, not to mention his record of attracting the likes of the Dalai Lama and Nelson Mandela to his conferences, and you feel perhaps you ought to hear him out. Once he starts explaining himself, it becomes hard to see where eccentricity ends and creative genius begins. And maybe that's the point.

Madness has long been linked with creativity. Van Gogh, Edgar Allan Poe, Tchaikovsky and John Nash all trod a fine line between the two. But it wasn't psychotic or manic genius that got Snyder thinking. It was autistic savants - severely impaired people with one or more amazing mental skills, perhaps in drawing, music, sculpture or language. These talents are all the more striking because they often occur in people whose intelligence is otherwise very limited.

Despite popular belief, autism is seldom linked with amazing skills. For every autistic savant there are maybe 10 more people with autism who do not have a special skill. And roughly half of all savants are not autistic, but have some other form of mental illness, brain damage or retardation. But the fact that savants exist at all gave Snyder a bright idea. "My research is directed at the belief that you can switch on extraordinary skills by switching off part of the brain," he explains.

Psychologists have long been fascinated by savant skills. The orthodox view is that these "islands of genius" result from obsessive use of what little mental capacity is spared by the illness. But Snyder disagrees. He thinks we all have amazing skills, but they are concealed within our subconscious. Autism, he believes, causes some part of our brain's normal function to be lost, sometimes allowing the savant skills to shine through.

The main reason for thinking savant skills are hidden within everyone is that they can appear spontaneously after someone has suffered brain damage. One case in the literature, for example, documents how a child suddenly acquired spectacular calendar -calculating skills and an extraordinary memory for days, dates and music following an injury to the left side of the head at age 10. Another famous case is Alonzo Clemons, who developed a striking talent for animal sculpture following a childhood head injury.

Savants are also found among people with a rare neurodegenerative condition called frontotemporal dementia. In this disease, people - usually in their 50s - gradually lose their inhibitions and mental faculties as part of the brain beneath their temples withers away. Bruce Miller, a neurologist at the University of California, Los Angeles, who is an expert on the disease, has documented a handful of patients who developed artistic skills as their illness advanced. One patient with no prior interest in art took up drawing at the age of 53, producing vivid childhood scenes from memory (Neurology, vol 51, p 978).

The art produced by these people is distinctly savant-like, says Snyder, in that it consists of realistic scenes or memories rather than expressionistic or creative imagery. But what struck Snyder most was Miller's discovery that his patients all had damage in the same area of the brain, the left frontotemporal lobe. Previous studies have suggested that the majority of autistic savants have left-sided damage, and Miller himself has studied an autistic patient with damage in the left frontotemporal lobe. What's more, the people who became savants after a head injury also had damage on the left side.

One person who became a calendar-calculating savant after a head injury is now having his brain scanned in an attempt to pin down how his skills developed. But however it happened, the spontaneous and sudden appearance of remarkable mental abilities means they cannot be the result of training or obsessive practice, thinks Snyder. The skills must have been there to start with. "The people who possess these unusual skills do so because they have brain damage," he says. "Our theory is that the brain damage made them access something that we all have."

But what might that be? Psychologists have long known that a large proportion of brain activity occurs without our knowledge, and that only a small amount ever reaches our conscious awareness. Snyder's version of this model is that your unconscious brain extracts all the raw sensory details about the world around you - the tones and pitches, lines, light and shadow. This information is far more than we can deal with, he believes. But it is where we experience the world "as it really is".

Except most people never see this version of events. Our unconscious mind takes the flood of information and simplifies and categorises it into manageable and useful packages. Where it sees lines and patterns of dark and shade, our conscious mind might know it is a horse. We know that, because our brain has learned all about horses, has experienced what makes something a horse rather than a dog or a table, and has formed a concept and a mental image. It's a very efficient way for our minds to work. It allows us to spot things quickly, to name them and communicate the ideas. The mind also learns how these things might behave, so that we can make predictions about the world and devise rules about how to act appropriately. Snyder calls these various ways of extracting meaning from the raw data "mindsets".

In Snyder's view, what savants lack is mindsets. They experience only raw sensory information, and their precise drawings are a reflection of that. The reason most people can't draw like that is because their mindsets get in the way. Once the brain forms a concept, it inhibits the conscious mind from becoming aware of the details that created that concept in the first place. So instead of drawing what you see, you draw what you know.

Snyder and his colleague John Mitchell first went public with this idea about five years ago, only to be met with widespread scepticism (New Scientist, 9 October 1999, p 30). So they began trying to prove it, which is where the magnetic brain-zapper comes in.

It sounds drastic, but using magnetic pulses to switch brain activity off is routinely used in neurology departments and hospitals. Called transcranial magnetic stimulation, or TMS, it is used as a research tool to test for side effects of brain surgery, and to work out the function of parts of the brain. The idea is simple: place a strong magnetic field on your scalp and you halt electrical activity in the nearby part of your brain, just as placing a fridge magnet on a computer can stop the hard drive from working (see Graphic).

Snyder and his colleagues decided to focus TMS on Miller's area - the left frontotemporal lobe - in the hope that temporary and reversible damage to it would let savant skills shine through. Last year they tried it out, first on Snyder himself, then on 11 volunteers under experimental conditions. And late last year he published the initial results (Journal of Integrative Neuroscience, vol 2, p 149).

First the downside. Only four of the 11 volunteers responded to TMS. This, however, isn't all that unusual, says Niels Birbaumer from the Institute for Medical Psychology and Behavioural Neurobiology at the University of Tübingen in Germany. "In some people you get an effect, in some not, and in any case the effect is not very strong and that's typical for TMS results," he says. No one really knows why this is, but it probably has something to do with the fact that brain organisation varies widely from person to person.

In the four people who responded, however, TMS had some notable effects, Snyder says. First he looked at the subjects' drawing style before, during and after a 15-minute bout of TMS. He asked them to draw people from memory after briefly showing them photos, and animals from their imagination. It's hard to say that TMS made the subjects better at drawing, but it did seem to change their style (see Graphic). You might say the drawings were more natural. The effects lasted for 45 minutes or so, suggesting either that the TMS had some lingering effects, or that subjects learned a new way to do things. Three of the four people who responded also reported altered states of consciousness, saying they became more aware of detail. Other subjects said they felt slightly high.

Snyder also wanted a more objective test, so he asked his subjects to proofread phrases with a non-obvious mistake. Without TMS everybody missed the errors, but with TMS two subjects were more likely to see them. One improved from zero to a 70 per cent success rate, the other from zero to 50 per cent. Snyder claims that this is evidence that TMS makes the subjects see the world the way it really is. "Like autistic savants, they are much more literal," he says.

Snyder is also working on a set of tests for mathematical skills, looking at prime number generation and calendar-calculating skills, and also musical skills.

Other researchers have results that back Snyder up. Psychologist Robyn Young and her colleagues at Flinders University in Adelaide, South Australia, initially sceptical of Snyder's theory, looked at a wider range of skills under TMS. She asked volunteers to recall lists of names, addresses and telephone numbers, reproduce pictures they had been shown for just a short time, judge musical pitches as higher, lower or the same as a test pitch, and spot the primes in a long list of numbers. Five out of her 17 subjects showed some improvements. These were not miraculous, she says, though one person, strikingly, improved across the board. She hopes to have her findings accepted for publication soon.

If Snyder and his team are right and we all have hidden, savant-like skills, he suggests some interesting implications. He predicts that TMS could grant us, at least temporarily, access to savant-like skills such as perfect pitch, improved memory or the ability to learn a new language without an accent. Snyder's favourite idea, however, is that he could use a TMS machine as a "thinking cap" to boost creativity.

This is quite a claim. Psychologists cannot agree what creativity is nor where it comes from, but the one thing they would all agree on is that savant skills are anything but. They might look creative but are really just an elaborate form of copying, says John Geake, who studies creativity at Oxford Brooks University in the UK. A savant pianist might reproduce an entire piece having heard it only once, but would be unable to compose or improvise. A savant artist, meanwhile, might draw a building in accurate detail from memory but the drawing would lack interpretation or originality.

Snyder doesn't dispute this. "It's clear that savant skills are pure mimicry," he says, "almost the opposite of creation." But he argues that there is a link between savantism and creativity. Being creative, he explains, is all about linking seemingly disparate ideas in a new way. Perhaps, then, a brief look at the world as a savant sees it, shorn of mindsets, would help you make such links. Savants routinely operate without mindsets, so cannot use the experience creatively. But if a normal person could dip in and out of the savant's world, it might be a different story.

It's an idea Snyder and his team have only just launched into the world of neuroscience (Journal of Integrative Neuroscience, vol 3, p 19). And the initial responses are, perhaps not surprisingly, a little sceptical. Birbaumer, though generally agreeing with Snyder that our subconscious brain has a lot in common with autistic savants, does not buy his theory about creativity. "It's speculative and far-fetched," he says. It's quite a leap from showing glimmers of savant-like skills within us all to placing them at the heart of a grand theory of creativity - especially as Snyder has not yet shown that TMS can deliver a creative boost.

One major objection is that there are other theories about creativity, long developed in the psychological literature, which Snyder is ignoring. Brain-imaging work, for example, has shown that the hippocampus, a memory structure deep in the brain, is active at that moment of insight when people solve riddles (Hippocampus, vol 13, p 316). This is not a brain area that Snyder has considered important, nor is it accessible to TMS because it lies too deep. What is more, Geake, along with Peter Hansen and others at the University of Oxford, has suggested that creativity relies heavily on mindsets. They found that a large working memory correlates with increased creativity. The more information you can juggle the more likely you are to make creative connections.

But other established ideas seem to chime with Snyder's view. Jordon Peterson, a psychologist at the University of Toronto, Ontario, says that creativity comes when people break out of their perceptual habits and see a new way of doing things. Psychologists talk about us having "frames" or perceptions about the world, echoing Snyder's mindsets. Although Peterson has different ideas to Snyder about how people form a new view, he agrees that creative people can switch between frames and make new ones more readily.

And the well-established link between mental illness and creativity makes sense in Snyder's view of things too. Perhaps certain mental illnesses are caused by inadvertent access to our normally subconscious view of the world, he suggests. Losing access to your conceptual mind may cause many problems, but a side effect might be an insightful glimpse of the world as it really is.

There may be a multitude of existing theories about what makes a brain creative. But none of them has yet been proved. Without testing, who can say what is at the heart of creativity: memory capacity, specialisations in brain areas, differences in thinking style?

Not everyone will be convinced by Snyder's idea about what makes a mind creative. But it's brave and original, and he has come up with something that can be tested. It might be completely crazy. But then again, it might just be the most amazingly creative insight.

[nbk2000]

I used the term "Multi-spectral" to indicate that it (whatever it is) is capable of more than one frequency of the spectrum (visible or otherwise). I didn't specify the means, nor that there can be several emission spectra because I'm assuming that people would understand it correctly the first time.

Obviously I was wrong.

You're trying to explain the concept of multi-spectral laser emission to a person who was studying about lasers back in the days when all lasers where tubes, and there were no such things as diode lasers to make things simple.

Thank you for clearing my ignorance on the basics. :rolleyes:

[Jacks Complete]

nbk, not to clear up your confusion, then, but to clear other people's.

:o

[nbk2000]

I encourage people to learn to fish on their own, rather than handing them the fish. It makes them self-sufficent. And self-sufficient people live longer. ;)