Using Magnets To Turn Off the Brain's Speech Center

An editor for the Telegraph, Roger Highfield, recently volunteered to allow a UK researcher to shut off the speech center of his brain with a high-powered magnetic pulse. Regular speech is controlled by a section of the brain called Broca's area. Once the precise location is determined in the subject, a magnetic pulse can temporarily disrupt speech without impairing other cognitive functions. The link contains a video in which you can watch Highfield stutter and twitch while attempting to recite a nursery rhyme. A later test shows that he's able to sing the rhyme without difficulty, since singing is controlled in a different part of the brain (as you may remember from Scott Adams' speech disorder). Researchers believe that the ability to stimulate or quell activity in specific areas of the brain may help in treating conditions like epilepsy and migraine headaches.

Courage...

[camg188]

That test subject had a lot of courage. No way is my brain getting zapped.

"turn-off" vs. disrupt

[G4from128k]

The notion that this pulse "turns-off" the targeted segment of the brain isn't correct. The pulse does NOT remove power from the brain or suppress neuronal firing. Instead, it disrupts coordinated firing of the neurons by inducing a spurious current in the neurons. Thus it is more like randomly applying a signal to the pins of a CPU than to cutting power or clipping pins.

I can't imagine that this pulse is very good for neuronal tissue in the short-term or long-term.

Transcranial magnetic stimulation

[moonbender]

The technology to do this is (apparently) called transcranial magnetic stimulation [wikipedia.org]. And even though it looks really freaky in the video with the twitching and everything, it appears to be safe as long as you don't suffer from epileps; in fact it's routinely done for therapeutic and diagnostic purposes.

I guess you still shouldn't try it at home, though.

This is called Transcranial Magnetic Stimulation

[Anonymous Coward]

This technology is called Transcranial Magnetic Stimulation [wikipedia.org] (or TMS).

Re:"turn-off" vs. disrupt

[Anonymous Coward]

Wrong. It would help if you weren't talking out of your ass and imagining how this device works. There are studies describing this technique which basically depolarizes neurons and depresses action potentials. In other words, it turns that area of the brain off by suppressing neurons from firing. Please do us all a favor and know exactly what you're talking about before chiming in.

Re:Non-ionizing EM

[FleaPlus]

Doesn't this imply that non-ionizing EM (for example, radio waves) may in fact disrupt brain function in some way? A high intensity pulse can apparently disrupt a major function.

Keep in mind that a typical TMS coil induces a current in brain neurons by generating a field which goes from 0 to 2 Tesla in about a tenth of a millisecond. Even then, the field is only effective at neural stimulation a centimeter or two away from the coil's focal point. I'm not too familiar with devices which generate non-ionizing EM, but I suspect you'd be hard-pressed to find something with those sorts of characteristics.

Re:This doesn't prove all that much...

[FleaPlus]

As long as the person is expecting their speech to be disturbed, and they can hear/feel the exact moment that the magnet is pulsing, the effect could be purely psychosomatic. They really need to test this on someone who's not expecting these effects. It may be ethically a bit strange, but it's the only true test.

There's actually a few different types of controls which are used experimentally. Here's what I can think of off the top of my head:

* use a sham coil that triggers the same sorts of clicking sound but doesn't actually stimulate anything

* more recently, a different type of sham coil [plosone.org] has been developed which allows you to modify current directions on-the-fly, allowing you to create the sound/sensation of scalp stimulation, but causes minimal stimulation in the brain region (disclaimer: this coil was devised by people from the same lab as me)

* you can switch which side of the brain you're stimulating on, and if the subject isn't familiar with neuroanatomy they'll be none the wiser. About midway down this page [wwnorton.com] there's a video of someone counting upwards, and it shows that even though there's a disruption when you stimulate Broca's area on the left side of the brain, no effect is observed when the symmetric area on the other side of the brain is stimulated.

Re:I wonder...

[David_Hart]

I'm not so sure about how good they are at bullet matching. I know that the TV shows (CSI, etc) and prosecuters want the public to believe that the bullet matching process is infallable. However, bullet matching, like so many other things, can be subjective and only explains a probability that the bullet was fired from a particular gun rather than proving it for a fact. Only when they develop and implement a tagging mechanism as the bullet is fired will we have a reliable system (http://www.laserfocusworld.com/display_article/162928/12/none/none/News/Laser-etching-may-help-investigators-ID-bullets). Even so, criminals and hackers would find their way around these systems by reprogramming the tags to match one owned by an innocent civilian.

David

Re:OK, guys. This needs to be explained

[fastest fascist]

Sadly, sexual orientation is not, to the best of my knowledge, something one can alter at will.

Here's a picture of the device used. . .

[Fantastic Lad]

Found a picture of the device used [typepad.com] to temporarily shut down the visual cortex.

Here's another story [healthyplace.com] on the technology. . .

TMS induces an electromagnetic current in the underlying cortical neurons, which may explain its therapeutic effects. Repetitive TMS, using varying frequencies and intensities, can increase or decrease excitability in the cortical area directly targeted by the stimulation. Recent studies combining TMS and neuroimaging techniques, such as magnetic resonance imaging, demonstrate that the effects of TMS are not limited to the cortex but spread to functionally related subcortical structures. This finding provides a basis for using TMS to treat the pathologic neural activity that may underlie neuropsychiatric illness.

The military has been aware of this stuff for decades. Look up "Dr. Delgado", (but beware the Rense-style garbage; such nonsense exists solely to look silly and make people drop the subject. Works like a charm unless you recognize it for what it is. Like planting a trouble-maker in a crowd to start a riot thus justifying brutality. Tried and true tactics.) In any case, with the long association of the military and telecom companies, (RF and EM technology comes from the same roots, development money and minds), it becomes impossible to assume that those involved with the introduction of cell phones on the world market had no idea of the secondary effects caused by the technology or what it could be used for. Indeed, it seems very likely that their introduction was predicated on these secondary effects. (Which would, from my perspective, make them the primary effects and easy communication the carrot).

But you must come to your own conclusions. Keep in mind, however, that choosing ignorance these days leads to a buzzy kind of bliss.

-FL