How magnets affect the human brain

Put a powerful magnet against the side of your head and it can interfere with the neurons working underneath. The technique is being used to treat severe depression, but it can also produce some nifty party tricks. In this video, a magnet held to left side of New Scientist editor Roger Highfield's skull interrupts his ability to speak a nursery rhyme. But when Highfield sings the same rhyme, there's no effect. That's because the neurons that control speech and the neurons that control singing are in separate parts of the brain. The magnet disabled Highfield's speech centers, but left his ability to sing untouched.


  1. Before trying this out at Hackspace can anyone confirm whether it is, in fact, seriously dangerous? Not sure I’d want anyone futzing with my neurons…

    1. Exactly. I put a huge magnet on my TV screen a long time ago and it turned the picture green. Took two weeks for it to get back to normal. I’d think twice about putting one against my head. Fucking magnets, man.

      1. It’s the result of a neuro-viral marketing technique employed by the geniuses at Motherfucking Insane Clown Posse Enterprises, Inc.

  2. The two circular electromagnets create a very strong field at a focal point inside the brain. When this field gets very strong at a certain point, the normal ion flow in the brain’s neurons gets screwy, impairing the normal propagation of action potentials and synaptic firing.

    Since it’s messing up the language processing center, but he can still move his mouth properly I’d guess at it being Wernicke’s Area, which is used in coming up with words in speech.

    This is all just a very informed guess though!

  3. OK, why don’t people getting MRI’s get all sorts of weird effects then? I call shenanigans – this is actually sending current when the clicking is going on (in the beginning it did say “electrical and magnetic” and at 3:17 he says they do current now, and will pass current in the future but without the clicking that it makes now). I am seeing this as a reinvention electro shock therapy that you can do at home. The “magnetic” portion smells like marketing to me.

  4. Quick note to clarify something which doesn’t come across in the post (and isn’t clear in the video):

    This is transcranial magnetic stimulation (TMS). Holding a magnet (even and industrial strength magnet) to your head won’t produce those effects. An electrical current is run through the coil, which generates a magnetic pulse that runs perpendicular to the coil and into your brain. That magnetic pulse then generates an electrical field in the brain (which runs parallel to the coil) which is what affects the underlying neurons.

    (On an entirely trivial point, I think I’ve been in that room, both as experimenter and participant.)

    @cholten99: Define “seriously dangerous.” I’ve done more than a few TMS studies, and have suffered no ill effects. As it showed in the video, most of the time you get a very brief change in perception/behavior. Different kinds of stimulation (high-frequency & lower intensity over several minutes) produce longer lasting effects, but even those only last for something on the order of an hour. In labs where people are careful and know what they are doing, it is entirely safe.

    That said, our policy was to exclude anyone who had even a family history of epilepsy, so as to avoid the risk of causing a seizure. We would also screen for other things (alcohol use or sleep deprivation in the last 24 hours, over-caffeination) just to be on the safe side. Also, there are upper limits on the output of the equipment (which, by the way, costs tens of thousands of dollars) to prevent harm being done. If someone where to be foolish enough (and it would be VERY foolish) to try this with some home-made kit, I’d honestly be more worried about electrocution and burns than neuron futzing.

    1. This is interesting Stuff, I am interested if you know of studies are being done with static electricity too? There were some articles a while back where they said they thought ball lightening wasn’t a real world phenominon but instead a halucination caused by ambient static electricity during an electrical storm.

    2. For those of us foolish/bold enough to be intrigued by the idea of a home-made TMS machine, there is the Open rTMS project:

      The project is still very much in the early stages and I’m not sure how much activity there is on the mailing lists, but I do check in on the page every once in a while.

  5. Well, that’s what you get for venturing into a basement lab-or-atory… Thank you very much, Doktor, but I’ll wait outside with my torch.

  6. I think it’s really important to note that these effects are not due to the magnets themselves. They are due to quickly changing magnetic fields. If you just held up a magnet to the head, these effects would never happen. It is only because a quickly changing magnetic field induces a current (the current can disrupt neural activity) that these work.

    I worry people will get the idea that those magnetic healing bracelets could actually do something.

    Maggie, you’re usually right on and don’t promulgate quackery. Thank you.

  7. Does anyone know if this effect is apparent with MRI, especially fMRI, where the brain itself is being closely scanned. It sounds at first glance as if it might be: you have a multi-Tesla fixed magnet, a variable magnetic field component and a kilowatt RF generator … That should be sufficient to induce transient currents in the tissue under observation …

    1. Great question. MRI systems are carefully calibrated to avoid these effects. In fact, the gradient field of an MRI is very similar in strength and rate of change to the fields used in TMS. There is a fair amount of published literature on MRI systems and how to avoid inducing depolarization.

  8. @daen yes, similar effects are seen in MRI, but only occasionally, and with peripheral nerves, like the arms or legs.
    I suggest looking up peripheral nerve stimulation (PNS) in MRI.

  9. Thanks, HopelessSavage and tesselater, for the clarification.

    Faraday himself first identified the effect of the changing magnetic fields and tried it on himself; basically he put his head inside a big coil, switched a current on and off, and briefly induced vertigo, proving that researchers of yore were the Evel Kneivels of their day.

    I’ve done research on TMS, and I’ve volunteered as a control subject in a few studies, but the safety of TMS was well-documented before I let anyone put that device near my head.

    If you want to get picky, you should differentiate between single pulse and repetitive TMS. The latter is looked at more for treatment; but there is a slight increase in risk of seizure for people already diagnosed with epilepsy.

    And, tesselater, I’ve already seen a bunch of patients wearing magnets based on articles they’ve read on TMS. But then, I’ve also had to dissuade patients from spending hundreds or thousands of dollars on electrical gadgets to “realign their DNA,” hologram stickers to treat arthritis, and other such foolery. I quote from the science Bible: “There will always be the quacks.”

  10. Interestingly, I was just watching a program where electromagnetic stimulation was being used to treat someone with Asperger syndrome.

  11. What I found interesting was that apparently the subject was repeating the beginning of the word in time with the clicks. Is the brain restarting the word after stimulation is removed, or does stimulation result in restarting the current word?

  12. TMS can induce a brain crash, aka seizure.

    I’m surprised that nobody has referenced it yet, but apparently the ‘I’m really happy’ part of the brain is located out of the range of the current TMS technology. Otherwise we’d have the wireless version of Niven’s wireheads.

    1. “I’m surprised that nobody has referenced it yet, but apparently the ‘I’m really happy’ part of the brain is located out of the range of the current TMS technology. Otherwise we’d have the wireless version of Niven’s wireheads.”

      neostim is working on it.

  13. I’m a little freaked out that this is called a “nifty party trick.” I cringe at all the upcoming YouTube videos.

  14. (A quick caveat to my previous and current comments: I am a cognitive neuroscience researcher and have been involved in TMS studies. I’ve also been a subject in TMS experiments, so I know what it feels like. TMS is not my primary method, so I would not consider myself an expert. Also, I know very little about language research.)

    @Robert: That actually gets at the heart of what happens both w/ TMS in general and with language production specifically, and I bet there are multiple labs working on it, if there aren’t publications out already. Even though TMS often gets described as creating a “temporary lession” or causing “deactivation,” it is not entirely clear what is happening at the neural level. Certainly, it is not obvious that these pulses shut off neurons, though again what is actually happening remains an open question. If I were to hazard a guess (see caveat above), I might think that the pulses in this case disrupt the normal firing patterns in the effected regions, which could include preventing feedback indicating that the word which the person was trying to produce had been produced. This could cause the restarting observed in the video. Hopefully someone more knowledgeable re: language production can correct me if I’m wrong.

    @RedShirt77 Couldn’t say anything about static electricity. I imagine it would be pretty difficult to get controlled, localized effects with it, though. People are also using direct current stimulation in a similar fashion to TMS (know very little about this). Also, you can use TMS to produce a visual percept, called a phosphene, which looks like a flash of light. Depending on where and under what conditions you stimulate, it’s possible for the phosphene to move or have a certain color to it (maybe this is related to the ball lightning phenomenon you mention? couldn’t say for sure). As cool as that may sound, having seen them I can say that the experience is pretty underwhelming.

    @Peaked I could see that being very useful for new labs w/ limited funds just getting started. I wonder where they are based and what sort of regulatory clearance they have, since I believe TMS falls under FDA supervision.

  15. I worry this will lead to a “noninvasive lobotomy” with as wide an area as it seems to be applied to, relative to what’s ostensibly the target area. My fear is that it will be treated like a microwave, with people imagining it works from the inside out and ignoring the effect on the brain tissue it penetrate to get to the target area.

  16. Physical chemist here. Static electricity is an electrical charge gradient, i.e. an electrical field. Putting an electrical field across your head is not a good idea, given that it’s a conductor. Your brain works with electric charge differences (action potentials). They also power every cell in your body (mitochondrial potentials). The oscillating magnetic fields are affecting your brain here by inducing eddy currents in the ions (charged atoms and molecules) which are used for your brain function.

    As Toff implied, given all the ‘magnet’ quackery that’s out there, I think it’s important to underline that this is NOT “how magnets affect the human brain” but “how a strong **oscillating** magnetic field affects the human brain”. Static fields (i.e. from a permanent magnet, an MRI machine, or the Earth’s own field for that matter) don’t have the same effect.

    1. @Alex_M: But MRI machines don’t just have a static magnetic field – they also have magnetic gradient coils mapping the x,y and z axes. Slight imperfections in the manufacture of those coils can result in precisely the rapidly oscillating field strengths that TMS results from, right?

  17. Interesting about the subject being able to sing the nursery rhyme. I remember reading about a sea captain who had a crew mate who stuttered. The crew mate was trying to tell the captain about an impending disaster, but couldn’t get it out until the cap’n bellowed, “Sing it, man!”

    1. in leroy thomas’s “taxi, take me to the trail ride” he tells a story about how he got so drunk he started stuttering & couldn’t tell the driver where he wanted to go, so he sang it:-)

  18. No surprise there. I had already read how MRIs were being used to induce stroke like symptoms in a study. And already tried taping magnets over the pain of a migraine to see if they helped. They didn’t but I could tell my mind was fuzzier. However what they do help is arthritis. Tape some very strong tiny ones to your knees and they will reduce the pain. I guess they interfere with the transmission of pain impulses.

    But the more I think about it I more I don’t like, say, the CIA knowing how to induce brain freeze in a person. I wonder who is funding this.

  19. You put a magnet next to your head every time you hold a cell phone there. When an electronic device is powered it emits a thing called an electromagnetic field. The magnetic portion of that works just like a magnet. Don’t believe me? Try sucking some iron out of some sand with a magnet. Then scrape the iron off of the magnet on to a piece of paper. Scatter the iron around so it’s covering the sheet of paper. Then turn your cell phone on and move it under the paper. You’ll see the iron dance.

    1. You’re probably seeing the effect of the permanent magnet in the phone’s vibrator. I doubt the electromagnetic effects of microwaves on iron filings would be noticeable.

  20. Dumb question, but if the effects of the strong magnetic pulse creates a stutter (however brief), is it possible that a complementary/orthogonal research effort could be spawned to see how possibly using a similar approach might help chronic stutterers?

    1. It depends on the underlying cause of the stuttering. As Prof. Walsh mentioned in the video, many groups are working on using TMS for long-term therapeutic purposes, though this research is still in the early stages, and would involve more than just a split-second of stimulation.

      I think that the trick would be 1st pinpointing a region (or even a set of regions) in the brain responsible for the stuttering, and then determining whether the problem is due to some sort of disordered neural firing that would be altered by application of TMS in some form. Looking at the link below which gives a brief clinical description of stuttering, that seems unlikely, but certainly not impossible.

      1. @rauscha, Wernicke’s area is actually the locus for comprehension of language. Broca’s area is the part concerned with the production of language. (Click here for a visualization.) You may have them confused because when a lesion affects Wernicke’s area, a person’s language comprehension can be damaged enough that they don’t understand their own output, and it becomes nonsensical without them being aware of it.

        @HopelessSavage, It’s hard to say whether this is actually related to stuttering or not. From what I know, nobody has associated any particular part of the brain with stuttering. Some people get some relief from delayed auditory feedback, where a microphone picks up their voice and plays it out an earphone speaker at a slight delay, suggesting that there’s a receptive feedback aspect to it. Some people don’t benefit from this at all, though, and the effect wears off for others.

        It’s too bad that it’s such a transient effect, because we could tell a lot more about what abilities were being disrupted that way. The reporter’s brief halt, and restarting of a couple of words, could be word-retrieval, language production, motor control interruption (probably not), stuff I can’t think of now, etc.

        Hmm. I was hoping I’d have more to contribute, but I think I’m out of my depth. This is all recall from school a year or two ago, and I’ve mostly been working with kids.

  21. Magnets do not afffect the brain. Rapidly changing magnetic fields can. The rate of change (dI/dT in the inductor) is what matters, not the absolute field strength. To get a high rate of change is easier when you have a longer time to do it in, this means higher field strengths. But it is a side effect, and not required technically. The coil shape matters and for brain stimulation it is usually two opposingly wound flat coils in the shape similar to a butterfly. The change in the magnetic field is proportional to the voltage induced across the dieletric (cell membrane) of a given neuronal axon.

    This induced voltage is what triggers the action potential. The rate at which action potentials are triggered can be used to increase the activity of a neutronal population, or decrease it. The ‘temporary leisions’ discussed are from firing a population so often that they are ‘worn out’. This is like the afterimage effect from looking at a bright light too long.

    So… pulsed electromagnets can affect your brain but magnets do not and can not. Static magnetic fields have no effect!

  22. This reminds me of the ‘nifty party tricks’ that folks used to do back in the early days of radioactivity.

    What could possibly go wrong?

    So thanks, but I’ll be waiting outside with KBert and a pitchfork.

  23. So all that stuff in the X-Men about Magneto controlling people’s brains is not too far off: albeit not via “manipulating the iron content of their blood” mechanism that is usually used.

  24. Show me a picture of a Nobel-prize-winning scientist sitting with a powerful magnet next to his head, and I’ll show you a man with issues.

    Great for erasing tapes though.

  25. this is not news. its been done for years in every major neurology course as a practical joke…..

  26. I’ve always wondered why I can “hear” and “recall” song lyrics in my mind (usually as part of the song), but as soon as I try to speak them, the lyrics vanish and I cannot recite them. It is like the singing lyrics reside in the same memory bank as that used to speak them and so are “erased” by any attempt to say them out loud. Even such a minor trait can be frustrating, I must say.

  27. There’s a character in a David Brin Uplift novel (I forget exactly which.) who has a traumatic brain injury and loses the ability to speak, but like the man here, can still sing songs.

  28. So the consensus among the comments is that “pulsed electromagnets can affect your brain but magnets do not and can not.” Good.
    (Resumes assembling chain mail-like helmet out of BuckyBalls.)

  29. They are saying we will need a lead helmet to not have scrambled brains after the incoming planet X with it’s huge size and crazy magnetic field come by and flip everything out. I felt a high level of EMF today, which is usually offset by my Q-link, but it’s not helping now. Not sure if it’s due to the scalar war going on with China and Russia and us, or if it’s something else going on. I know the animals are freaking out all over, and in our house, everyone is unexplicably agitated. See this a lot right now… Need to get some lead flashing or something for a helmet. Haha, the helmet, haha.

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