No surgery, no needles, just a coil pressed against your head and a brain that starts behaving differently.
The coil doctors hold against your scalp for this brain treatment is usually shaped like a butterfly, or which familiar number?
A figure eight The original coil was round, but the figure-eight design focuses the pulse on a smaller patch of brain just under the skull.
Zapping the brain with electricity through the scalp was painfully uncomfortable. So what invisible force did researcher Anthony Barker try instead?
Magnets A fast-changing magnetic field passes straight through the skull and creates a small electric current in the brain on the other side, and the first stable devices appeared in the mid-1980s.
In trials, many patients who got a fake version of the treatment with the power off still felt better. What famous effect explains that?
The placebo effect Researchers have long argued about how well the treatment really works, partly because people can often tell real pulses from fake ones by the twitching and discomfort.
Aim the magnetic pulse at the back of the head, where the brain handles eyesight, and what might people suddenly see?
Flashes of light Doctors call these phantom sparkles phosphenes, while pulses aimed at the brain's movement area make muscles twitch instead.
Today some veterans' hospitals use this magnetic headgear to treat what common mood disorder?
Depression The FDA has cleared dozens of these devices, and they are also used for chronic pain, OCD, and migraines.
