WHAT IT IS
Technically, it’s called a magnetoencephalograph with superconducting quantum interference devices. But most people — scientists included — just call it a MEG with SQUIDs.
WHAT IT DOES
It reads the magnetic fields generated by brain cells as they rocket electrical thought-signals through the brain. In short: I think, and it detects.
WHY THIS IS AWESOME
When a scientist or doctor needs to know exactly when and where something happens in the brain, this machine can’t be beat. It has better spatial resolution than an EEG, and is far faster than an fMRI, which relies on the leisurely eddies of blood flow to identify brain activity.
In fact, everything the MEG does, it does in real time. Were I epileptic or about to undergo brain surgery, the machine’s spatial and temporal resolution would make it the single best way — short of cracking open my skull — to detect where my seizures were beginning or where not to cut.
That means that as I sit in the chair for my scan — my head jammed into the inverted toilet-bowl cavity, fractions of an inch away from both a patchwork quilt of 306 sensors and the bath of liquid helium that keeps them just above absolute zero — it can see me process music, or move my hands, or even make a last-minute decision. (Although right now, since I’m only having a demonstration scan, it’s only watching me close my eyes, grind my teeth, and pretend to close my eyes while I really keep one slit open to take notes.)
My brain isn’t the only thing around here generating magnetic fields. The McGovern is surrounded by far stronger signals — the earth, the computers next door, the traffic outside and the Red Line underfoot — and all of them are capable of trashing the MEG’s exquisitely sensitive sensors. Comparatively, what my brain is producing is pretty puny – a trillionth to a billionth as strong as the earth’s field, according to Charles Jennings, the director of the McGovern Institute Neurotechnology Program.
That’s why the MEG is only half the deal. The actual room where I’m sitting is what makes this particular system so technologically advanced — the chamber is a sealed, standalone cube, all six sides made from a triple layer of µ-metal (that’s mu-metal), which re-routes outside magnetic fields around and away from the MEG itself — not unlike a hollow rock in a river eddy. The door alone weighs 400 pounds; the entire chamber, which took a team of specialists two straight weeks to assemble, clocks in at 11 tons. But it allows the scanner to read a cleaner signal in more chaotic locations than has ever before been possible.
THE BIG PICTURE
This technology was invented here at MIT 40 years ago (original model pictured above), and has been quietly making inroads into the research community ever since. But because of its sensitivity to outside interference, it still has yet to achieve anywhere near the popularity of the fMRI. That’s what makes this latest model so exciting — it’s finally given the MEG the ability to function where it’s needed most: busy hospitals and urban research centers. It is the tech’s best chance, Jennings tells me, to at last go mainstream.
Me? I’m sold. Never has a scan been easier to sit through. Two minutes in the chair and five at the computer were all I needed for a quick-and-dirty snapshot of my innermost thoughts:
Source URL: https://www.bostonmagazine.com/news/2011/04/12/geek-beat-mits-shiny-new-mind-reader/
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