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Stanford’s Mike Greicius, MD, appears to have nudged brain imaging in the direction of being able to decipher what real people in the real world are doing with their brains:
In a just-published study described here, Greicius and his team used a workhorse brain-imaging technology called functional magnetic-resonance imaging, or fMRI, in a novel way that let them determine whether experimental subjects were counting backwards by threes, singing silently to themselves, recalling events of the day, or just vegging out.
By examining the resulting brain scans, it was possible to identify which of the four brain states was involved, with 85 percent accuracy. (With blind luck, that would have been only 25 percent.) Even when those scans lasted only one minute – and in the real world, who’s going to spend more than that long counting backwards by threes? – the images could be assigned to the correct mental state 80 percent of the time.
Standard versions of fMRI approaches require those being scanned to start and stop their mental task on a dime. But the new method lets subjects move their mental machinery at a more freewheeling, leisurely pace reflecting real-life thought processes. This, and some more-technical aspects of the new approach, make it ideal for studying various brain disorders. (Alzheimer’s patients, for example, have trouble following directions like: “Okay, ready, get set, SUBTRACT!! Okay, STOP SUBTRACTING!!”)
Imagine a device based on this methodology finding its way into use in, let’s say, airports. Might it casually distinguish a mental state best befitting a suicide bomber from the more desultory malevolence 85 percent of us harbor as we count backwards from the 5,000 people in front of us in the security line, mutter our favorite curses under our breath, try to recall whether we packed the deodorant, or just veg out?
Well, maybe not. MRI generates magnetic fields on the order of 2 or 3 Teslas. So the detector’s developers would first have to figure out how to keep it from ripping the rivets right out of your jeans, exposing more than your state of mind.
Photo by Digital Shotgun