Watch a video showing what happens in our brains when we think

This article first appeared in The Checkup, MIT Technology Review’s weekly biotech newsletter. To receive it in your inbox every Thursday, and read articles like this first, sign up here. What does a thought look like? We can think about thoughts resulting from shared signals between some of the billions of neurons in our brains. Various chemicals are…
Watch a video showing what happens in our brains when we think

This is what the activity looked like:

“This is basically the brain thinking,” says Rapoport. “You’re seeing the physical manifestation of thought.”

In this video, which I’ve converted to a GIF, you can see the pattern of electrical activity in the man’s brain as he recites numbers. Each dot represents the voltage sensed by an electrode on the array on the man’s brain, over a region involved in speech. The reds and oranges represent higher voltages, while the blues and purples represent lower ones. The video has been slowed down 20-fold, because “thoughts happen faster than the eye can see,” says Rapoport.

This approach allows neuroscientists to visualize what happens in the brain when we speak—and when we plan to speak. “We can decode his intention to say a word even before he says it,” says Rapoport. That’s important—scientists hope technologies will interpret these kinds of planning signals to help some individuals communicate.

For the time being, Rapoport and his colleagues are only testing their electrodes in volunteers who are already scheduled to have brain surgery. The electrodes are implanted, tested, and removed during a planned operation. The company announced in May that the team had broken a record for the greatest number of electrodes placed on a human brain at any one time—a whopping 4,096.

Rapoport hopes the US Food and Drug Administration will approve his device in the coming months. “That will unlock … what we hope will be a new standard of care,” he says.


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