Update: a 2021 publication demonstrates promising early results in humans.
We can learn a lot about how the brain works by poking it and seeing what happens. Brain stimulation techniques have been around for a while, using magnetic fields or electric current to make neurons fire. However, these noninvasive procedures have been limited to the outer parts of the brain. It hasn’t been possible to investigate neural structures that are well past the surface, without physically sticking an electrode in there—and drilling through the skull of a living person or animal is, for many reasons, not ideal.
A new technique promises to offer deep brain stimulation without surgery. It’s called temporal interference, or TI, and involves shooting two different electric fields at the brain via electrodes on the scalp. Neither field on its own is enough to stimulate the brain, but where the two meet, the interference pattern creates a region of stimulation. Here, crossing the streams is a good thing.
Results of early TI tests have just been published in the journal Cell, and Discover’s Neuroskeptic has a nice summary of the technique and its possible limitations. It’s only been tested in mice so far, but human tests may be coming soon.
If TI works in humans, there could be exciting applications, not only for learning more about how the brain works, but for treating neurological deficits, and maybe (big maybe) even tweaking cognitive performance in healthy people.
We’ll keep an eye on this technology as it evolves, but there is reason to be cautiously excited for TI’s potential to revolutionize knowledge of the brain and brain health.