Forget electrodes - these microcoils may be the future of brain implants

 Image credit:  Fibromyalgia News Today

I've written A LOT about brain implants. They still never cease to amaze me. You take an electrode, stick into the ball of goop that is the brain, connect it to wires running out of the skull, and voila - if all goes well, the brain's now got a straight line of communication to a computer, or even the internet.

But they're not perfect. Electrodes tend to rather promiscuous - when they zap neurons into action, it's really hard to limit that activity to a specific neural circuit. The result is noise, noise, noise, to the point the brain can't figure out what the hell its hyperactive neurons are trying to do.

So far scientists seem to have somewhat worked around the problem with brain-machine interfaces that let paralyzed patients type with their eyes, for example. But for other problems, the electrode is seriously hampering technological advance.

Take restoring vision. Vision, like everything else the brain processes, is just patterns of activity. So if we can artificially zap the visual cortex with a pattern that induces horizontal lines of black-and-white light, for example, you can in theory trick the brain into "seeing" that pattern without eyes! Pretty neat. 

The problem is that electrodes activate so many neurons that the above is impossible to do cleanly. This is where magnets come in.

A team at Harvard and the Palo Alto Research Centre (PARC) came up with a teeny tiny magnet that you can safely jam into the brain. Pulse the magnet with electricity, and it generates an magnetic field that, in turn, can activate neurons. 

Magnets are awesome in many ways, but as a brain implant, two perks stand out:

  1. the electrical field they generate is directional, meaning that you can sort of select the neurons you want to activate by tweaking the field;
  2. magnetic waves can pass through scar tissue, so they're good for long-term implants.

So far, the tiny coils have been tested in rodents in a game of flicking whiskers. In a few months, scientists will be starting tests on primates with slightly adapted versions of the coils. Eventually the goal is to teach monkeys to navigate mazes, without ever using their eyes. 

Personally, I'd love to see a science paper starring a blind-folded monkey or two.

Get the details over at - as usual - Singularity Hub