Brain implants that allow the direct interface between the human brain and machines have been in development for some time now. However, aside from the daunting task of figuring out how to couple solid-state electronics with what amounts to a biological computer, another problem faced by researchers is the body’s reaction to foreign objects: implanted electrodes work just fine when initially inserted, but over time scar tissue builds up over them, hampering their ability to both read and transmit electrical signals between themselves and their targeted neurons. However, researchers at Harvard Medical School have come up with a new method of implantation that may be able to avoid this problem, allowing for long-term use of such implants.
Typically, brain implants penetrate directly into the brain itself, using minute electrical signals to interact directly with the areas of the organ that need to be either read or stimulated. The insertion itself unavoidably causes an injury to the site, prompting the eventual buildup of the problematic scar tissue in question. This new implant uses magnetic fields to stimulate targeted neurons instead of direct electrical impulses: while scar tissue insulates against electrical flow, magnetic fields will pass through it unimpeded.
This new implant is a hair-like device that incorporates an array of microscopic coils that sends a strong, tightly targeted magnetic field into the area of the brain it is intended to interact with. While it is intended to betested by placing it on the surface of the brain, it theoretically should still retain its long-term effectivness if it is also inserted into the organ.
The implant will be tested on monkeys, starting next month, to transmit data into their visual cortexes — the initial intent for this implant is to improve the long-term viability of existing technology that allows blind people to see.
“At the end of that we hope to have monkeys be able to navigate a maze, just by perceiving light and dark or basic geometric patterns,” explains Bernard Casse, a researcher at the PARC research institute, where the new implant design was invented.
If the new design is successful, it could be used to build implants that could be used to stimulate neurons in other parts of the body: aside from being able to stimulate various areas of the brain, Casse says he’s interested in using the technology on the vagus nerve to control the symptoms of PTSD sufferers.