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Brain sends signals to computer

rand at mindless.com rand at mindless.com
Thu Oct 22 07:44:22 EST 1998

>Has anyone read the AP article by Lori Wiechman dated Oct. 21 that
>describes research by an Emory Prof, MD about implanting a device into a
>stroke victims brain that lets him choose phrases from a computer such as
>"hello" and "I'm thirsty"?  What is the neruoscience behind this?  Why the
>glass cone?

Interesting article. Here's the part you'd be most interested in:

The implants consist of two hollow glass cones, no
bigger than the tip of a ballpoint pen, placed into the
brain's motor cortex, which controls body
movements. The glass cones are laced with
neurotrophic chemicals extracted from the
patients' own knees. These chemicals encourage nerve
growth so, over several months, neurons in the cortex
grow pathways into the cones and attach themselves to
tiny electrodes mounted inside.

To decide where to place the implants, Bakay and
his colleagues used a magnetic resonance imaging
scanner to reveal the most active regions of each
patient's motor cortex. Once nerves had grown into the
cones, the patients were asked to think about moving
various parts of their body. The responses of the
electrodes in the cones were monitored and translated into
commands for the computer cursor. At the moment
these commands are quite simple: up and down for
one cone, and left and right for the other. But
this is just the start, says Bakay.

Depending on exactly which nerves grow into the
cones, each patient may have to think about
moving a different part of his or her body to achieve the
desired cursor movement. They are trained to use the
device by listening to a buzzer which becomes faster
and louder when they are thinking along the right
lines. Controlling the cursor soon becomes second
nature, says Bakay.

The implants are powered by a coil worn outside
the skull in a cap. This induces a small current in
a transmitter-receiver placed just inside the
skull. It transmits to an amplifier in the cap, which
boosts the signal and sends it to the computer.

Steven Edwards - rand at mindless.com
Spinal Confusion - http://come.to/SpinalConfusion

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