Whilst this short piece is technically about the BrainGate controller,
it never mentions it by name. However, the hardware shown, is indeed
that. A 4mm x 4mm chip with an array of 10 x 10 electrodes on it. It
is implanted into the motor cortex of the monkey, in the same manner
as has been done to monkeys and humans for the past half decade.
What has changed however, is the fidelity of which we can record brain
signals, and the degree of understanding we now have as to what all
those neural codes actually mean. Some parts of the presentation rehash
old ground - such as the monkey coming to accept the arm as part of
their natural body, and treating it as just another body part. What
is new is the fine motor control shown, in being able to operate a wrist
without really thinking about it.
A word of caution is advised on taking the podcast at face value. What
is not mentioned here is that the arm is constrained in its range of
movement. If the brain signals for it to jerk out quickly, say, the
software in the arm will damp down the more violent movements, and ignore
those that go beyond a set range. This is not directly meant to stop
the monkey from using the arm to batter down its cage or break its restraints,
but serves as a safety mechanism for both researchers and the monkey,
from violent impulses or too much force.
However, it does mean that not all the motion shown is entirely the
monkey's brain. If it were not for these smoothing and slowing algorithms,
the movement would still be significantly more erratic than shown