A recent letter to Nature describes a series of experiments involving rhesus macaque monkeys and Brain-Machine-Brain-Interfaces (BMBIs), in which these animals were able to move an object with their thoughts, and could recognize the texture of the objects they touched through an interface. The monkeys used a virtual reality arm to “touch” objects that were visually identical, but had unique textures, and the monkeys were able to identify the differing textures. Essentially, while previous experiments demonstrated a one way connection (brain to machine), these experiments demonstrated that tactile feedback could occur with brain-only connections.
This research was conducted by a group at Duke University Medical Center, led by Miguel Nicolelis, a professor of neurobiology. All experimentation was approved by Duke’s IACUC. Two monkeys were each implanted with 4 array electrodes, in areas of the M1 and S1 brain regions, which control movement and sensation. The monkeys were trained to use a computer cursor or a virtual reality arm to reach objects, and were rewarded when they selected an object that had a unique texture. Intracortical microstimulation (ICMS) was used to provide feedback, after the virtual object was touched, within 10 msec of the event. Statistical analyses showed that “guessing” which object was unique was not occurring; the monkeys could perceive the targets.
The ultimate goal of these types of experiments is to lead to brain-only control of movements for humans where physical limitations impair movement. These impairments may come from disease or physical trauma, including limb amputations. In addition, brain communication with external sources not limited to movement could be explored, as could restoring neural connections between brain processes that for various reasons are no longer connected. Nicolelis’s main goal is to create a “wearable robot” according to an article describing the research in Scientific American.