Brain chip sparks nerve pathways

Researchers at the University of Washington are working on an implantable electronic chip that may help establish new nerve connections in the part of the brain that controls movement.

Their study published in Nature showed such a device can induce brain changes in monkeys lasting more than a week. Strengthening of weak connections through this mechanism may have potential in the rehabilitation of patients with brain injuries, stroke, or paralysis.

Using the brain’s motor impulses to control computers or mechanical devices has been the main driver for brain-computer interfaces (BCI). The recent study suggests that the brain's nerve signals can be harnessed to create changes within itself.

The researchers tested a called a Neurochip miniature, self-contained device with a tiny computer chip. The devices were placed on top of the heads of monkeys who were free to carry out their usual behaviors, including sleep.

The Neurochip records the activity of motor cortex cells and can convert this activity into a stimulus that can be sent back to the brain, spinal cord, or muscle, and set up an artificial connection that operates continuously during normal behavior. This recurrent brain-computer interface creates an artificial motor pathway that the brain may learn to use to compensate for impaired pathways.

Timing is critical for creating these connections, the researchers said. The conditioning effect occurs only if the delay between the recorded activity and the stimulation is brief enough. The changes are produced in a day of continuous conditioning with the recurrent brain-computer interface, but last for many days after the circuit is turned off.