For many years Dr. Eberhard Fetz, professor of physiology and biophysics, and his team from the University of Washington have studied how the brains of monkeys control their limb muscles. When awake, the brain continuously governs the body's voluntary movements. This is largely done through the activity of nerve cells in the part of the brain called the motor cortex. These nerve cells, or neurons, send signals down to the spinal cord to control the contraction of certain muscles, like those in the arms and legs.
The possibility that these neural signals can be recorded directly and used to operate a computer or to control mechanical devices outside of the body has been driving the rapidly expanding field of brain-computer interfaces. The recent study suggests that the brain's nerve signals can be harnessed to create changes within itself.
The researchers tested a 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 behaviours, including sleep. Called a Neurochip, the brain-computer interface was developed by Mavoori for his doctoral thesis.
"The Neurochip records the activity of motor cortex cells," Fetz explained, "It can convert this activity into a stimulus that can be sent back to the brain, spinal cord, or muscle, and thereby set up an artificial connection that operates continuously during normal behaviour. 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 conditioning effect occurs only if the delay between the recorded activity and the stimulation is brief enough. In the future this mechanism may have potential in stroke and brain injury rehabilitation.
COMPAMED.de; Source: University of Washington