Monkey Brain

In research having a wide range of applications, neuroscientist Daniella Meeker, a graduate student at the California Institute of Technology in Pasadena, has taught a rhesus monkey to move a computer cursor by thought alone. Meeker dubs this ability "Cognitive Prosthetic Control."

The most obvious application of this research is in enabling paralyzed patients to move — perhaps by using robotic limbs — and to control their surroundings via an interface with home automation technology. This same approach could be modified to empower paralyzed patients to communicate using text-to-speech technology. It could also be used to empower communication with the world at large via the Internet.

Meeker and her team, students in Professor Richard Andersen's Lab, focused on an area of the brain known as the posterior parietal cortex (PPC) (see University Laboratory of Physiology, Oxford , for more information on this area of the brain).

Using high-tech brain scans, the researchers pinpointed the small clumps of cells in this region that seemed to initiate the desire to carry out specific body movements.

Then the team implanted electrodes in the PPC of a rhesus monkey trained to play a simple video game. Using Magnetic Resonance Imaging (MRI), the team "mapped" the different patterns of electrical activity in the region that corresponded to specific hand movements that positioned the computer cursor.

The next step was to train the monkey to think about a movement without doing it. A computer program connected to the implanted electrodes interpreted the monkey's thoughts by tracking high frequency spikes of brain cell activity. The computer program then moved the cursor based on the "mapping," in accordance with the monkey's desires — left or right, up or down, wherever "the electrical (brain) pattern tells us the monkey is planning to reach," according to Meeker. "In fact," she said, "we found that he became quite reluctant to move his arm to the reach command once the cursor was introduced into the game. Apparently it was easier just to think about reaching" (Reuters Health, as quoted in Brainland).

Meeker said her group's work differs from previous research in that it seeks to replicate the brain-motor connection "at the level of the first inclination to make a movement." She noted: "This supposes that much of the downstream function — which would be normally implemented by the rest of the brain, the spinal cord and muscles — can be relegated to intelligent machines" (Reuters Health, as quoted in Brainland).

This research may be the start of fulfilling a long-term dream of many neuroscientists: a technology with which paraplegics, quadriplegics, and other paralysis patients (such as those with amyotrophic lateral sclerosis) may achieve full mental control of robotic limbs or communication devices.

The technology is still primitive; it will take years to perfect the programs to the level required for human applications, and there are serious risks inherent in neurosurgery. The risk may be worth it to a patient "locked-in" to his body, but it may not be justifiable for "Terminator"-type applications that would allow the minds of healthy individuals to meld with machines.

There are other research groups working on brain-activity tracking methods that do not rely on surgically implanted electrodes; these technologies may substantially reduce the risks in cognitive prosthetic control technologies.

Some day, telekinesis may become as commonplace as the ability to drive an automobile.

For more information about the neural prosthetics field, see Stanford.