Monkey controls limb movements of 'avatar' using its mind

In the movie Avatar, humans operate the bodies of a human-hybrid species, called Na'vi, with their minds. Now, researchers from Harvard Medical School in Boston, MA, have carried out a similar technique in monkeys - using neural devices that allowed an alert monkey to control the mind of one that was temporarily paralyzed.

The research team, including Ziv Williams of the Department of Neurosurgery at Harvard Medical School, says the findings provide proof of concept that such strategies could be used in the rehabilitation of patients who are paralyzed.

The research was recently published in the journal Nature Communications.

According to the investigators, previous research has demonstrated that neurons in many parts of the brain are able to control external devices, such as a cursor on a computer screen. This direct communication is known as brain-machine interface ( BMI ).

The researchers say recent studies have even shown that using BMIs could potentially control robotic limbs.

In 2012, Medical News Today reported on a study detailing how a paralyzed woman was able to control a robotic prosthetic hand with her thoughts.

But the research team notes that although findings such as these are an important step forward in motor control, another important goal has been to determine how a paralyzed individual may be able to control the movement of their own limbs.

However, the study authors say there have been problems reaching this goal.

"Unlike the control of external devices, a distinct problem in attaining limb movement control is that the output of the motor system - for example, the corticospinal tract and its associated afferents - is generally not explicitly known," they explain.

"The exact combination of successive agonistic and antagonistic muscle contractions naturally used to produce limb movement to different targets in space is difficult to explicitly ascertain or reproduce."

But the researchers say they aimed to address these problems by focusing on the specific movement targets themselves, rather than intervening in movement trajectory.

Avatar monkey controlled through pre-recorded neural activity

For the study, the research team used two Rhesus macaque monkeys aged between 6 and 8 years old.

One monkey was sedated and used as the "avatar," while the other was used as the "master" monkey. Both monkeys took turns being either the avatar or the master throughout various sessions.