Scientists have successfully used computer chips to link two monkeys together, allowing one monkey's brain to control the other's body movement.

Researchers say they hope their work - partly inspired by Hollywood blockbuster Avatar - will lead to the development of implants for patients who have nerve or spinal cord paralysis.

Harvard neurosurgeon Ziv Williams, who co-authored the study published in the journal Nature Communications, says the paper aimed to find possible ways to treat people with cervical spinal cord injuries and are quadriplegic or have had brain stem strokes.

"What we basically did was create a functional cortical to spinal bypass where we're able to record neural signals in the brain, extract information about what the monkey is intending on doing and then basically stimulating the spinal cord to produce movements in their paralysed limb to those same intended target locations," Dr Williams said.

"For example, if the monkey is intending on moving upwards, we would select specific electrode contacts in the spinal cord to stimulate a movement that reaches that exact same target location.

The research was partly inspired by the film Avatar in which a character's thoughts were used to control another. ( www.imdb.com )

"In some cases actually the first monkey just needed to think about what they wanted to do and then the other monkey would make the movement."

Dr Williams said the "master monkey" was implanted with a microchip in the area of their brain responsible for thinking about movement and the neurons were recorded, based on the patterns of activity.

"We could figure out what the monkey was intending on moving or intending on doing - for example you know, moving up, down, left, right - and then at the same time we implanted a microchip in the spinal cord of the avatar and then we stimulated those areas based on what the other monkey was thinking," he said.

"So the hook-up was basically a computational link where we basically matched everything that the monkey, that the master, was thinking about and then matched that with movements produced in the avatar.

"It was actually through a computer interface but in theory you could do it wirelessly as well."

Research could lead to speech, robotic arm treatment

Dr Williams says it is hoped the research will help provide spinal injury patients with more treatment options.

"I'm also a neurosurgeon, so I treat patients with paralysis and I do surgery for patients that have spinal cord injury, [and] often times it's very challenging, even if you're able to technically treat the cause of the injury," he said.

"Once the injury happens there is very little that we are able to do currently to treat patients with severe paralysis.

"So ultimately this experiment was really meant as a proof of concept - that you're able to create this cortical to spinal bypass or functional bypass and with the ultimate goal of being able to maybe translate this into the clinical setting but there is still several hurdles.

"Probably the biggest one is to really show that this can produce more naturalistic movements, movements to many different targets, something that can be useful for example pointing to something, grasping an object and bringing it.

"Those are things that we haven't gotten to the point where we've been able to do yet."

The study only looked at movement in the animals, however, Dr Williams says if further trials are successful the technique may be extrapolated into either movement within a paralysed arm, speech or even a robotic limb.

"People have actually recently looked at trying to record neural activity in people and with a goal of using neural activity in speech areas to resynthesis either mechanical speech," Dr Williams said.

"I'd say probably, more practically speaking, it would be mechanical speech through their own voice box but that will still take a lot of different pieces to come together for that to be practically usable."