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Monkey forced to control sedated “avatar” in cruel experiment

Scientists in the USA have managed to force a “master” monkey to control the movements of a sedated “avatar” monkey using only its mind. It may sound like something out of a Hollywood movie, but the reality is far from glamorous.

In order to carry out the experiment, electrodes had to be surgically implanted into the brains and spinal cords of two adult male rhesus monkeys so that they could be ‘connected’ to each other with cables. The “avatar” monkey, who also had electrodes implanted into his arm muscles, was then sedated with his paw placed over a joystick that controlled a computer cursor. In a separate enclosure, the “master” monkey was restrained in a specially designed chair that forced him to remain completely still with his head fixed to a post. He was then positioned directly in front of a computer screen and forced to use his mind to stimulate the “avatar” monkey’s muscles to move the cursor in order to receive a juice reward. Cruelly, monkeys are typically deprived of water in studies such as this to motivate them.

The researchers claim that the study was carried out in order to help paralysed people move again, however, they themselves admit that the ‘avatar’ monkey was not paralysed in the same way as humans would be. In addition, several studies have already been carried out using human volunteers that offer a much more relevant progress for the rehabilitation of movement in patients with paralysis. For example, in another US study, electrodes connected to a prosthetic arm were implanted into the brain of a tetraplegic 52-year-old woman3. After 13 weeks of training, the woman was able to successfully use her mind to control the arm and even carry out complex movements such as reaching and grasping. We are appalled to hear of this monkey experiment and urge people to consider the real suffering and hype behind these apparently glamorous science-tech advancements.




2.       A cortical-spinal prosthesis for targeted limb movement in paralysed primate avatars. (2014). Nature Communications, 5:3237. DOI: 10.1038/ncomms4237. Original article can be found here:

3.       High-performance neuroprosthetic control by an individual with tetraplegia. (2013).The Lancet, 381(9866): 557-564.