Three rhesus macaque monkeys equipped with brain-computer interfaces navigated virtual environments using only their thoughts. Researchers implanted around 300 electrodes in motor and premotor cortex areas to enable this control. The experiments aim to improve intuitive control for people with paralysis.
Peter Janssen and colleagues at KU Leuven in Belgium implanted three rhesus macaque monkeys with brain-computer interfaces. Each monkey received three arrays of 96 electrodes, totaling about 300, placed in the primary motor cortex, dorsal premotor cortex, and ventral premotor cortex. These areas relate to movement execution and higher-level planning. An AI model decoded the neural signals to steer virtual reality avatars on a 3D monitor the monkeys viewed. The animals controlled a sphere across virtual landscapes from a fixed viewpoint, animated monkey avatars from a third-person perspective like in video games, and even navigated virtual buildings by opening doors and moving between rooms. Janssen described the method as more intuitive than prior BCIs, which often require imagining specific physical actions like finger movements. “We cannot ask these monkeys, of course, but we just think that it’s a more intuitive way of controlling a computer, basically,” Janssen said. He noted that users of existing systems sometimes liken them to “trying to move your ears,” a skill that can take weeks to master. Janssen believes the approach could help humans with paralysis navigate virtual worlds or wheelchairs more naturally, though human implant locations need further study. “There’s a bit of work necessary to know exactly where to implant a human... But once we figure that out, it should be possible. It should actually be easier because you can explain to the human what they are supposed to do,” he added. Andrew Jackson at Newcastle University praised the monkeys' ability to adapt control across viewpoints and contexts, suggesting the implants tap into abstract movement representations in the brain. The findings appear in Science Advances.
