Equipped with advanced brain-computer interfaces (BCIs), monkeys demonstrated their ability to navigate various virtual worlds using only their thoughts. Researchers aim to use these findings to help individuals with paralysis explore virtual environments and control motorized wheelchairs intuitively.

Peter Jansen and colleagues at the University of Leuven in Belgium conducted transplants in three rhesus macaques (Macaca mulatta) fitted with BCIs. Each monkey received three implants containing 96 electrodes strategically placed in the primary motor cortex, dorsal, and ventral premotor cortex. The primary motor cortex is crucial in BCI research and is associated with physical movement, while the other two regions facilitate abstract movement planning. Electrical signals from the implants were interpreted by an AI model to control a virtual reality (VR) avatar as the monkey interacted with a 3D monitor.

During the experiment, the monkeys could control a sphere that moved across a VR landscape from a fixed viewpoint. They progressed to directing an animated monkey avatar from a third-person perspective, similar to popular video games. Subsequent trials allowed the monkeys to navigate their virtual surroundings by interacting with doors and moving from room to room.

Unlike previous BCI experiments involving humans, which required physical movements like finger motions to manipulate cursors, Janssen believes that placing sensors within the monkeys facilitated a more intuitive connection to movement.

“We can’t directly communicate with these monkeys, but fundamentally, we think this method provides a more natural way to control systems,” Janssen remarked. He likened current BCI experiences to “trying to move your ears,” noting that this disconnection can be frustrating and requires extended practice to master.

Janssen is optimistic that this innovative approach may eventually translate to humans, empowering those with paralysis to navigate virtual environments or control electric wheelchairs with ease. However, he also acknowledged the complexities of precise sensor placements in human subjects, stating, “It requires thorough research to pinpoint the right areas, given our limited understanding of these regions in humans. Nevertheless, once identified, it should be feasible and even simpler since humans can articulate their experiences.”

Andrew Jackson from the University of Newcastle in the UK commended the study’s ability to allow monkeys to maintain control across various perspectives and situations. This suggests that BCI may engage abstract parts of the brain related to movement, providing an adaptable approach similar to how people switch between different video games using the same controller.

“With a multitude of buttons available, different games demand specific mappings that can be challenging to navigate,” Jackson noted. “However, this approach simplifies the process as there are only limited combinations to explore. A scenario requiring you to abandon your controller for an external task would present a greater challenge.”

Preliminary trials of simpler BCIs have been conducted on humans. For instance, a paralyzed individual successfully piloted a virtual drone through an intricate obstacle course merely by envisioning finger movements, with AI interpreting the resulting signals. In another instance, imagining writing with a pen enabled a computer to transcribe thoughts into text.

In 2024, Neuralink, co-founded by the controversial billionaire Elon Musk, announced a groundbreaking development: the first human BCI installation, allowing cursor control on a computer. However, reports later revealed that approximately 85% of the electrode threads had misaligned within a month, compromising functionality. Neuralink has faced scrutiny over suspicions of animal mistreatment, claims Musk has denied while also navigating a U.S. government investigation tied to the experiment. The situation has seemingly stalled under President Donald Trump.