Controlling a rat with your mind

A wireless brain-to-brain interface allows humans to guide live rats through a complex maze…

Controlling another living creature through the power of your brain is no longer limited to science fiction. We’re not talking about superpowers, but rather a brain-to-brain interface, in which a computer allows transfer of commands from one brain to another.

The set-up by Shaomin Zhang and his team from Zhejiang University, China, allowed a human manipulator to use their brain power to guide a rat through a 3D maze. Human brain activity is recorded using electrodes placed on the surface of the head. The manipulator thinks about moving their own arm left or right to instruct the rat to turn, and about blinking to instruct the rat to move forward. This information is wirelessly sent to a computer which decodes the signal and outputs a command to electrodes which deliver an electrical stimulus in the rat’s brain. The manipulator gets real-time visual feedback by watching a video of the rat moving through the maze.

The humans and rats first familiarized themselves with the set up in an eight-arm maze – eight segments branching off from a central point. The rats were then introduced to a more complex maze, complete with steps, a tunnel, and pillars to be avoided. Rats were guided through this maze – and back on track when they steered away from the correct route – in less than 5 minutes.

This is the first experiment of this type featuring a live mammal in a complex environment. An important advance is the use of motor instead of visual decisions (eg staring at light) to initiate a command. This avoids the need for manipulators to switch their attention back and forth from the visual command screen and the video of the rat moving. Furthermore, comparing two control algorithms with different thresholds for distinguishing between instructions and background noise showed reduced efficiency for the slower algorithm. Timing and rapid instructions are crucial to control an animal with its own motivation to move.

Brain-to-brain connection between two live mammals of two different species has huge implications. Brain-machine interfaces have gathered a lot of interest for therapeutic applications, with the goal of restoring motor ability, sensory perception or speech. The potential of connecting two humans via their brains – and across long distances using wireless internet – is fascinating, but raises serious ethical questions. When should this technology be used? In which direction will command flow? Can autonomously generated decisions can override stimulations from the interface? As further improvements in the software increase reliability of transmission, these considerations will need to be addressed, or we may find ourselves thick in the plot of the best/worst sci-fi movie…