A Chinese research team has developed the ability to mind control a rodent, building a wireless brain-to-brain system that enables a human to move the “rat cyborg” through a maze.
The research, published in Nature’s Scientific Reports on Feb. 4, details a brain-to-brain interface (BBI) that connects a human brain to a computer, which then decodes and stimulates the rat brain to move. The researchers detail their methodology in a delightful section of the published paper called “rat cyborg preparation”, explaining how they implanted electrodes in two sections of the rat brain.
The researchers then “trained” the rats by using the electrodes to produce certain movements, which they wirelessly sent to the rat’s brain via a tiny rat-backpack containing the stimulator.
Their first test for the rat cyborg involved a maze shaped like an eight-armed asterisk. The rat started in one arm of the maze and was tasked with moving into another arm. The human controller was fitted with a device known as an electroencephalogram (EEG) to measure brain signals. The EEG was connected directly to a computer. The computer would then decode the human brain signal and pass it through a model to stimulate the rat’s brain and tell it to move in a particular direction.
Using the EEG to measure the human brain signal means the researchers don’t have to directly connect electrodes to a human brain — that’s a good thing, but it makes the signal weaker.
“EEG measures electrical activity in the brain, through the skull. EEG gives us a fast signal, but because the skull and skin are not very conductive, and are quite thick, it doesn’t give a good spatial signal from the brain,” says Angus McMorland, a biomedical engineer at the University of Auckland and not associated with the study. McMorland compares the signals from the EEG to reading a book “through several layers of frosted glass.”