Seung-Schik Yoo of Harvard Medical School in Boston and colleagues created a non-invasive brain-to-brain interface that allowed human participants to move a rat's tail with their thoughts via EEG and focused ultrasound signals. Simply by thinking the appropriate thought, the BBI allows the human to control the rat’s tail. This is one of the most important steps towards BBIs that allow for telepathic links between two or more humans — which is a good thing in the case of friends and family, but terrifying if you stop to think about the nefarious possibilities of a fascist dictatorship with mind control tech.
In recent years there have been huge advances in the field of brain-computer interfaces, where your thoughts are detected and “understood” by a sensor attached to a computer, but relatively little work has been done in the opposite direction (computer-brain interfaces). This is because it’s one thing for a computer to work out what a human is thinking (by asking or observing their actions), but another thing entirely to inject new thoughts into a human brain. To put it bluntly, we have almost no idea of how thoughts are encoded by neurons in the brain. For now, the best we can do is create a computer-brain interface that stimulates a region of the brain that’s known to create a certain reaction — such as the specific part of the motor cortex that’s in charge of your fingers. We don’t have the power to move your fingers in a specific way — that would require knowing the brain’s encoding scheme — but we can make them jerk around.
Which brings us neatly onto Harvard’s human-mouse brain-to-brain interface. The human wears a run-of-the-mill EEG-based BCI, while the mouse is equipped with a focused ultrasound (FUS) computer-brain interface (CBI). FUS is a relatively new technology that allows the researchers to excite a very specific region of neurons in the rat’s brain using an ultrasound signal. The main advantage of FUS is that, unlike most brain-stimulation techniques, such as DBS, it isn’t invasive. For now it looks like the FUS equipment is fairly bulky, but future versions might be small enough for use in everyday human CBIs.
With the EEG equipped, the BCI detects whenever the human looks at a specific pattern on a computer screen. The BCI then fires off a command to rat’s CBI, which causes ultrasound to be beamed into the region of the rat’s motor cortex that deals with tail movement. As you can see in the video above, this causes the rat’s tail to move. The researchers report that the human BCI has an accuracy of 94%, and that it generally takes around 1.5 seconds for the entire process — from the human deciding to look at the screen, through to the movement of the rat’s tail. In theory, the human could trigger a rodent tail-wag by simply thinking about it, rather than having to look at a specific pattern — but presumably, for the sake of this experiment, the researchers wanted to focus on the FUS CBI, rather than the BCI.
Moving forward, the researchers now need to work on the transmitting of more complex ideas, such as hunger or sexual arousal, from human to rat. At some point, they’ll also have to put the FUS CBI on a human, to see if thoughts can be transferred in the opposite direction. Finally, we’ll need to combine an EEG and FUS into a single unit, to allow for bidirectional sharing of thoughts and ideas. Human-to-human telepathy is the most obvious use, but what if the same bidirectional technology also allows us to really communicate with animals, such as dogs? There would be huge ethical concerns, of course, especially if a dictatorial tyrant uses the tech to control our thoughts — but the same can be said of almost every futuristic, transhumanist technology.