Researchers at Harvard University have created the first noninvasive brain-to-brain interface (BBI) between a human… and a rat. 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.