Direct mind-to-mind communication in humans

Edited August 31st, 2014 to add in a few of my thoughts about the paper.

Here’s something right out of science fiction: a team of neuroscientists in Spain developed a system that allows a person to transmit the words “hola” and “ciao” from India directly to the minds of three people in France.

This work builds on previous studies using brain-computer and computer-brain interfaces to translate electrical activity of the cortex into digital bits, and vice-versa.

Each word was encoded as a string of “0s” and “1s”, and repeated seven times for redundancy. The researchers presented these bits one-by-one to the volunteer who played the role of the emitter. The volunteer was then asked to do a simple task on a computer: he had to imagine moving an animated ball to a target at the right of the screen with either his hands (for 1s) or feet (for 0s). The bit was successfully encoded if he managed to hit the target with the ball (see graph below). At the same time, the electrical activity of his cortex – the outermost layer of the brain – was recorded with EEG.  A brain-computer interface then encoded the brain waves into digital bits and sent them to Paris using email. (Yeah, who would’ve guessed? Email!)

Figure 1 of the paper.

Figure 1 of the paper.

The three receiver volunteers were all hooked up to a Transcranial Magnetic Stimulation machine, which (you guessed it!) stimulates brain activity with a magnetic coil. When the coil is placed above a certain part of the visual cortex, the volunteer would see flashes of bright light, called phosphenes; rotate the coil 90 degrees, and the phosphenes disappear. Thus whether or not phosphenes are present acts as a binary code: the absence of these light flashes means 0, and their presence is decoded as 1. To minimize external stimuli, researchers asked the volunteers to wear eye masks and earplugs, and made sure that the coil would always move away from the volunteer’s heads before rotating.

Figure 2 of the paper. That's one cool-looking EEG cap on the left!

Figure 2 of the paper. That's one cool-looking EEG cap on the left!

Once the computer-brain interface receives the email containing the transmitter’s neural code, it reads through the bits one-by-one. For 1s, the system automatically moves the TMS magnetic coil to the correct orientation so that the receivers saw phosphenes, and their responses were recorded. 0s were transmitted to the receivers’ brains and documented in the same way.

Researchers gave the system two tries, and the words were successfully transmitted each time. It was a painfully slow process – the average speed was 2 bits per minute. However, the error rate was remarkably low at only 4% of all bits for the second session.

Although it's true that, as one reader put it, "this just seems like a badly designed system for communicating in Morse code", this is nonetheless the first time that direct brain-to-brain communication has been demonstrated in humans using fully noninvasive technology. The progress is incremental: after all, both emitting and receiving systems have been tested before, and I have to admit the paper seemed a bit gimmicky to me when I first read it. But if you take a step back and look at the big picture, holy crap!, someone communicated two words over thousands of miles simply by thinking! That's pretty darn cool to me.

While quite a stretch, the researchers envision that a person’s own thoughts may be recorded and fed back to his– or herself, which may help modulate depressive moods or obsessive-compulsive thoughts. "Give yourself a strict talking to" may take on an entirely new meaning.

Grau C, Ginhoux R, Riera A, Nguyen TL, Chauvat H, Berg M, Amengual JL, Pascual-Leone A, & Ruffini G (2014). Conscious Brain-to-Brain Communication in Humans Using Non-Invasive Technologies. PloS one, 9 (8) PMID: 25137064