Scientists have, for the first time, assisted two human beings in communicating through mental processes across two continents. They reported the results of their experiment in PLOS ONE on August 19, 2014. But if this exciting first step has your mind racing with ideas of telepathy, freely reading the streams of thoughts of your fellow human beings, hold on: for now, the current brain-to-brain experiment amounts more to a painstaking conversation in Morse code. It also raises crucial ethical issues with respect to the privacy of our mental processes and our sense of agency.
In the experiment, the researchers, based in Spain and France, used a brain-computer interface to allow a human ‘emitter’ to encode a message, and a computer-brain interface so that ‘receivers’ could decode it. The emitter, located in India, generated a message (a binary form of the word ‘hello’) by thinking of either of two things: moving their feet or their hands. The researchers used EEG to differentiate the electrical activity generated by the brain in these two situations, allowing them to translate the emitter’s thoughts into a binary code (0 when the emitter thought of moving the feet, 1 for the hands) that was sent to France over the internet. There, the receivers sat underneath a transcranial magnetic stimulation (TMS) system that transmitted the binary code to them through noninvasive brain stimulation.
TMS delivers brief but intense magnetic fields to the brain through the skull, transiently modifying its activity. When TMS is applied to the motor cortex, for instance, muscles in the arm twitch; when applied to the visual cortex in the occipital lobe, TMS causes the subject to perceive a flash of light called phosphene. The research team here chose the latter: the binary code sent from India was thus translated into TMS pulses that either induced phosphenes or not in the receivers. The receivers then simply announced whether or not they had perceived a phosphene, deciphering the binary word one bit at a time.
This experiment represents the first time that people exchanged information by consciously controlling and monitoring their own mental processes, without any active motion or actual sensory perception. Limitations on the technology that is currently available to stimulate the brain noninvasively made the process slow and not entirely error-proof: it took about 30 seconds for a single bit of information to be transmitted, and the error rate was 5 to 10%. Additionally, the message was written in a binary code not directly understandable by humans. Nevertheless, this experiment is an exciting first step towards the possibility of someday accessing the mental processes of another human being—and also, perhaps, of controlling them.
As such, this experiment raises perhaps more than its fair share of critical ethical questions. As mentioned above, noninvasive stimulation of the motor cortex triggers involuntary movements. Dr. Giulio Ruffini, the corresponding author, explains that his team chose not to stimulate the motor cortex because the receivers would then have been able to detect the communication via their peripheral nervous system (they would have sensed their own involuntary motion by proprioception), and the information exchange would therefore not have been a purely ‘brain-to-brain’ one. Nevertheless, the current research introduces the possibility that one human’s thoughts could control another human’s actions remotely, as if it were a puppet or a robot. Of course, current brain stimulation technologies are far too crude yet, but it is arguably only a question of time and of refining our understanding of motor planning and execution before we can consider such an experiment.
More generally, the idea of remotely accessing and influencing another person’s private thoughts is as chilling as it is exciting, and the current research affords a peek into this Pandora’s box. As Dr. Ruffini puts it, “technology empowers us for good and ill.” Neuroscientists will have to maintain the highest ethical standards in pursuing this line of research. They will also need the help of experts in disciplines such as computer security to ensure that the information exchanged remains protected from undesirable attention or interference. But the most profound impact of the current study might lie elsewhere: Dr. Ruffini reveals that “the original project behind this research was called HIVE”, in reference to “super-organisms in which individuals act as a collective.” Neuroscience research, more than any other, has the potential to fundamentally alter the organization of our social structures.
Grau, C., Ginhoux, R., Riera, A., Nguyen, T., Chauvat, H., Berg, M., Amengual, J., Pascual-Leone, A., & Ruffini, G. (2014). Conscious Brain-to-Brain Communication in Humans Using Non-Invasive Technologies PLoS ONE, 9 (8) DOI: 10.1371/journal.pone.0105225