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Neuroethics Journal Club: The Ethical Issues behind Brain-to-Brain Interface (BTBI) Technologies

The first Neuroethics Journal Club of the Fall 2013 semester was a discussion led by graduate student John Trimper on the ethical implications behind brain-to-brain interface (BTBI) technologies. John introduced the topic by presenting the experimental details and results from a recent paper, published by the Nicoleis lab at Duke University (Vieira et al.), where researchers utilized a BTBI to transfer sensorimotor information between two rats. The BTBI technology allowed for a transfer of information from an “encoder” rat to a “decoder” rat, not using typical bodily interactions, but instead through intracortical microstimulation (ICMS).

“Rodent Mind Meld” (Via Wired)

The researchers conducted three experiments that demonstrated an artificial communication channel where cortical sensorimotor signals, coded for a specific behavioral response, were recorded in the encoder rat and transmitted to the decoder rat. Once received from the encoder rat, the decoder rat was instructed by these signals in making behavioral choices.  In the first experiment, a motor task, the encoder rat pressed one of two levels indicated by a LED light. This information was transferred via ICMS to the decoder rat, who would then choose the same lever without the help of the LED light. While the encoder rat performed better than the decoder rat, the decoder rat did perform correctly at levels significantly above chance. In the second experiment, the decoder rat again performed significantly better than chance, but in a tactile discrimination task. The encoder rats were trained to discriminate the size of an aperture with their whiskers; if the aperture were narrow, then the rats would nose poke on the left, while if the aperture were wide, the rats would nose poke on the right. Encoder rats explored the aperture, nose poked the right or the left, and then again, through ICMS, this information was sent to the decoder rat. The decoder rat would then also poke to the right or the left, but without any hint about the size of the aperture. Not only did researchers conduct this experiment with encoder and decoder rats residing in the same Duke laboratory, but impressively the same tactile discrimination task was also completed with an encoder rat in Brazil and a decoder rat at Duke, showing the potential of long-distance BTBI technology.

The authors state at the end of the paper (Vieira et al.) that “multiple reciprocally interconnected brains,” as opposed to the dyad formed by one encoder rat and one decoder rat, would represent the “first organic computer capable of solving heuristic problems that would be deemed non-computable by the general Turing-machine,” and there is no doubt that this research is at the forefront of BTBI technology. While many of the mass media outlets sensationalized this story with headlines like “Two rats, thousands of miles apart, cooperate telepathically via brain implant” (NBC News) or “Rodent Mind Meld: Scientists Wire Two Rats’ Brains Together” (Wired), many of the journal club audience members were a bit more skeptical regarding the experimental details and the immediate consequences of the research on society. It was pointed out by more than one member of the audience that the decoder rat making the correct lever or nose poke choice was not a result of direct communication from the encoder rat, but instead was due to conditioning resulting from the training program. Both the encoder rat and the decoder rat underwent extensive training before being connected and allowed to communicate through ICMS. Potential encoder and decoder rats were first trained to respond to either the LED visual stimulus or the width of the aperture, the tactile stimulus, until 95% accuracy was reached. Rats then chosen for the decoder position underwent further training after being implanted with microstimulation electrodes; these mice were trained to recognize that multiple ICMS pulses were associated with the right lever/left nose poke, whereas a single ICMS pulse was associated with the left lever/right nose poke. When the encoder rat chose the right lever over the left lever, the decision was sent by ICMS to the encoder rat, where the encoder rat would perceive multiple ICMS pulses, a sequence that the animal had already been trained to associate with the right lever. It was generally agreed that the decoder rat’s choice is not completely due to a “mindmeld” like popular media would suggest, but also involves the rat’s ability to perceive a difference in stimulation.

The encoder and decoder rats (Pais-Vieira et al.)

Even if directly transferring complex thoughts among individuals will remain science fiction for now, this research and other experiments, such as the BTBI between a human and rat (Yoo et al.), are important because of the numerous ethical issues that accompany BTBI. BTBI takes brain-machine interface (BMI) to a new level, and for that reason, BTBI is already associated with multiple ethical issues, such as the likelihood of the extraction of incidental information, neurosecurity to protect individual neural mechanisms, and the potential of hacking. Since BTBI is a direct transfer of thoughts though, BTBI takes many ethical issues to a new level as well, and journal club took time to discuss many of these concerns. If two individuals are sharing ideas, then does a collective identity result? Who is responsible for the actions committed by the decoder if the encoder is on the other end of the communication line dictating the decoder’s moves? If responsibility for any decision is shared or not, does the encoder or the decoder have ownership over any ideas? In an ideal situation, the communication line would never be flawed, but what if the computer’s algorithm made a mistake and the wrong information was transferred? Many of these questions were framed for a discussion involving a military scenario: The encoder is a soldier, completely removed from combat, but still with a complete view of the battlefield, and the decoder is an active duty military personnel physically experiencing the fighting. A friendly fire ensues and the decoder kills a fellow solider due to the transfer of information from the encoder. Who should be held accountable for the kill – the decoder, encoder, or the scientists responsible for BTBI military setup? This kind of long-distance combat could also lead to new and complex forms of PTSD for the decoder and the encoder, which could potentially require new research and treatments. After discussing many of these questions, it was agreed that not only will many more scientific breakthroughs have to accompany the transition from the current BTBI set-up with rats pushing levers or nose poking to a militaristic BTBI, but so will many more important ethical discussions and decisions. Perhaps BTBI is a novel form of social interaction as well, and in the future, journal club meetings with powerpoints and spoken dialogue will become archaic – we will instead use BTBI to communicate and transfer the material.


Trimper, J. (2013). Let’s Put Our Heads Together and Think About This One: A Primer on Ethical Issues Surrounding Brain-to-Brain Interfacing. The Neuroethics Blog. Retrieved on October 1, 2013, from

Pais-Vieira, M., Lebedev, M., Kunicki, C., Wang, J., & Nicolelis, M.A.L. (2013). A Brain-to-brain interface for real-time sharing of sensorimotor information. Scientific Reports, 3, 1319.

Subbaraman, N. (2013). Two rats, thousands of miles apart, cooperate telepathically via brain implant. NBC News Science. Retrieved on October 1, 2013, from

Miller, G. (2013). Rodent Mind Meld: Scientists Wire Two Rats’ Brains Together. Wired. Retrieved on October 1, 2013, from

Yoo, S-S., Kim, H., Filandrianos, E., Taghados, S.J., Park, S. (2013). Non-Invasive Brain-to-Brain Interface (BTBI): Establishing Functional Links between Two Brains. PLoS ONE, 8(4), e60410.

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Strong, K. (2013). Neuroethics Journal Club: The Ethical Issues behind Brain-to-Brain Interface (BTBI) Technologies. The Neuroethics Blog. Retrieved on
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