Brain-to-brain interfaces

Written December 2014

It’s no Vulcan mind meld, but brain-to-brain interfaces (BBI) have been achieved, allowing for direct communication from one brain to another without speech. The interactions can be between humans or between humans and animals.

In 2014, researchers at the University of Washington performed a BBI experiment that allowed a person to gain command over another person about half a mile away, the goal being the simple task of moving their hand (communication so far has been one-way in that one person sends the commands and the other receives them). Using an electroencephalography (EEG) machine that detects brain activity in the sender and a transcranial magnetic stimulation coil that controls movement in the receiver, we’ve achieved a BBI twice – in 2014 scientists also transmitted words from brain to brain across 5,000 miles. In 2013, Harvard researchers led by Seung-Schik Yoo developed the first interspecies brain-to-brain interface, retrieving a signal from a human’s brain (generated by staring at a flashing light) and transmitting it into the motor cortex of a sleeping rat, causing the rodent to move its tail.

The ethical issues are myriad. What kind of neurosecurity can we put in place to protect individuals from having accidental information shared or removed from their brains (especially by hackers)? If two individuals share an idea, who is entitled to claim ownership? Who is responsible for the actions committed by the recipient of a thought if a separate thinker is dictating the actions?


Brain-to-Brain Interfaces: The Science of Telepathy
A good lay introduction, despite the sensational headline. The studies referred to in this summary are linked below.

(Animal-animal) A Brain-to-Brain Interface for Real-Time Sharing of Sensorimotor Information (Nature)
Description of the coupling of two rat brains. The encoder rat performed a task, and scientists transferred samples of its intracortical activity (using intracortical microstimulation (ICMS)) to a decoder rat, who learned to make similar behavioral selections.

(Human-human) A Direct Brain-to-Brain Interface in Humans (PLOS ONE)
A write-up of the study at UW-Seattle on BBI between three pairs of humans using a combination of electroencephalography (EEG) and transcranial magnetic stimulation (TMS).

  • Conscious Thought Transfer Between Two Humans (PLOS ONE)
    Results of an international study (France, Spain, US) showing that brain-computer and computer-brain interface technologies can be combined to produce computer-mediated brain-to-brain (B2B) communication between human subjects (hyperinteraction).

(Human-animal) Non-Invasive Brain-to-Brain Interface (BBI): Establishing Functional Links between Two Brains(PLOS ONE)
Details of a study that achieved a functional link between the brains of a human and a Sprague-Dawley rat.

Ethical implications of BBI:

When “I” Becomes “We”: Ethical Implications of Emerging Brain-to-Brain Interfacing Technologies (Frontiers in Neuroengineering)
One of the relatively few articles describing the ethical issues we should consider as we perfect the technology of transferring information between two brains.

What Will This Do To Me and My Brain? Ethical issues in Brain-to-Brain Interfacing (Frontiers in Systems Neuroscience)
Discussion of the implications that brain-to-brain interfaces may have on the recipient side.

Neuroethics Journal Club: The Ethical Issues behind Brain-to-Brain Interface (BTBI) Technologies (Neuroethics Blog)
A blog post from Emory University’s Neuroethics Blog, hosted by the Center for Ethics, Neuroethics Program. It is the official blog of the American Journal of Bioethics Neuroscience.

Brain-to-computer (or brain-to-machine) interface is a precursor to BBI technology. This issue appeared on the 2014 Reilly Center List of Ethical Dilemmas and Policy Issues in Science and Technology.