Are 3 brains connected via BrainNet better than one?

Experiments show brain-to-brain collaboration.

  • Scientists connect three people's brains together to play Tetris.
  • BrainNet may represent first baby steps in brain "social networking".
  • Imagine having two other people in on your most private deliberations.

The title of the paper just submitted for peer review says it all: 'BrainNet: A Multi-Person Brain-to-Brain Interface for Direct Collaboration Between Brains'. Developed by scientists from the University of Washington and Carnegie Mellon, the system passes simple signals from one person's brain to another, allowing for collaborative decisions: The first meeting of minds involved manipulating pieces in a game of Tetris. The hope is that BrainNet can, over time, be scaled up for informationally richer communication.

The BrainNet interface

The BrainNet three-person brain-to-brain interface (BBI) system combines an electroencephalography (EEG) sensor that records a signal from a Sender's brain, decodes it, and delivers it to another person's occipital cortex through a transcranial magnetic stimulation (TMS) cap. It's perceived by the Receiver as a phosphene, or a brain-produced flash. Two Senders can be connected to the same Receiver.

Credit: Jiang, et al

YES and NO choices are represented by the circles at the edge of each screen. "BCI" stands for "Brain to Computer Interface" while "CBI" is the abbreviation for "Computer to Brain Interface."

A game of Tetris for the ages

Tetris trios

The researchers recruited 15 subjects—18–35 yrs, eight female—and divided them into five trios, each of which contained two Senders and one Receiver.

The task

The experiments consisted of a single task performed multiple times: The successful completion of a single round of Tetris. As in any Tetris game, the goal was to rotate, if necessary, a slowly falling piece so that it successfully completed a row at the bottom of the screen. Both Senders offered advice—not always in agreement—to the Receiver.

During each task the Senders saw both the dropping piece and the bottom row—the Receivers saw only the dropping piece.

(Jiang, et al)

Thinking about a yes or no choice

As a piece moved downward, each Sender was presented a yes/no choice regarding whether or not the piece needed to be rotated or not. He or she was instructed to stare at either the on-screen YES or NO lights to move a cursor toward the light representing the desired choice.

(Jiang, et al)

The lights flashed at different frequencies —17 kHz per second for YES and 15 kHz for NO — allowing the EEG to use the different rates as a way of identifying the Sender's decision.

BrainNet steps in

The EEGs transmitted each YES or NO via TCP/IP to a decoder for conversion to a single TMS pulse that was then delivered to the Recipient's TMS cap. If the pulse was strong enough, a phosphene would appear to the Recipient signifying a "yes, rotate the piece" signal. If not, no phosphene would be seen, meaning, "no, don't do anything."

Unreliable help

It was up to the recipient to make a decision as to who was providing the best instructions. The researchers introduced this element as a way of assessing the extent to which recipients could filter out "noise," which is to say, worthless information.

The paper says, "To investigate whether the Receiver can learn the reliability of each Sender and choose the more reliable Sender for making decisions, we designed the system to deliberately make one of the Senders less accurate than the other. Specifically, for each session, one Sender was randomly chosen as the 'bad' Sender and in ten out of sixteen trials in that session, this Sender's decision when delivered to the Receiver was always incorrect, both in the first and second round of the trial."

Over the course of the tests, the researchers found that Recipients became quite good at tuning out their bad Senders.

(Jiang, et al)

Is this what you really want?

Once the Recipient had rotated the piece or not, the piece was displayed for the Senders hanging halfway down the screen in its current orientation. At this point, the Senders could once again send instructions to the Recipient who could then rotate it, if necessary, for the piece's final correct placement.

Encouraging results

The paper found in the end that, "Five groups, each with three human subjects, successfully used BrainNet to perform the Tetris task, with an average accuracy of 81.25%." That's pretty impressive and way above the random odds of success, as the report's figure illustrates.

(Jiang, et al)

Of course, BrainNet is just a beginning at best, dealing with extremely simple binary choices from Senders, and a fairly simple binary choice for the Recipient to make. This nothing like sharing a complex thought. The team has considered adding other, levels of exchange, perhaps via fMRI, to give greater depth to the type of information that can be sent and received. Their hope, though, is that BrainNet is an early step in the "possibility of future brain-to-brain interfaces that enable cooperative problem solving by humans using a 'social network' of connected brains."

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Yale scientists restore brain function to 32 clinically dead pigs

Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.

Still from John Stephenson's 1999 rendition of Animal Farm.
Surprising Science
  • Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
  • They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
  • The research raises many ethical questions and puts to the test our current understanding of death.

The image of an undead brain coming back to live again is the stuff of science fiction. Not just any science fiction, specifically B-grade sci fi. What instantly springs to mind is the black-and-white horrors of films like Fiend Without a Face. Bad acting. Plastic monstrosities. Visible strings. And a spinal cord that, for some reason, is also a tentacle?

But like any good science fiction, it's only a matter of time before some manner of it seeps into our reality. This week's Nature published the findings of researchers who managed to restore function to pigs' brains that were clinically dead. At least, what we once thought of as dead.

What's dead may never die, it seems

The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called BrainEx. BrainEx is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.

BrainEx pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.

The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if BrainEx can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.

As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.

The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.

"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told National Geographic.

An ethical gray matter

Before anyone gets an Island of Dr. Moreau vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.

The BrainEx solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness.

Even so, the research signals a massive debate to come regarding medical ethics and our definition of death.

Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?

"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the New York Times. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."

One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.

The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, told Nature that if BrainEx were to become widely available, it could shrink the pool of eligible donors.

"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.

It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.

Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? The distress of a partially alive brain?

The dilemma is unprecedented.

Setting new boundaries

Another science fiction story that comes to mind when discussing this story is, of course, Frankenstein. As Farahany told National Geographic: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have Frankenstein, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."

She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.

Scientists see 'rarest event ever recorded' in search for dark matter

The team caught a glimpse of a process that takes 18,000,000,000,000,000,000,000 years.

Image source: Pixabay
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