July 1, 2019
UW News
Telepathic communication might
be one step closer to reality thanks to new research from the University of
Washington. A team created a method that allows three people to work together
to solve a problem using only their minds.
In BrainNet, three people play
a Tetris-like game using a brain-to-brain interface. This is the first
demonstration of two things: a brain-to-brain network of more than two people,
and a person being able to both receive and send information to others using
only their brain. The team published its results April
16 in the Nature journal Scientific
Reports, though this research previously attracted media attention after
the researchers posted it September
to the preprint site arXiv.
“Humans are social beings who
communicate with each other to cooperate and solve problems that none of us can
solve on our own,” said corresponding author Rajesh Rao, the CJ
and Elizabeth Hwang professor in the UW’s Paul G. Allen School of Computer
Science & Engineering and a co-director of the Center for Neurotechnology. “We wanted to
know if a group of people could collaborate using only their brains. That’s how
we came up with the idea of BrainNet: where two people help a third person
solve a task.”
As in Tetris, the game shows a
block at the top of the screen and a line that needs to be completed at the
bottom. Two people, the Senders, can see both the block and the line but can’t
control the game. The third person, the Receiver, can see only the block but
can tell the game whether to rotate the block to successfully complete the
line. Each Sender decides whether the block needs to be rotated and then passes
that information from their brain, through the internet and to the brain of the
Receiver. Then the Receiver processes that information and sends a command — to
rotate or not rotate the block — to the game directly from their brain,
hopefully completing and clearing the line.
The team asked five groups of
participants to play 16 rounds of the game. For each group, all three
participants were in different rooms and couldn’t see, hear or speak to one
another.
The Senders each could see the
game displayed on a computer screen. The screen also showed the word “Yes” on
one side and the word “No” on the other side. Beneath the “Yes” option, an LED
flashed 17 times per second. Beneath the “No” option, an LED flashed 15 times a
second.
“Once the Sender makes a
decision about whether to rotate the block, they send ‘Yes’ or ‘No’ to the
Receiver’s brain by concentrating on the corresponding light,” said first
author Linxing
Preston Jiang, a student in the Allen School’s combined bachelor’s/master’s
degree program.
The Senders wore
electroencephalography caps that picked up electrical activity in their brains.
The lights’ different flashing patterns trigger unique types of activity in the
brain, which the caps can pick up. So, as the Senders stared at the light for their
corresponding selection, the cap picked up those signals, and the computer
provided real-time feedback by displaying a cursor on the screen that moved
toward their desired choice. The selections were then translated into a “Yes”
or “No” answer that could be sent over the internet to the Receiver.
“To deliver the message to the
Receiver, we used a cable that ends with a wand that looks like a tiny racket
behind the Receiver’s head. This coil stimulates the part of the brain that
translates signals from the eyes,” said co-author Andrea
Stocco, a UW assistant professor in the Department of Psychology and the
Institute for Learning & Brain Sciences, or I-LABS. “We essentially ‘trick’
the neurons in the back of the brain to spread around the message that they
have received signals from the eyes. Then participants have the sensation that
bright arcs or objects suddenly appear in front of their eyes.”
If the answer was, “Yes,
rotate the block,” then the Receiver would see the bright flash. If the answer
was “No,” then the Receiver wouldn’t see anything. The Receiver received input
from both Senders before making a decision about whether to rotate the block.
Because the Receiver also wore an electroencephalography cap, they used the
same method as the Senders to select yes or no.
The Senders got a chance to
review the Receiver’s decision and send corrections if they disagreed. Then,
once the Receiver sent a second decision, everyone in the group found out if
they cleared the line. On average, each group successfully cleared the line 81%
of the time, or for 13 out of 16 trials.
The researchers wanted to know
if the Receiver would learn over time to trust one Sender over the other based
on their reliability. The team purposely picked one of the Senders to be a “bad
Sender” and flipped their responses in 10 out of the 16 trials — so that a
“Yes, rotate the block” suggestion would be given to the Receiver as “No, don’t
rotate the block,” and vice versa. Over time, the Receiver switched from being
relatively neutral about both Senders to strongly preferring the information
from the “good Sender.”
The team hopes that these
results pave the way for future brain-to-brain interfaces that allow people to
collaborate to solve tough problems that one brain alone couldn’t solve. The
researchers also believe this is an appropriate time to start to have a larger
conversation about the ethics of this kind of brain augmentation research and
developing protocols to ensure that people’s privacy is respected as the
technology improves. The group is working with the Neuroethics team at
the Center for Neurotechnology to address these types of issues.
“But for now, this is just a
baby step. Our equipment is still expensive and very bulky and the task is a
game,” Rao said. “We’re in the ‘Kitty Hawk’ days of brain interface
technologies: We’re just getting off the ground.”
See a related story from NPR.
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