Reading minds seems to be a common part of the
science-fiction canon—a genre much loved by actual scientists. But even as
someone who turned their love of Kurt Vonnegut, John Wyndham and H.G. Wells
into a career as a neuroscientist, I hadn’t considered telepathy a serious
avenue for research—until recently.
Lately, there’s been a lot of hype in the
neuroscience world about a technology called “brain-to-computer
interfaces,” which are electric networks which can send a
person’s brain signals to a computer. This computer can then be taught to read
these signals, and use them to perform a variety of tasks. For example,
just last year this sort of
device was used to record the movement signals in the brain of disabled stroke
patients, sending an electrical current to an upper body exoskeleton that
controlled the person’s limbs —allowing these patients to regain control over
their hands and arms.
But another promising kind of interface that
so far has received less attention is the brain-to-brain interface, or
BBI. A brain-to-brain interface records the signals in one person’s brain, and
then sends these signals through a computer in order to transmit them
into the brain of another person. This process allows the second person to
“read” the mind of the first or, in other words, have their brain fire in a
similar pattern to the original person.
Back in 2013, the first study in which two
brains were successfully joined to collaborate and complete a task
was published in Scientific Reports. First,
Miguel Pais-Vieira and his colleagues trained rats to perform a basic
task: the animals were trained to press one of two levers, with the
correct lever signalled with a light. The correct choice gave them access
to water. Once the rats could successfully complete this task four out of five
times, they were assigned as either the encoder—the one sending signals—or
the decoder, the one receiving them. Encoder rats were surgically
implanted with recording wires that measured activity in the motor areas of
their brain, while decoder rats were implanted with stimulating wires in the
same area. Each one was kept in a separate container, and only the encoder
rats were shown the light signal on the levers. As the encoder rats chose a
lever, neurons in their brain started firing.
The BBI recorded this activity, transformed it, and
used it to stimulate an equivalent pattern into the brain of the decoder rat.
The decoder rat had to correctly press a lever based on this stimulation.
(Water was only given if both animals successfully pushed the right lever.) The
researchers found that both rats pushed the correct lever 62 percent of
the time, or more than chance probability.
Within a year, applications for this kind of
device ballooned. In November of 2014, the first real-time BBI for
humans was developed by
Rajesh Rao and colleagues at the University of Washington. Unlike the poor
rats, the human device was non-invasive, meaning surgery wasn’t
required. This device transferred the movement signals from the encoder
straight to the motor area of the brain of the decoder, without using a
computer. In the study, Rao and his team used an electroencephalography
(EEG), placing recording wires on the scalp of the encoding person. Then
the scientists used transcranial magnetic stimulation (TMS) on the
decoding person’s brain, sending little magnetic pulses through their
skull to activate a specific region of their brain. This caused the
second person to take the action that the first person meant to—for example, to
press a button.
The decoder wasn’t consciously aware of the
signal they received… Instead, their hand simply moved when stimulated, as
though a puppeteer was controlling their limbs.
But, cool as this sounds, there was a
major limitation to the study. The decoder wasn’t consciously aware of the
signal they received. They weren’t able to actively process the incoming neural
information—meaning only movement was transferred, not thoughts. Instead,
their hand simply moved when stimulated, as though a puppeteer was controlling
their limbs.
Fortunately, a study using BBIs to
transfer information between people swiftly followed. The same researchers at
The University of Washington then designed a game with pairs of
participants, similar to 20 Questions. In the game, the encoder was given an
object that the decoder wasn’t familiar with. The goal was for the decoder to
successfully guess the object through a series of yes or no questions. But
unlike in 20 Questions, the encoder responded by looking LED flashing lights,
one signifying yes and the other no. The visual response generated in the encoder’s
brain was transmitted to the visual areas of the brain of the decoder.
To do so, the encoders had to wear an
electroencephalography cap, or EEG cap, which uses electrodes on the scalp to
detect brain activity. Meanwhile, the decoders had a transcranial magnetic
stimulation, or TMS apparatus, positioned above their corresponding brain area.
The TMS creates small changes in the magnetic field, which caused neuron firing
similar to that in the encoder participants. In other words, if the encoder
said yes, the decoder simply saw a flash of light. The decoders were
successfully able to guess the object in 72 percent of the games, compared
to an 18 percent success rate without the BBI. This suggests a lot of
promise for accurately transmitting information between two people.
The brilliant aspect of this study was that by
generating the transmitted signal in the visual areas of the brain, the
decoding person was consciously aware of the information given to them. This
also meant that the decoder had to actively participate, by clicking
either a yes or no button. Furthermore, this was the largest BBI study, and
also the first to include female participants.
We still can’t transmit complex ideas between
people, mainly because we still don’t know how the brain encodes
complex ideas.There is obviously still a long way to go before
we’ll know what BBI may be capable of. So far, we still can’t transmit complex
ideas between people, mainly because we still don’t know how the brain encodes
complex ideas. Weird as it may sound, science still can’t explain consciousness,
or the particular brain cells and their firing patterns that make up each
individual thought. This is what’s limiting how far we can push this
technology.
However, already this area of research is
raising ethical questions. We should start having conversations now
about the implications of these devices—before they get to the point where
we can alter complex thoughts. We need to start thinking, for example,
about how we can design this technology to prevent unwanted thoughts being sent
directly into our heads.
That said, these devices clearly have the
potential to revolutionize the way we communicate and learn. There’s a mind-boggling
number of possible applications—just imagine projecting ideas in an
educational environment, directly sharing memories with others, replacing
the need for phones or the Internet altogether, or even, in the more
near-term, using it to teach people new motor skills during
rehabilitation.
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