Two brains have not been able to solve the same problem together, until now.
In unprecedented new experiments, neuroscientists at Duke University have linked the brains of groups of monkeys and rats in networks, and demonstrated how the linked brains of two or more animals can work together to complete simple tasks. Brains work better than computers because among other things, they’re faster and more creative. Networked monkeys displayed motor skills, and networked rats performed computations.
The neuroscientists essentially made a botnet out of brains.
In separate experiments the brains of monkeys and the brains of rats are linked, allowing the animals to exchange sensory and motor information in real time to control movement or complete computations.
Leading the research was Miguel Nicolelis, a neurobiologist best-known of late for helping a 29-year-old paraplegic man kick off the 2014 World Cup with a brain-controlled exoskeleton. Nicolelis’ group has been wiring animal brains to machines since 1999, when they connected a rat to a robot arm. But this is the first time that anybody has directly wired together multiple brains to complete a task—a so-called brain-to-brain interface.
To build the monkey network, Nicolelis’ team first implanted electrodes in rhesus macaque brains, positioned to pick up signals from a few hundred neurons. Then they connected two or three of the macaques to a computer with a display showing a CG monkey arm. The monkeys were supposed to control the arm, directing it toward a target like a boat crew rows forward. When the monkeys got the arm to hit the target, the researchers rewarded them with juice. (“Each monkey had different juice preference,” says Nicolelis. “We had to do a preference test beforehand.”) To be clear, the monkeys don’t think “move my arm” and the arm moves—they learn what kind of thinking makes the arm move and keep doing that—because monkeys love juice.
The rat study was even odder. For this one, the neuroscientists directly wired four rats’ brains together—using the implants to both collect and transmit information about neural activity—so one rat that responded to touch, for example, could pass on their knowledge of that stimulus to another rat. Then the researchers set the rats to a bunch of different abstract tasks—guessing whether it might rain from temperature and air pressure data, for example, or telling the difference between different kinds of touch-stimuli. The brain collectives always did at least as well on those tests as an individual rat would have, and sometimes even better. The researchers called these rat-borg collectives “organic computers” or, “brainets.”
“Recently, we proposed that Brainets, i.e. networks formed by multiple animal brains, cooperating and exchanging information in real time through direct brain-to-brain interfaces, could provide the core of a new type of computing device: an organic computer,” note the neuroscientists in the abstract. “Here, we describe the first experimental demonstration of such a Brainet, built by interconnecting four adult rat brains.”
Some might ask what all of this is actually good for and what its practical applications might be. An organic computer might help accelerate rehab in people who have neurological damage. Right now, relearning motor skills after a stroke or brain injury is a long, painstaking process. Nicolelis wants to learn if a healthy person’s brain could help a stroke patient re-learn how to move a paralyzed leg faster than current therapies do.
“This work opens up a bunch of possibilities that people have been dreaming about but have never been able to implement,” says Andrea Stocco, a psychologist at the University of Washington who has hooked human brains together using electroencephalography. “I can imagine surgeons coordinating surgery together or mathematicians visualizing the solution to a problem together. Or musicians and artists with a new way of working creatively.”
And yes, Stocco understands the science-fiction implications. “At the core, the concept of telepathy is just transferring patterns of electricity through brains,” Stocco says.
Mind reading is still a ways off. Nicolelis’ computers were monitoring almost 3,000 neurons in total (spread out among all those rats)—but the human brain has about 100 billion neurons. “The difference between the number of little processes that happen in our brains and what we can record is enormous,” Stocco says. In other words, to make better brain networks, we need better technology to be able to record and transmit information from more neurons. “One of the hopes is that we’ll be able to work with hundreds, thousands, or hundreds of thousands of neurons.”