(Washington) Neurons cultured in a Petri dish are able to learn to play Pong, the great classic of video games, thus demonstrating “intelligent and sentient behavior”, according to Australian neuroscientists.
Posted at 2:20 p.m.
This study, published Wednesday in the scientific journal Neuronopens the way to a new type of research that could one day use neurons to process information, a kind of biological machines that would support digital computers, according to the researcher who conducted the research, Brett Kagan.
“Machines are incapable of learning things very quickly. For a machine learning algorithm to learn something, it needs thousands of data samples,” he explained.
While “a dog can learn a trick in two or three tries,” he notes.
Neurons are the foundation of intelligence in all animals, from insects to humans.
For their experiment, aimed at discovering whether it was possible to exploit the inherent intelligence of neurons, Brett Kagan and his colleagues took neurons from embryonic mouse brains as well as neurons from adult human stem cells.
They then cultured these neurons around arrays of microelectrodes capable of detecting their activity and stimulating them. The experiments involved clusters of about 800,000 neurons, the size of a bumblebee’s brain.
In a kind of simplified version of the tennis game Pong, a signal was then sent from the right or the left to indicate the location of a ball and the cluster of neurons, dubbed by the researchers “DishBrain” (or brain in box in French), responded with another signal to move the racket.
“Principle of Free Energy”
One of the main hurdles was figuring out how to get neurons to learn a task.
Previous work had suggested giving them a dose of the “happiness hormone” dopamine with every correct action – but this proved difficult to accomplish with the necessary speed.
Instead, the D teamr Kagan relied on the so-called “free energy principle” theory introduced more than a decade ago by Karl Friston, the lead author of the study published on Wednesday, which states that cells instinctively seek to minimize the unpredictability of their environment.
When the neurons managed to hit the ball using the racket, they therefore received predictable information indicating their success. But when they missed, the signal received was random, unpredictable.
“The only way for neurons to keep their world controllable and predictable was to be more successful at hitting the ball,” Brett Kagan detailed.
His team considers DishBrain to be “sentient” – which they define as being able to perceive sensory information and respond to it dynamically – but don’t go so far as to call it “awareness”, which implies d to be aware of one’s own existence.
This “brain in a box” has even tried the game that replaces Google’s search engine in the event of a lack of internet connection, which consists of running a dinosaur through obstacles, and the first results have been encouraging, a said Brett Kagan.
The scientists next want to test how drugs and alcohol affect the intelligence of these neurons, but the Dr Kagan is especially excited about the possibility of developing biological computers.
“It’s (a) rigorous and interesting neuroscience experiment,” said Tara Spires-Jones of the University of Edinburgh, who was not involved in the study.
“Don’t worry, even though these boxes of neurons can change their responses when stimulated, they’re not sci-fi type intelligence boxes, they’re simple (though interesting and important d ‘a scientific point of view) circuit responses,’ she reassures.