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Washington (AFP) – Brain cells living in a dish can learn to play the classic video game Pong, demonstrating “intelligent and sensitive behavior”, say Australian neuroscientists in a new paper.
Brett Kagan, who led the study published Wednesday in the journal Neuron, told AFP that his findings open the door to a new type of research in which neurons could one day be used as biological information processors, in addition to digital computers.
“What machines can’t do is learn things very quickly – if you need a machine learning algorithm to learn something, it requires thousands of data samples,” he said. -he explains.
“But if you ask a human or train a dog, a dog can learn a trick in two or three tries.”
Neurons are the building blocks of intelligence in all animals, from flies to humans.
Kagan, Scientific Director of Melbourne Cortical Laboratories, attempted to answer the question of whether there is a way to harness the inherent intelligence of neurons.
To perform their experiment, Kagan and his colleagues took mouse cells from embryonic brains and derived human neurons from adult stem cells.
They then cultured them on arrays of microelectrodes capable of reading their activity and stimulating them. The experiments involved a group of around 800,000 neurons, roughly the size of a bumblebee’s brain.
In the “game”, a signal was sent from the left or right of the board to indicate where the ball was, and “DishBrain”, as the researchers called it, returned signals to move the racket, in a simplified opponent . – free version of Pong.
– “Essential, but not conscious” –
One of the main hurdles was how to “teach” neurons.
In the past, it was proposed to give them a dose of dopamine, the “feel-good” hormone, to reward correct action – but this was very difficult to achieve in practice in a time-sensitive way.
Instead, the team relied on a theory called the “free energy principle” which was coined by the paper’s lead author, Karl Friston, over a decade ago. that cells are wired to minimize the unpredictability of their environment.
When the neurons succeeded in getting the ball hit by the racket, they received a “predictable” electrical signal corresponding to success. But when they missed, they received a random or “unpredictable” electrical signal.
“The only thing neurons could do is get better at trying to hit the ball to keep their world controllable and predictable,” Kagan said.
The team thinks DishBrain is sentient – which they defined as being able to dynamically detect and respond to sensory information – but decided to call it “conscious”, which implies awareness of being.
DishBrain even tried another task – the dinosaur game that pops up in Google Chrome when no internet connection is found, and the preliminary results are encouraging, Kagan said.
For their next steps, the team plans to test how DishBrain’s intelligence is affected by drugs and alcohol – although Kagan himself is the most excited about the future possibilities of biological computers based on this fundamental discovery.
“This is interesting and robustly conducted neuroscience,” said Tara Spires-Jones of the Center for Discovery Brain Science at the University of Edinburgh, who was not involved in the study.
“Don’t worry, while these dishes of neurons can change their responses based on stimulation, they’re not SciFi-style intelligences in a dish, they’re simple circuit responses (though interesting and scientifically important ),” she added.
© 2022 AFP