‘Sentient’ brain cells in a bowl learn to play video games: study

Brain cells living in a bowl can learn to play the classic video game pong, demonstrating “intelligent and sentient behavior,” Australian neuroscientists argue in a new paper.

Brett Kagan, who led the study published Wednesday in the journal neurontold 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 that complement digital computers.

“What machines can’t do is learn things very quickly – if you need a machine learning algorithm to learn something, it takes thousands of data samples,” he explained.

“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, the scientific director of Melbourne-based Cortical Labs, set out to answer the question of whether there is a way to harness the inherent intelligence of neurons.

To conduct their experiment, Kagan and colleagues took mouse cells from embryonic brains and derived human neurons from adult stem cells.

They then grew them on microelectrode arrays that could read their activity and stimulate them. The experiments involved a cluster 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 side of the array to indicate where the ball was, and “DishBrain,” as the researchers called it, fired back signals to move the racquet in a simplified opponent -Free version of Pong.

“Sentient but not conscious”

One of the biggest hurdles was figuring out how to “teach” the neurons.

In the past it has been suggested that giving them a shot of the ‘feel good’ hormone dopamine to reward correct action has been very difficult to achieve in practice in a time sensitive manner.

Instead, the team relied on a theory called the “free energy principle,” coined more than a decade ago by the paper’s senior author Karl Friston, which states that cells are hardwired to minimize unpredictability in their environment.

If the neurons managed to get the racquet to hit the ball, they received a “predictable” electrical signal corresponding to success. But when they missed, they were sent a random or “unpredictable” electrical signal.

“The only thing the neurons could do is get better at hitting the ball to keep their world controllable and predictable,” Kagan said.

The team believes that DishBrain is sentient – which they defined as being able to sense and respond to sensory information in a dynamic way – but drew the line of calling it “conscious,” which is what it is Consciousness of being implies.

DishBrain even tried another task – the dinosaur game that appears in Google Chrome when no internet connection is found, and the preliminary results were 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 most excited about the future possibilities of biological computers based on this fundamental discovery.

“This is well-executed, interesting neuroscience,” said Tara Spiers-Jones of the Center for Discovery Brain Science at the University of Edinburgh, who was not involved in the study.

“Don’t worry, although these dishes of neurons can change their responses based on stimulation, they’re not SciFi-style intelligence in a dish, they’re simple (albeit interesting and scientifically important) circuit responses,” she added.

© 2022 AFP