A group of Australian scientists taught a collection of lab-grown brain cells in a dish to play the 1970s video game Pong.
This is the first display that a group of lab-grown brain cells can effectively be taught to perform goal-oriented tasks, the researchers, whose findings were published in the journal Neuron, reported. The scientists call the collection of 800,000 brain cells “DishBrain.”
“DishBrain offers a simpler approach to test how the brain works, and gain insights into debilitating conditions such as epilepsy and dementia,” said Dr. Hon Weng Chong, CEO of biotech start-up Cortical Labs, according to U.S. News & World Report.
To create the DishBrain, a layer of living neurons is grown on a silicon chip that interacts with a computer. The chip can deliver electric signals from the DishBrain to the computer and vice versa.
To experiment with the brain cells’ ability to learn tasks, the scientists taught the DishBrain to play the vintage video game Pong. The brain cells were taught how to play Pong using electrodes to signal to the brain cells where the balls and paddles were located during a round. The computer also collected data coming from the cells in electrical pulses.
As scientists attempted to teach DishBrain Pong, they realized DishBrain lacked motivation to play. To motivate the cells, scientists rewarded DishBrain’s good movements with an organized burst of electrical energy. When DishBrain made a mistake, scientists sent a wave of white noise.
“If they hit the ball, we gave them something predictable,” said Brett Kagan, an author of the study and chief scientific officer at Cortical Labs in Melbourne, Australia, per NPR. “When they missed it, they got something that was totally unpredictable.”
The scientist’s strategy came from the Free Energy Principle, which says that brain cells want a predictable environment — they prefer predictable stimulation like the burst of electrical energy over the unpredictable waves of white noise.
The strategy proved successful. DishBrain cells learned to produce patterns of electrical energy that allowed them to move the paddle behind the ball and hit it. The more DishBrain played, the more it improved — although DishBrain never got very good at Pong.
“They changed their activity in a way that is very consistent with them actually behaving as a dynamic system,” said Kagan. “For example, the neurons’ ability to change and adapt their activity as a result of experience increases over time, consistent with what we see with the cells’ learning rate.”
Scientists from this research hope to test how DishBrain’s Pong ability is impacted by medicine and alcohol next.