Researchers have discovered that using a soft, squishy, ​​water-rich gel, you can not only play the video game Pong, but you’ll actually get better at it over time.

These findings come almost two years after brain cells in a petri dish were taught to play the 1970s classic. According to the researchers involved, the result shows “something like intelligence.”

The team behind the recent study said that while they were inspired by this work, they make no claims that their hydrogel is sentient.

“We are suggesting that it has a memory and that this memory allows it to improve its performance by accumulating experience,” said Dr. Vincent Strong, lead author of the study from the University of Reading.

Strong said the work could provide a simpler way to develop neural network algorithms – models that underlie AI systems like Chat GPT – noting that they are currently based on how biological structures work.

Pong was released in 1972 and was one of the first video games. It is based on a simple principle: two paddles on a playing field can be moved up and down to hit a ball back and forth between them. The longer the rally, the higher the score.

Strong’s study focused on a single-player version in which a racket is moved along a wall of a court to keep the ball moving.

In an article in the journal Cell Reports Physical Science, he and his colleagues describe how they sandwiched an electroactive polymer hydrogel between two plates, each carrying a 3×3 array of electrodes connected to a computer system that simulated Pong.

Six of the electrode pairs in a 3×2 arrangement were then stimulated to represent the movement of the ball within the playing field.

The team applied a small voltage to the other three pairs of electrodes – the wall where the paddle is located – and measured the current with sensors. The position of the paddle was defined as the point where the current was highest.

Crucially, the hydrogel used in the experiment contains charged ions. These move in response to electrical stimulation and stay where they land.

This meant that the point along the “wall” with the strongest current shifted with the movement of the ball, allowing the racket to change its position.

“Initially, the ions are evenly and randomly distributed, so the club sometimes hits the ball and sometimes misses,” said Strong.

But as the ball bounces across the court, the gel is increasingly electrically stimulated.

“Over time, the ion concentration increases where the ball is most present. It acts like a kind of muscle memory, because at higher concentrations there are higher currents and the club can operate more precisely,” said Strong.

In other words, the racket can hit the ball more often, resulting in longer rallies.

“Our research shows that even very simple materials can exhibit complex, adaptive behaviors typically associated with living systems or sophisticated AI,” said Dr. Yoshikatsu Hayashi, another author of the research at the University of Reading.

Dr. Brett Kagan, chief scientific officer at Cortical Labs who worked on the Pong-playing brain cells but was not involved in the recent study, said the hydrogel system demonstrates a basic form of memory, similar to the way a riverbed records a memory of flow.

This could be helpful in understanding how changes within a medium can help electrical signals to be better conducted through the medium.

However, he said that much more work is needed to demonstrate that hydrogels can “learn.”

“Performance and improvement were tied to a specific site of stimulation. When that site was changed in any way, the system could no longer reorganize and continue to perform,” Kagan said.

“This is different from our tests with neural systems, where we showed that the learning process occurred independently of the way the information was presented.”