Research has found that human brain cells exhibit intelligence even outside the body.

Release date:

2023-09-20

Neurons from humans and mice learned to play the video game Pong in a single dish. For the first time, the research team demonstrated that 800,000 brain cells cultured in a petri dish can perform goal‑directed tasks, showing that even neurons grown in vitro possess intrinsic cognitive capabilities and can adapt their behavior over time. This study holds significant implications for disease modeling, drug discovery, and expanding our understanding of how the brain functions and how intelligence emerges.
　　
　　“From worms to flies to humans, neurons represent the starting point of general intelligence,” said Brett Kagan, the paper’s first author and Chief Scientific Officer at the Melbourne Cortex Lab in Australia. “So the question is: can we somehow interface with neurons to harness this intrinsic form of intelligence?”
　　
　　In the experiment, the research team isolated brain cells from both mouse embryos and human stem cells, then cultured them on microelectrode arrays capable of both stimulating the cells and recording their activity.
　　
　　First, the researchers connected these neurons to a computer, enabling them to receive feedback on whether the paddle in the game was hitting the ball. They then used an electrode probe to monitor the neurons’ activity and their responses to this feedback.
　　
　　The more often a neuron moves the racket and strikes the ball, the stronger the “spikes” recorded by the electrode probe. When a neuron makes a mistake, its behavior is “criticized” by software developed in the cortical laboratory. This demonstrates that neurons can operate in a goal‑directed manner in real time, adapting to a constantly changing environment.
　　
　　“When unpredictable stimuli are applied to the cells, the system as a whole reorganizes its activity to play the game more effectively and minimize random responses,” Kagan said.
　　
　　The theory underlying this type of learning is rooted in the free-energy principle. In essence, it posits that the brain adapts to its environment by updating its model of the world or modifying its behavior, thereby better aligning with the surrounding reality.
　　
　　Researchers state that this new capability to train cell cultures to perform tasks that exhibit intelligence opens up promising avenues for future applications, with far-reaching implications for technology, health, and society. Moreover, these findings enhance the prospects of developing alternatives to animal testing when evaluating the responses of novel drugs or gene therapies in dynamic environments.