Visual representation of the simulated Pong environment where neuron activity is reflected in the tiles growing in height. Credit: Cortical Labs.
For the first time, scientists have shown that brain cells living in a dish can exhibit inherent intelligence, even modifying their behavior over time.
In a new study published in Neuron, a multi-institutional team showed that 800,000 brain cells living in a dish, aptly named DishBrain, can perform goal-directed tasks—in this case by playing the classic computer game Pong.
“This is the start of a new frontier in understanding intelligence,” said first author Brett Kagan, chief scientific officer at Cortical Labs (Australia). “It touches on the fundamental aspects of not only what it means to be human but what it means to be alive and intelligent at all, to process information and be sentient in an ever-changing, dynamic world.”
To perform the experiment, the research team took mouse cells from embryonic brains as well as some human brain cells derived from stem cells and grew them on top of microelectrode arrays that could both stimulate them and read their activity. In this way, the neurons received feedback on whether their in-game paddle was hitting the ball.
The researchers monitored the neuron’s activity and responses to this feedback using electric probes that recorded “spikes” on a grid. The spikes got stronger the more a neuron moved its paddle and hit the ball. When neurons missed, their playstyle was critiqued by a software program created by Cortical Labs. This demonstrated that the neurons could adapt activity to a changing environment in a goal-oriented way in real-time.
“The beautiful and pioneering aspect of this work rests on equipping the neurons with sensations—the feedback—and crucially the ability to act on their world,” said co-author Karl Friston, a theoretical neuroscientist at University College London. “The cultures learned how to make their world more predictable by acting upon it. This is remarkable because you cannot teach this kind of self-organization because, unlike a pet, these mini brains have no sense of reward and punishment.”
While scientists have, for some time, been able to mount neurons on multi-electrode arrays and read their activity, this is the first time cells have been stimulated in a structured and meaningful way. According to the research team, that’s because past models of the brain have been developed based on how computer scientists think the brain works—not how it actually does, which Kagan says scientists still don’t fully understand.
Even so, since the DishBrain is a living model built from basic structures, it outputs real brain function rather than flawed analogous models.
“DishBrain offers a simpler approach to test how the brain works and gain insights into debilitating conditions, such as epilepsy and dementia,” said Hon Weng Chong, CEO of Cortical Labs.
Indeed, the results of this work have potential in disease modeling, drug discoveries, and expanding the current understanding of how the brain works and how intelligence arises.
For their part, Kagan and his team will next experiment to see what effect alcohol has when introduced to DishBrain. The team plans to create a dose response curve with ethanol—essentially, get the cells “drunk” and see if they play the game more poorly, which is the typical human response when intoxicated.
The findings also raise the possibility of creating an alternative to animal testing when investigating how new drugs or gene therapies respond in dynamic environments.
“The translational potential of this work is truly exciting: it means we don’t have to worry about creating digital twins to test therapeutic interventions,” said UCL neuroscientist Friston. “We now have, in principle, the ultimate biomimetic ‘sandbox’ in which to test the effects of drugs and genetic variants—a sandbox constituted by exactly the same computing elements found in your brain and mine.”
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