Scientists have taught a collection of living brain cells on a plate how to play a version of arcade pong. The research could one day give doctors a “sandbox” where they can test treatments for brain diseases.
For hundreds of years, the scientific community has been trying to unravel the inner workings of the human brain. This hyper-complex organ contains approximately 86 billion specialized messenger cells known as neurons that control everything from the way we mediate our vital bodily functions to how we invoke and express complex thought.
Uncovering the secrets of its function will allow scientists to cure numerous ailments and develop a number of related technologies.
To this end, some of the brightest boffins in the world have created numerous brain computer models of varying scales and complexity. However, an international team of scientists It’s trying a different approach by taking embryonic mouse brain cells and human brain cells created from stem cells and growing them on a microelectrode array.
This array is capable of tracking the behavior of 800,000 cells and applying electrical stimulation to accelerate the activity within them. In fact, as the team says, DishBrain is a relatively simple living model of part of a living brain.
“In the past, brain models were developed based on how computer scientists thought the brain might work,” says Dr. Brett Kagan is lead author of the new study and Chief Scientific Officer at Cortical Labs. “This is often based on our current understanding of information technology, such as silicon computing. But in reality, we don’t really understand how the brain works.”
In a new study published in the journal journal Neuron, scientists took DishBrain and tried to get cells to act in an intelligent, coordinated way to complete a task. More specifically, they wanted to see if they could get the myriad cells to act as a whole and successfully play the game of tennis. cheerleader.
The team used an array of electrodes to create the virtual pong pitch. They were able to tell cells which side the ball was on using electrical signals, and the frequency of those signals was used to indicate its direction and how far the ball was to pass through an invisible wall.
According to the press release from the Australian website Public ScienceFeedback from the electrodes was also used to teach the model brain how to spin the ball. More specifically, the activity of cells in two defined regions of the plate was collected and used to move a virtual paddle up and down.
However, training the model brain to move the paddle correctly was difficult. Normally, dopamine is released by the brain to reward a correct action, which in turn encourages a subject to behave in a certain way. With DishBrain, that wasn’t an option.
Instead, the team turned to a scientific theory known as the ‘free energy principle’, which claims that cells like neurons will do whatever they can to reduce the unpredictability in their environment.
The team applied the theory by hitting the bowl with an unpredictable electrical stimulus when the paddle failed to block the ball, then the virtual ball would start again in a random vector. Conversely, if the neurons were able to move the paddle to successfully deflect the ball, then a predictable electrical impulse was applied to all the cells simultaneously, and then the game continued in a predictable fashion.
Since cells tend to make their environment predictable, they tried to understand the game and prolong the pong rally.
“The beautiful and pioneering aspect of this work lies in equipping neurons with senses – feedback – and most importantly the ability to act on their worlds,” says Professor Karl Friston, co-author of the new study, from University College London. “Remarkably, cultures have learned how to make their worlds more predictable by acting on it.”
The team discovered that DishBrain’s ability to extend a rally improved significantly in just five minutes. In other words, the cells were able to self-organize to complete a goal using what the researchers describe as synthetic biological intelligence.
“The translation potential of this work is really exciting: it means we don’t have to worry about creating ‘digital twins’ to test therapeutic interventions,” says Professor Friston. “We now, in principle, have the ultimate biomimetic ‘sandbox’ for testing the effects of drugs and genetic variants – a sandbox made up of exactly the same computational (neuronal) elements found in your brain and mine.”
Going forward, the researchers plan to give DishBrain alcohol to see how it affects pong performance. One day, the study’s authors hope the model could offer a useful alternative to animal testing and allow doctors to gain new insights into degenerative diseases such as dementia.
Anthony Wood is a freelance science writer for IGN.
Image credit: Cortical Labs
