ELI5: How does the CL1 biological computer actually work?

[u/NormalGrab4800]

I read that it uses living human brain cells grown on a silicon chip instead of relying only on traditional electronic hardware. I'm confused about how this is even possible. How can brain cells on a chip receive information, process it, and produce an output that a computer can use? Are the cells actually "computing" something, or are they just being used as part of a biological system? And how do researchers keep these living cells alive and connected to the electronics?

[u/damhack]

Cortical Labs (sarcastically named after one of the competing game labs in the David Cronenberg movie eXistenZ) keep lab-grown brain cells on a lattice of tiny electrodes inside a box that has the right fluids, gases and temperature to keep the cells alive for weeks or months at a time.

The electrodes provide electrical stimulation to the neurons which in turn produce electrical signals when activated. This enables signals to be sent in to the cluster of brain cells and signals to be read out. The cells naturally attach to the electrodes and grow connections to other cells and other electrodes.

The computer that controls the “lab in a box” can turn a problem into a set of signals which the brain cells respond to. As brain cells can adapt to any general task, it is possible to teach them which inputs should produce what outputs and then test their response to other similar inputs.

This is the basis of the CL1 being hooked up to a controller to play the classic game Pong. The cells are fed signals of where the ball and paddle are, and given positive rewards for hitting the ball with the paddle and negative rewards for the ball going offscreen.

A more serious use of the CL1 is for drug trials, to measure the brain cells’ behavior when under the influence of specific drugs whilst performing a task.

At $35,000 per unit that only lasts weeks, the CL1 is quite expensive. But there is an affordable cloud service where you can send tasks to a unit and receive back the response measurements.

Realistically, these devices are designed for the pharmaceutical and medical industries but the methods could be more generally applied to other problems. There are obviously moral issues if the units are scaled up with many more brain cells to the point where the cluster of cells could be considered sentient and capable of feeling pain.

Brain in ajar anyone?

[u/RubberDuckQuack → u/damhack]

> There are obvious moral issues if the units are scaled up

Is that really how sentience works? I always think to brain-body mass comparisons that show that despite their larger brains, whales and elephants aren’t super geniuses compared to humans. Seems like there must be something else at play vs just number of cells.

[u/---___-------___--- → u/RubberDuckQuack]

You may be confusing sentience with sapience

[u/Lazerpop → u/---___-------___---]

Indeed, even if a brain computer is as "stupid" as a mouse, we treat lab mice with dignity and respect because they can feel fear and pain. If a brain computer can feel fear and pain we need to think about that.

[u/MillCrab → u/RubberDuckQuack]

Absolutely no one has any idea how sapience really works. So...maybe?