@jesus's comment on 'Living brain-cell biocomputers are now training on dopamine :marseylaptop:'

https://newatlas.com/computers/finalspark-bio-computers-brain-organoids/

Current AI training methods burn colossal amounts of energy to learn, but the human brain sips just 20 W. Swiss startup FinalSpark is now selling access to cyborg biocomputers, running up to four living human brain organoids wired into silicon chips.

The human brain communicates within itself and with the rest of the body mainly through electrical signals; sights, sounds and sensations are all converted into electrical pulses before our brains can perceive them. This makes brain tissue highly compatible with silicon chips, at least for as long as you can keep it alive.

For FinalSpark's Neuroplatform, brain organoids comprising about 10,000 living neurons are grown from stem cells. These little balls, about 0.5 mm (0.02 in) in diameter, are kept in incubators at around body temperature, supplied with water and nutrients and protected from bacterial or viral contamination, and they're wired into an electrical circuit with a series of tiny electrodes.

These two-way electrodes can send pulses of electricity into the brain organoids, and they can also measure the responses coming out of them. And that's really all you need to start taking advantage of nature's greatest computing machines; neurons habitually search for patterns, seeking order and predictability.

You can create a virtual environment for them, complete with the capability to perform actions and perceive the results, solely using electrical stimulation. You can reward them with predictable stimuli and 'punish' them with chaotic stimuli, and watch how quickly they rewire themselves to become adept at orienting themselves toward those rewards.

We've written before about computer chips with integrated brain cells – notably the Australian DishBrain device by Cortical Labs, which uses 800,000 human brain cells grown onto silicon chips. DishBrain managed to learn to play Pong within about five minutes, and has demonstrated impressive capabilities as a super-efficient machine learning tool, even drawing in military funding for further research.

The FinalSpark team uses smaller organoids, wired into arrays, and it also adds a new wrinkle, in the ability to flood the organoids with reward hormones like dopamine when they've done a good job.

"We encapsulate dopamine in a molecular cage, invisible to the organoid initially," co-founder Dr Fred Jordan told Techopedia last year. "When we want to ‘reward' the organoid, we expose it to specific light frequencies. This light opens the cage, releasing the dopamine and providing the intended stimulus to the organoid."