Lab-Made Mini Brains Produce Brain Waves Just Like Those of Preterm Babies
... While the cells were dividing and differentiating, they eventually began to "self-organize into something that resembles the human cortex," Muotri said. The cortex is the outer layer of the brain, which plays an important role in consciousness. ...
... After a couple more months of development, the brains fired signals at different frequencies and more regularly, indicating more-complex brain activity, Muotri said.... The scientists then fed the brain wave patterns from the mini brains into the algorithm and found that after 25 weeks of mini brain development, it could no longer distinguish the data coming from the human brain from that deriving from the lab-grown brain. ...
... While a human embryo is connected to the mother and thus receives signals from the outside, these lab-grown brains aren't connected to anything. "These cells have no input or no output they cannot recognize anything happening in the world," Hartung said. So they are "definitely not" conscious.
That's what most scientists would agree on, but "it's hard to say," Muotri said. "We neuroscientists don't even agree [on] what are the measurements that one can do to actually probe to see if they're conscious or not."
The human brain sends its signals to help us interact with our environment. For example, we look at a bug, the eyes send signals to brain cells, which signal to each other and let us know that we are seeing a bug. ...
https://www.livescience.com/mini-lab...uce-waves.html