Muotri and her research team had been trying to coax human stem cells to recreate tissue found in the brain's cortex, which is devoted to cognition and interpreting sensory information.
During this growth period, Muotri's team monitored the mini-brain electrical activity through EEG readings.
Specifically, the brain organoids showed a strong resemblance to infants born prematurely at 25–39 weeks post-conception.
Researchers know so little about how the human infant's brain forms during these crucial growth periods.
It's completely possible that the organoids are missing the components that drive EEG growth in humans and that the electric readings are accidental.