Tal Sharf (right, senior author), Tjiste van der Molen (middle, postdoctoral researcher), and Greg Kaurala (left, staff researcher). Humans have long wondered when and how we begin to form thoughts.

Researchers in Japan built a miniature human brain circuit using fused stem-cell–derived organoids, allowing them to watch the thalamus and cortex interact in real time. They found that the thalamus ...

Lab-grown “reductionist replicas” of the human brain are helping scientists understand fetal development and cognitive disorders, including autism. But ethical questions loom. Brain organoids, which ...