In September 2020 Nicholas underwent an eight-hour-long operation where doctors implanted a 1.3 millimeter probe, wide as a grain of sand, in the cerebellum of his brain.

Source: https://universe.byu.edu/2023/08/17/good-news-thursday-stroke-survivor-regains-movement-following-brain-implant-trial-couple-gets-engaged-at-finish-line-following-half-marathon/?utm_source=rss&utm_medium=rss&utm_campaign=good-news-thursday-stroke-survivor

We also have seen robots that display the kind of fluid motion controlled by 56 billion neurons in the cerebellum (the part of the human brain responsible for muscular coordination).

Source: https://venturebeat.com/ai/the-gradual-march-to-agi/