The era of brain surveillance has begun. Advances in neuroscience and artificial intelligence are converging to give us an affordable and soon-to-be widely available generation of consumer neurotech devices—a catchall term for gadgets that, with the help of dry electrodes, connect human brains to computers and the ever-more-sophisticated algorithms that analyze the brain-wave data.

A version of this article appeared in the March–April 2023 issue of Harvard Business Review.