Elon Musk already has rockets, cars, AI, and humanoid robots. Musk’s rival Sam Altman runs OpenAI, the company behind the leading AI chatbot, ChatGPT. Now, both men and other billionaires want a piece of the human brain. Their latest bets on brain-computer interfaces, or BCIs, reveal less about today’s medical breakthroughs and more about a looming contest over who owns the neural on-ramp to digital life. As founders and experts in the space told Decrypt, billionaire attention “elevates the whole industry” even as it distorts priorities.