A brain–computer interface (BCI) can decipher the imagined sentences of people who have conditions that interfere with speech — and it comes with password protection to avoid revealing private thoughts. The system begins decoding users’ internal speech only after they think of a specific keyword. This internally spoken “keyword” can enable a user to “lock” and “unlock” the BCI to prevent the broadcasting of their private thoughts or spontaneous ‘self-talk’.

Excerpt from Gemma Conroy, A mind-reading brain implant that comes with password protection, Nature, Aug. 14, 2025