Scientists have developed a system that uses brain scans and artificial intelligence (AI) to transcribe the “gist” of what people are thinking, according to a new study published in the journal Nature Neuroscience. The researchers used an fMRI machine to scan the brains of three participants who spent a total of 16 hours inside, listening to spoken narrative stories. They then used a neural network language model to predict how each person’s brain would respond to perceived speech, and narrowed down the options until it found the closest response. The system is the first to reconstruct continuous language without an invasive brain implant, and has raised concerns about mental privacy. The researchers called for regulations to protect it.