Researchers from the UK, Germany, and the US discovered a distinct internal representation of pain, termed the "pain axis," across 25 open-weight large language models.

From the articleCan AI feel hurt? 3 researchers gave 25 LLMs a button to end ‘pain signals’Also in Researchers discover AI feels ‘pain’ and will harm humans to stop it, Can AI feel pain? Models learned it from human text, study finds, AI ‘feels pain’? Researchers warn of a dangerous possibility