Agents, chatbots and other tools based on artificial intelligence (AI) are increasingly used in everyday life by many. So-called large language model (LLM)-based agents, such as ChatGPT and Llama, have become impressively fluent in the responses they form, but quite often provide convincing yet incorrect information. Researchers draw parallels between this issue and a human language disorder known as aphasia, where sufferers may speak fluently but make meaningless or hard-to-understand statements. This similarity could point toward better forms of diagnosis for aphasia, and even provide insight to AI engineers seeking to improve LLM-based agents.