A conversational user interface (CUI) is implemented in a computer by mimicking the organization and retrieval of linguistic memories of human conversation. To mimic the organization of linguistic memories in a human brain, the artificial memories are stored as sequences of patterns, are stored in invariant form, are organized hierarchically, and are recalled auto-associatively. To mimic the recall of linguistic memories in a human brain, the same algorithm performs the recall of the various memories. Each artificial memory is a pairing of the invariant representation and an associated responsive message. When a received utterance is determined to match the invariant representation of a memory, the memory is evoked and the associated responsive message is presented to the person.