Communication with Surprise – Computational and Neural Mechanisms for Non-Verbal Human Interactions

Communication, often grounded in shared expectations, faces challenges without common linguistic backgrounds. Our study explores how people instinctively turn to the fundamental principles of the physical world to overcome communication barriers. Specifically, through the Tacit Communication Game, we investigate how participants develop novel strategies for conveying messages without relying on common linguistic signals. We developed a new computational model built from the principle of expectancy violations of a set of common universal priors derived from movement kinetics. The model closely resembles the Sender’s messages, with its core variable – the information-theoretic surprise – explaining the Receiver’s physiological and neural responses. This is evidenced by a significant correlation with the pupil diameter, indicating cognitive effort, and neural activity in brain areas related to expectancy violations. This research highlights the adaptability of human communication, showing how surprise can be a powerful tool in forming new communicative strategies without relying on common language. ### Competing Interest Statement The authors have declared no competing interest.