Predictive Errors

A predictive error is a mismatch between what the brain expects to happen (predictive coding) and what actually does. A surprise or unexpected signal travels to the brain to adjust its internal model, prompting learning and adaptation based on new information. Larger prediction errors show a greater discrepancy between expectations and reality, resulting in more significant learning updates. Prediction errors are associated with dopamine neurons that fire strongly when a reward is better than expected (positive prediction error). Hearing a sudden loud bang creates a large prediction error, so we become alert to identify the source.