How Do Expectations Shape Actions? Integrating Motor Control, Decision Making, and Clinical Neuroscience

Expectations do not merely shape perception—they fundamentally structure how actions are selected, prepared, executed, and updated. Across motor control, decision making, and clinical neuroscience, converging evidence suggests that behaviour is guided by hierarchical predictions about sensory consequences, action–outcome contingencies, value, and controllability. This review integrates predictive processing, reinforcement learning, and active inference accounts to propose a stage-based framework—the Expectations Shape Action (ExSA) model—that links generalised expectations and context-specific expectations to motivation, attention, motor preparation, monitoring, and belief updating. We argue that expectations operate as precision-weighted constraints on action policies, influencing both behavioural vigour and flexibility across timescales. Distinct disturbances in expectation formation, precision control, or updating may produce similar behavioural phenotypes, including avoidance, compulsivity, psychomotor slowing, or impaired agency. By organising empirical findings across computational, neural, and clinical levels, the ExSA framework provides a mechanistic account of how predictive control governs adaptive action and how its disruption contributes to psychopathology. This synthesis highlights expectations as actionable computational targets for experimental manipulation and therapeutic intervention.