Free will and neural preparation
Separate timing in an arbitrary movement task from claims about responsibility and deliberation.
The question
Does neural activity before a reported intention show that conscious agency is an illusion?
Readiness-potential experiments became central to late twentieth-century debates about volition. They measure a narrow action, not the full range of decisions people call free.
What the claims mean
Early commitment
One interpretation treats premovement activity as evidence that an action has already been initiated before reported awareness.
Accumulation account
Schurger and colleagues model the averaged signal as a consequence of fluctuating activity approaching a movement threshold. The signal need not mark an early completed decision.
Conceptual account
Whether causally determined deliberation can count as free is a philosophical question. A timing difference does not select a definition of freedom.
Evidence to examine
Schurger, Sitt and Dehaene (2012) modeled spontaneous movement timing and the premovement buildup using a neural accumulator. Their explanation specifically concerns arbitrary, self-initiated movement near the end of the causal chain.
Shared ground and disagreement
What the accounts can share
Neural preparation occurs before movement. Reports of when an intention began are measurements that require interpretation.
What remains at issue
What the averaged readiness potential represents, and how awareness participates in choices that have reasons, alternatives and consequences.
Limits and next tests
Finger movements made at an arbitrary moment do not establish how long-term planning works. Neither a neural precursor nor a stochastic process by itself settles moral responsibility.
What would help distinguish the claims?
Contrast arbitrary and consequential choices, preregister competing timing models and use converging measures of intention. State separately what each model implies for the chosen philosophical definition.
Textbook connection
ContextualOpenStax Psychology 2e: 1.2 History of Psychology
The section provides background vocabulary. It does not cover the full debate or establish the status of later research.
Sources and access
- Schurger, A., Sitt, J. D., & Dehaene, S. (2012). An accumulator model for spontaneous neural activity prior to self-initiated movement. Proceedings of the National Academy of Sciences of the United States of America, 109(42), E2904-13. https://doi.org/10.1073/pnas.1210467109Consulted sourceAbstract inspected
Primary bibliographic record and complete abstract retrieved from Europe PMC on October 21, 2026. Full paper methods and supplements were not inspected.