Pain affects the way people behave. For professional athletes, changes in the way actions are executed can have costly consequences (e.g. losing a tennis match in a grand slam). In this study, we examined the effects of pain expectation on movement initiation and execution when participants knew - simple reaction time (RT) task - or not - choice RT task - whether their next movement would be painful. Participants responded to the appearance of a target with a ballistic isometric wrist contraction. Simple and choice RT tasks were performed in two separate blocks in random order. In one block of trials, a painful electrotactile stimulus was delivered to the index finger when participants moved in one predetermined direction but not the other.
