Response programming, as assessed by reaction time, does not establish commands for particular muscles

In previous studies, response programming has been inferred from a relation between reaction time and the nature of the response which follows. However, it has not been clear whether this programming process generates commands for specific muscles or abstract timing networks which can be applied to any appropriate muscle group. Experiment 1 employed the Sternberg (1969) additive-factor method to show that muscle selection need not be completed before such programming begins, a conclusion which is inconsistent with the view that this process establishes commands to previously selected muscles. Experiments 2 and 3 provide converging evidence against the muscle-specific view of programming by showing that advance programming of response timing can occur when the response muscle is not specified. A theoretical framework encompassing these and previous results is proposed.