MOTOR RESPONSE PROGRAMMING DURING SIMPLE AND CHOICE-REACTION TIME - THE ROLE OF PRACTICE

Reaction time (RT) before a motor response has been shown to depend on the duration or complexity of the response, indicating that responses may be programmed during RT. Some studies have reported that choice RT is influenced more than simple RT when these parameters are varied; other studies report the opposite pattern with a stronger relation for simple RT than for choice RT. The present experiments resolved this apparent discrepancy in the literature by demonstrating that the predominant effect was on choice RT when the duration of a single response component was varied and that the predominate effect was on simple RT when the number of components in a response sequence was varied. This relation for simple RT was eliminated with practice, possibly because participants learned to recode multiple-component responses into a single chunk. A two-process view of response programming seems to be necessary to account for the findings.