Contributions of response selection processes to the response interference effect

In choice reaction-time tasks, the finding that reaction times are faster when the pair of finger responses are from different hands rather than the same hand is referred to as the response interference effect. The effect has been attributed both to response strategies and motor programming processes. In this study three experiments are reported which examined the contributions of response selection processes to the response interference effect. Response selection processes are viewed as those operations related most directly to the response strategies used with reaction-time tasks. In each experiment, the response selection requirements for the reaction-time tasks were varied to determine the influence on the response interference effect. Results of Experiments 1 and 2 indicated that when response selection requirements were minimized, the response interference effect was eliminated. However, Experiment 3 demonstrated that when response selection was required, even when the probability of a response was high (80%), the response interference effect was evident. The results of the study are consistent with the response preparation hypothesis which posits that the type of preparation strategy adopted by the performer will determine whether response interference is present.