Task switching and response processes

When switching between tasks, participants are sometimes required to use different response sets for each task: So, task switch and response set switch are commonly confounded. Eleven experiments divided into three series examined transitions of response within a linear four-finger arrangement. The first series examined cued grouping by hand or finger equivalence in both single task and task switching designs. The second considered the effect upon transitions of response when full repetition of the stimulus was included in the design. Results showed that part of the task switch cost is associated with switching between response sets, particularly those of hand. Furthermore, when task switching and repetition trials are mixed, a bias towards switching the response and/or hand is found in task repetition trials when an element of the stimuli is altered. In this instance, response repetition is hindered when a task switch is expected, even for those trials when a switch of task does not occur. Full object repetition facilitates responding, but appears to be a special case whereby repetition of the stimulus facilitates the response previously used. However, the preferences for stimuli presentation are altered according to the type of response subset that is mapped to each task, indicating that response processes have a role in determining the operation of those related to perception. The final series mapped two stimuli to each response: The stimulus-response codes appeared to be weakened, with an increased number of response options exacerbating the influence of the double mapping. The results demonstrate executive processes involved in task set configuration closely depend upon both the assessment of the percept and the motoric processing of the response set and that the grouping of effectors influences the response preferences that are observed. The results are also important for current theories of task set control.