| dc.description.abstract | Voluntary task switching (VTS) paradigms are often used to assess cognitive flexibility in experimental settings. Here, the cognitive processes related to switching tasks and behavioral changes over time in VTS paradigms are assessed. In Chapter 2, a drift diffusion model was applied to two versions of a VTS paradigm in separate samples; results indicate that more proactive preparation was associated with task switches, and that requiring participants to overtly indicate their task choice affected the timing of task set preparation. In Chapter 3, improvements in reaction time and/or accuracy consistent with practice effects were identified across three different VTS paradigms. In two of the three paradigms, group-level declines in switch rates over time were also present, consistent with hypotheses that supported reduction in cognitive effort throughout the task and compensatory behavioral changes to combat early fatigue effects. Changes in switch rates over time were related to individual differences in approach/avoidance behavior in the third paradigm despite the lack of significant change at a group level. Chapter 4 examined the relationship between changes in switch rates over time and changes in EEG measures over time thought to index cognitive effort expenditure and fatigue. Chapter 4 replicated declines in switch rate over time at a group level identified in Chapter 3. However, the degree of change in switch rate was not related to change in any EEG measure examined, and no support for either proposed mechanism (effort avoidance or fatigue) was found. The series of experiments establishes replicable patterns in voluntary task switching performance related to preparation timing and changes in switch rates that should be explored further in future work. | en |
