Exploring the repetition bias in voluntary task switching.

In the voluntary task-switching paradigm, participants are required to randomly select tasks. We reasoned that the consistent finding of a repetition bias (i.e., participants repeat tasks more often than expected by chance) reflects reasonable adaptive task selection behavior to balance the goal of random task selection with the goals to minimize the time and effort for task performance. We conducted two experiments in which participants were provided with variable amount of preview for the non-chosen task stimuli (i.e., potential switch stimuli). We assumed that switch stimuli would initiate some pre-processing resulting in improved performance in switch trials. Results showed that reduced switch costs due to extra-preview in advance of each trial were accompanied by more task switches. This finding is in line with the characteristics of rational adaptive behavior. However, participants were not biased to switch tasks more often than chance despite large switch benefits. We suggest that participants might avoid effortful additional control processes that modulate the effects of preview on task performance and task choice.

Long-Term Follow-up of Cognitive-Behavioral Therapy for Obsessive-Compulsive Disorder: Symptom Severity and the Role of Exposure 8-10 Years After Inpatient Treatment.

Obsessive-compulsive disorder (OCD) can be effectively treated by cognitive behavioral therapy (CBT) with exposure and response prevention (ERP). Yet, little is known about the long-term effects of inpatient CBT up to one decade after treatment. Thirty patients who had been treated with 12 weeks of intensive inpatient CBT with ERP were examined 8-10 years after their stay in hospital with regard to obsessive-compulsive symptoms, secondary outcomes, and use of healthcare services. Significant (p < .001) improvements in OC symptoms with medium and large effects compared to baseline on the Yale-Brown-Obsessive-Compulsive Scale (Y-BOCS) and on the Obsessive-Compulsive Inventory (OCI-R) could still be observed, with 20% of the patients reaching remission status. Continuation of exposure exercises after the inpatient stay was the sole significant factor for improved scores at follow-up. The results suggest that OCD does not necessarily take a chronic course. However, maintenance of exposure training seems to be crucial for sustained improvement.