Obsessive-compulsive tendencies shift the balance between competitive neurocognitive functions.

Obsessive-compulsive disorder (OCD) has been theorized to reflect an imbalance between automatic and goal-directed processes. However, evidence for this imbalance has relied almost exclusively on reward- and feedback-based paradigms, leaving unsupervised learning mechanisms largely unexplored. We investigated this imbalance by examining the relationship between statistical learning (SL) -a feedback-free, implicit mechanism for detecting environmental regularities - and cognitive flexibility, the ability to adapt behavior to changing demands. Adopting a spectrum approach to obsessive-compulsive (OC) tendencies, a total of 404 university students completed an online probabilistic sequence learning task and a card-sorting task. Results revealed an antagonistic relationship between SL and cognitive flexibility, such that stronger SL was associated with lower cognitive flexibility. Crucially, this inverse association weakened with increasing OC tendencies. These findings provide the first evidence that OC tendencies alter the interplay between automatic and goal-directed functions in a purely unsupervised learning context, extending current theoretical frameworks beyond supervised and reward-dependent paradigms.