Paradoxical effects of compulsive perseveration: Sentence repetition causes semantic uncertainty

• Earlier studies have shown that OCD-like perseverative behavior ironically induces uncertainty.
• This study examined whether sentence repetitions leads to semantic uncertainty.
• Results showed that sentence repetition induces semantic uncertainty and increases with more sentence repetitions.
• The findings suggest that all forms of perseveration could have negative effects and are potential treatment targets.

Many patients with obsessive compulsive disorder (OCD) perform perseverative checking behavior to reduce uncertainty, but studies have shown that this ironically increases uncertainty. Some patients also tend to perseveratively repeat sentences. The aim of this study was to examine whether sentence repetitions leads to semantic uncertainty and how fast this effect occurs. We also explored if effects of repeating sentences are affected by simultaneously looking at the primary object in the repeated sentence (e.g., looking at a mug while saying “the mug is clean”). Between a pre- and post-test, 165 students repeated short sentences only once (control conditions), or 5, 10 or 20 times (experimental conditions). In the pre- and post-test, they completed a questionnaire about feelings of uncertainty and dissociation. While repeating the sentence, participants looked at the object that was part of their perseveration (relevant) or looked at a white wall (irrelevant). Results showed that sentence repetition induces semantic uncertainty, which increased with more sentence repetitions, and was the largest after 20 repetitions. This effect was not qualified by looking at the object of perseveration. These and earlier findings suggest different types of OC-like perseveration have detrimental effects and may fruitfully be targeted in psychological treatments of OCD.