Mind wandering during creative incubation predicts increases in creative performance in a writing task.

Previous studies suggest that taking breaks from creative problem solving (i.e., incubation periods) enhances subsequent performance, possibly due to mind wandering during these breaks. The present preregistered study investigated whether different types of incubation periods, designed to either promote or suppress mind wandering, influence creativity in a writing task. Participants wrote two fictional short stories based on a prompt, separated by a 10-min incubation task (0-back task, 2-back task, mindfulness meditation, or no-break control). To distinguish story-specific incubation effects from more general cognitive benefits, some participants received the same prompt after the break while others received a new prompt. Mind wandering during incubation was assessed with a validated retrospective questionnaire and story creativity was evaluated by both human raters and a semantic distance-based measure. Results showed no significant differences in creative improvement (pre- to post-incubation) across incubation tasks. However, regardless of task, greater mind wandering during incubation predicted greater within-subject creative improvement, as assessed by semantic distance, for participants who received the same prompt after the break but not for those who received a new prompt. Notably, this benefit was specific to mind wandering and did not extend to other types of thought during incubation, including explicit thought about the story. The relationship remained significant after controlling for dispositional mind wandering and was corroborated by creativity ratings from GPT-4. These findings suggest a potentially beneficial role of mind wandering during the incubation of a creative writing task.