Inhibitory control and mind wandering; more difficult inhibition decreases mind wandering, within limits

Our mind wanders a surprisingly high proportion of the time. This propensity can be modulated by what we are doing however; if we are engrossed in a book, or doing a difficult task, our minds tend to wander less. In the current article, we examine three types of inhibitory control, response withholding, response selection and irrelevant-information suppression, as drivers of probe-caught mind wandering episodes. In Experiment 1, participants performed a Go/No-Go task in which, on some blocks participants would always respond, while in others they would have to withhold their response on a subset of trials. In Experiment 2, participants performed an alternative forced choice task, in some blocks between two responses, and in others, between six responses. In both these experiments, mind wandering tended to decrease when either a response may have to be withheld (Experiment 1), or when more response possibilities were present (Experiment 2). In Experiment 3, participants performed a numerical Stroop task in which to succeed they had to suppress the physical size of a number, and instead respond to the side the larger numerical value was presented on. In this experiment, difficulty was induced by how often the numerical values were close, rather than far, from one another; orthogonal to the inhibitory control component of physical size. In this experiment, we found no effect of difficulty on mind wandering. We situate these findings in the context of the role of inhibitory control and task difficulty as determinants of mind wandering during cognitive tasks.