Cardiac and ocular correlates of mind wandering in meditators and non-meditators during a sustained attention to response task

Abstract

Abstract Mind wandering refers to spontaneous shifts of attention from ongoing tasks to unrelated thoughts. Evidence shows that such shifts are characterized by behavioral and physiological changes, such as heart rate and eye blinks. However, previous findings on cardiac changes during mind wandering are mixed, and little is known about whether mindfulness experience and acceptance-related traits are associated with distinct psychophysiological responses to mind wandering. To shed light on this topic, we investigated psychophysiological correlates of mind wandering in 26 experienced meditators and 24 non-meditating controls during a Sustained Attention to Response Task (SART) with thought probes. We recorded heart rate and eye blinks; mindfulness-related traits and mind wandering phenomenology were assessed through questionnaires. Results showed that, while mind wandering episodes were associated with more frequent eye blinks and slower reaction times in both groups, between-group differences emerged for heart rate. Indeed, only meditators showed a significant heart rate reduction during mind wandering, whereas controls did not. In addition, individual heart rate differences between mind wandering and on-task SART episodes were associated with self-reported levels of experiential acceptance. Overall, meditators reported higher levels of experiential acceptance and assessed their mind wandering episodes as more realistic and concrete than controls. These findings contribute to the literature by showing that, while eye blinks and reaction times may reflect the general attentional cost of mind wandering, heart rate may be more sensitive to individual differences in how these episodes are experienced and regulated, particularly in relation to meditation experience and experiential acceptance.