Elevated Blink Rates Predict Mind Wandering: Dopaminergic Insights into Attention and Task Focus.

Background: The study investigated the neural correlates of mind wandering using eyeblink rate (EBR) and variability (EBV) proxies. Dopamine, a neurotransmitter integral to the brain's reward system, has been implicated in regulating both task-unrelated and task-focused thinking. This study sought to clarify the relationships between dopaminergic function and cognitive control during a task by utilizing EBR and EBV as proxy measures.

Methods: Vertical electrooculogram and brain event-related potential (ERP) data were gathered from 24 adult participants while they performed a computerized cognitive task. During the task (3-stimulus visual oddball procedure), participants discriminated between an infrequently seen target stimulus, an infrequent novel stimulus (for evaluating task engagement and distraction), and a commonly occurring nontarget stimulus. A retrospective questionnaire (Dundee Stress State Questionnaire, DSSQ) assessed task-unrelated (TUT) and task-related (TRT) thinking directly after task completion. The P3a ERP brain indexes at the Cz and Fz scalp electrode sites were also considered as a secondary proxy measure of dopamine function.

Results: The main finding revealed that higher EBR was associated with higher TUT, suggesting a link between elevated dopaminergic activity and mind wandering. There was also a marginal negative correlation with P3a latency at the Fz scalp location and TUT, indicative of heightened responsiveness to distraction in general. For TRT, there was a positive correlation with P3a amplitudes at Fz, suggesting a role in task-related engagement and focus on all stimuli during the task. Regarding behavior, EBR and EBV were negatively correlated with Sigma ex-Gaussian task reaction time (RT), suggesting that more stable cognitive states are associated with higher blink rates and variability. Tau RT positively correlated with blink variability and P3a amplitudes at Fz and Cz, indicative of attentional lapse. Regression analyses showed that EBR and Mu RT predicted TUT, while TRT was predicted by P3a amplitude at Fz. More blinks and slower responses were related to TUT, whereas greater focus on the task stimuli (P3a amplitude) was related to TRT.

Conclusions: These data underscore the importance of dopamine during mind wandering and task focus. In addition, this study argues for using ex-Gaussian analysis to understand the complex dynamics of attentional control during mind wandering.