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Abstract Numerous studies demonstrate that moment-to-moment neural variability is behaviorally relevant and beneficial for tasks and behaviors requiring cognitive flexibility. However, it remains unclear whether the positive effect of neural variability also holds for cognitive persistence. Moreover, different brain variability measures have been used in previous studies, yet comparisons between them are lacking. In the current study, we examined the association between resting-state BOLD signal variability and two metacontrol policies (i.e., persistence vs. flexibility). Brain variability was estimated from resting-state fMRI (rsfMRI) data using two different approaches (i.e., Standard Deviation (SD), and Mean Square Successive Difference (MSSD)) and metacontrol biases were assessed by three metacontrol-sensitive tasks. Results showed that brain variability measured by SD and MSSD was highly positively related. Critically, higher variability measured by MSSD in the attention network, parietal and frontal network, frontal and ACC network, parietal and motor network, and higher variability measured by SD in the parietal and motor network, parietal and frontal network were associated with reduced persistence (or greater flexibility) of metacontrol (i.e., larger Stroop effect or worse RAT performance). These results show that the beneficial effect of brain signal variability on cognitive control depends on the metacontrol states involved. Our study highlights the importance of temporal variability of rsfMRI activity in understanding the neural underpinnings of cognitive control.

Abstract The most widely used measurements of mindfulness are the Mindful Attention Awareness Scale (MAAS) and the Five Facet Mindfulness Questionnaire (FFMQ). However, controversies exist regarding the application of these scales. Additionally, the neural mechanisms of dispositional mindfulness havebecome a topic of interest. In the current study, we used surface-based methodology to identify the brain regions underlying individual differences in dispositional mindfulness in a large non-clinical sampleand compared the two instruments for measuring the dispositional mindfulness. The results indicated that theMAAS scores were significantly associated with increased greymatter volumes in the right precuneus and the significant association between the precuneus and depression symptomatology was mediated by MAAS scores. Regarding the FFMQ, the Describing, Nonjudging, and Nonreactivity facets were selectively associated with the cortical volume, thickness and surface area of multiple prefrontal regions as well as the inferior parietal lobule. Importantly, Describing mediated the association between the dorsolateral PFC volume and the cognitive reappraisal strategies of emotion regulation. These resultssuggested that the MAASwere mainly associated with self-awareness, while the FFMQ facets were selectively involved in emotion regulation, attention control and self-awareness. Therefore, this study characterized the differences in inter-individual variability between the two typical measurements of dispositional mindfulnessand the correlations between those measurements and imaging analyses.