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The default mode network (DMN) is considered a unified core brain function for generating subjective mental experiences, such as mind wandering. We propose a novel cognitive framework for understanding the unity of the DMN from the perspective of hemispheric asymmetry. Using transcranial direct current stimulation (tDCS), effective connectivity estimation, and machine learning, we show that the bilateral angular gyri (AG), which are core regions of the DMN, exhibit heterogeneity in both inherent network organization and mind wandering regulation. Inherent heterogeneities are present between the right and left AG regarding not only effective connectivity, but also mind wandering regulation; the right AG is related to mind-wandering reduction, whereas the left AG is related to mind-wandering generation. Further supporting this observation, we found that only anodal tDCS of the right AG induced machine learning-detectable changes in effective connectivity and regional amplitude, which could possibly be linked to reduced mind wandering. Our findings highlight the importance of hemispheric asymmetry to further understand the function of the DMN and contribute to the emerging neural model of mind wandering, which is necessary to understand the nature of the human mind.

Creativity consists of divergent and convergent thinking, with both related to individual eye blinks at rest. To assess underlying mechanisms between eye blinks and traditional creativity tasks, we investigated the relationship between creativity performance and eye blinks at rest and during tasks. Participants performed an alternative uses and remote association task while eye blinks were recorded. Results showed that the relationship between eye blinks at rest and creativity performance was compatible with those of previous research. Interestingly, we found that the generation of ideas increased as a function of eye blink number during the alternative uses task. On the other hand, during the remote association task, accuracy was independent of eye blink number during the task, but response time increased with it. Moreover, eye blink changes in participants who responded quickly during the remote association task were different depending on their resting state eye blinks; that is, participants with many eye blinks during rest showed little increasing eye blinks and achieved solutions quickly. Positive correlations between eye blinks during creative tasks and yielding ideas on the alternative uses task and response time on the remote association task suggest that eye blinks during creativity tasks relate to divergent thinking processes such as conceptual reorganization.

This study developed and examined the validity of Japanese versions of the Daydream Frequency Scale (DDFS) and the Mind Wandering Questionnaire (MWQ), which measures propensity for spontaneous thoughts and mind wandering, respectively. In Study 1, we translated the items of the DDFS and the MWQ into Japanese and verified their validity. In Study 2, we confirmed the correlation of both scales with mind wandering, as measured by thought sampling during an attention-demanding task. These two studies revealed a dissociation between the properties of the scales; while DDFS reflects propensity for spontaneous thoughts, MWQ specifically reflects propensity for mind,wandering. We discuss the usefulness of the DDFS and the MWQ for studying the psychological functions of spontaneous thoughts and mind wandering.

Prediction of the initial compatibility of heterosexual individuals based on self-reported traits and preferences has not been successful, even with significantly developed information technology. To overcome the limitations of self-reported measures and predict compatibility, we used functional connectivity profiles from resting-state functional magnetic resonance imaging (fMRI) data that carry rich individual-specific information sufficient to predict psychological constructs and activation patterns during social cognitive tasks. Several days after collecting data from resting-state fMRIs, participants undertook a speed-dating experiment in which they had a 3-min speed date with every other opposite-sex participant. Our machine learning algorithm successfully predicted whether pairs in the experiment were compatible or not using (dis)similarity of functional connectivity profiles obtained before the experiment. The similarity and dissimilarity of functional connectivity between individuals and these multivariate relationships contributed to the prediction, hence suggesting the importance of complementarity (observed as dissimilarity) as well as the similarity between an individual and a potential partner during the initial attraction phase. The result indicates that the salience network, limbic areas, and cerebellum are especially important for the feeling of compatibility. This research emphasizes the utility of neural information to predict complex phenomena in a social environment that behavioral measures alone cannot predict.

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Research has shown that focused attention meditation not only improves our cognitive and motivational functioning (e.g., attention, mental health), it influences the way our brain networks [e.g., default mode network (DMN), fronto-parietal network (FPN), and sensory-motor network (SMN)] function and operate. However, surprisingly little attention has been paid to the possibility that meditation alters the architecture (composition) of these functional brain networks. Here, using a single-case experimental design with intensive longitudinal data, we examined the effect of mediation practice on intra-individual changes in the composition of whole-brain networks. The results showed that meditation (1) changed the community size (with a number of regions in the FPN being merged into the DMN after meditation) and (2) led to instability in the community allegiance of the regions in the FPN. These results suggest that, in addition to altering specific functional connectivity, meditation leads to reconfiguration of whole-brain network architecture. The reconfiguration of community architecture in the brain provides fruitful information about the neural mechanisms of meditation.