Research On The Relationship Between Mind Wandering And Attentional Networks

The mind tends to flit, often when there is a lack of demands for concentration, but even when processing a demanding task. This is a ubiquitous phenomenon referred to as mind wandering (MW). Since an observation from cognitive neuroscience of a coordinated brain system now known as the "default mode network", which shows increased activity in the absence of external task, rapid growth has been seen in the study of mind wandering.Like many other cognitive functions, there are individual differences in MW. It has been shown that MW rates are reliable over different tasks and daily life, indicating it is a stable cognitive characteristic. MW was suggested to be viewed as a state of decoupled attention, that attention is divided between external task processing and internal thoughts and feelings when the mind wanders. A wealth of studies have been conducted to support this theory, in an indirect way, however. Few of them directly examined the relationship between MW and attention.As we all know, attention is a complex system, which can be divided into three networks:alerting, orienting and executive control, according to Posner and Petersen. Therefore, in order to explore the mechanism of attentional decoupling, it is necessary to investigate how the attentional components vary in different wandering minds.By utilizing psychophysical methods as well as functional connectivity magnetic resonance imaging, present study tested the relationship between MW and every attentional network. Participants in this study were assigned to high/low-MW group, according to their reports in a Sustained Attention to Response Task. The predicted effects of MW rates on the SART indices and the scores from daydream frequency scale supported the validity of the subjective self-reports. In the first part, attention network test was employed to measure the efficiency of three attentional networks, and the scores were compared between the two groups; in the second part, test for attentional performance, spatial precueing paradigm and a AX version of continuous performance task were used to assess the subcomponents of the three attentional networks, and their performance was compared; in the third part, participants were scanned under resting state, correlation analysis were administered respectively between the functional connectivity within three resting state networks (the dorsal attention system, the ventral attention system and the cingulo-opercular system) and MW rates.The main findings of this study are as follows:(1) No significant differences of tonic/phasic alerting efficiencies were found in different groups.(2) After the external stimuli showing for a span of time, high-MW group could disengage their attention much faster, which was in accordance with the finding of decreased connectivity within the ventral attention network with the increase of MW rates, indicating that attention resources caputered by the task-unrelated external stimuli would fade away sooner. While the two groups could equally orient their attention voluntarily.(3) High-MW group may have a lower ability to maintain task goals, as well as to resolve conflicts intentionally, the former of which could be supported by the decreased connectivity within the cingulo-opercular system. Nevertheless, high-MW group might have a higher ability of automatic inhibitory control, implying a compensation for intentional inhibitory control. (4) MW and distractibility may share some common attention mechanisms while still have some differences.