Inside a child's mind: The relations between mind wandering and executive function across 8- to 12-year-olds.

Mind wandering refers to attention oriented away from a current task to thoughts unrelated to the task, often resulting in poorer task performance. In adults, mind wandering is a common occurrence that is associated with the executive function facets of inhibitory control, working memory capacity, and task switching. In this study, we cross-sectionally examined whether the relation between mind wandering frequency and executive function changes across 8- to 12-year-old children. A total of 100 children completed three tasks targeting three facets of executive function. During each task, participants were occasionally prompted to report whether they were focused on the task or mind wandering. In examining the association between mind wandering frequency and executive function across the age range, we found a significant interaction between age and working memory capacity, such that it was negatively associated with mind wandering frequency only in 12-year-olds. This interaction with age was not significant for inhibitory control and task switching ability. Our results revealed differential relations between mind wandering and executive function facets, which vary with developmental stages. These findings highlight potential areas for targeted intervention to improve mind wandering regulation in children.

Distinct electrophysiological signatures of task-unrelated and dynamic thoughts.

Humans spend much of their lives engaging with their internal train of thoughts. Traditionally, research focused on whether or not these thoughts are related to ongoing tasks, and has identified reliable and distinct behavioral and neural correlates of task-unrelated and task-related thought. A recent theoretical framework highlighted a different aspect of thinking-how it dynamically moves between topics. However, the neural correlates of such thought dynamics are unknown. The current study aimed to determine the electrophysiological signatures of these dynamics by recording electroencephalogram (EEG) while participants performed an attention task and periodically answered thought-sampling questions about whether their thoughts were 1) task-unrelated, 2) freely moving, 3) deliberately constrained, and 4) automatically constrained. We examined three EEG measures across different time windows as a function of each thought type: stimulus-evoked P3 event-related potentials and non-stimulus-evoked alpha power and variability. Parietal P3 was larger for task-related relative to task-unrelated thoughts, whereas frontal P3 was increased for deliberately constrained compared with unconstrained thoughts. Frontal electrodes showed enhanced alpha power for freely moving thoughts relative to non-freely moving thoughts. Alpha-power variability was increased for task-unrelated, freely moving, and unconstrained thoughts. Our findings indicate distinct electrophysiological patterns associated with task-unrelated and dynamic thoughts, suggesting these neural measures capture the heterogeneity of our ongoing thoughts.

How to Interpret Resting-State fMRI: Ask Your Participants.

Resting-state fMRI (rsfMRI) reveals brain dynamics in a task-unconstrained environment as subjects let their minds wander freely. Consequently, resting subjects navigate a rich space of cognitive and perceptual states (i.e., ongoing experience). How this ongoing experience shapes rsfMRI summary metrics (e.g., functional connectivity) is unknown, yet likely to contribute uniquely to within- and between-subject differences. Here we argue that understanding the role of ongoing experience in rsfMRI requires access to standardized, temporally resolved, scientifically validated first-person descriptions of those experiences. We suggest best practices for obtaining those descriptions via introspective methods appropriately adapted for use in fMRI research. We conclude with a set of guidelines for fusing these two data types to answer pressing questions about the etiology of rsfMRI.

Top-Down Attentional Modulation in Human Frontal Cortex: Differential Engagement during External and Internal Attention.

Decades of electrophysiological research on top-down control converge on the role of the lateral frontal cortex in facilitating attention to behaviorally relevant external inputs. However, the involvement of frontal cortex in the top-down control of attention directed to the external versus internal environment remains poorly understood. To address this, we recorded intracranial electrocorticography while subjects directed their attention externally to tones and responded to infrequent target tones, or internally to their own thoughts while ignoring the tones. Our analyses focused on frontal and temporal cortices. We first computed the target effect, as indexed by the difference in high frequency activity (70-150 Hz) between target and standard tones. Importantly, we then compared the target effect between external and internal attention, reflecting a top-down attentional effect elicited by task demands, in each region of interest. Both frontal and temporal cortices showed target effects during external and internal attention, suggesting this effect is present irrespective of attention states. However, only the frontal cortex showed an enhanced target effect during external relative to internal attention. These findings provide electrophysiological evidence for top-down attentional modulation in the lateral frontal cortex, revealing preferential engagement with external attention.

Daily mindfulness training reduces negative impact of COVID-19 news exposure on affective well-being.

COVID-19 has led to mental health adversities worldwide. The current study examined whether daily practice of brief mindfulness training has a beneficial impact on affective well-being, and mitigates the negative impact of exposure to COVID-19 news during the pandemic. Participants were randomly assigned into a mindfulness training (MT) group or a waitlist control (WC) group. Participants in the MT group practiced guided mindfulness meditation for a minimum of 10 min each day for 10 days. Both groups completed questionnaires assessing well-being at baseline and after the 10-day period. We also included four ecological momentary assessments (EMA) interspersed throughout the day to measure fine-grained affective states and recent exposure to COVID-19-related news, which has been linked to negative affect. We observed an increase in positive affect in the MT group compared to the WC group in the post-training assessment. However, no group differences emerged in the other three post-training affective measures of negative affect, anxiety and depression. EMA revealed that the MT group also showed more positive affective valence than the WC group across the 10 days. Notably, the WC group reported more negative affective valence following COVID-19 news exposure, whereas the MT group was not impacted. Taken together, our study indicates brief sessions of guided mindfulness meditation during COVID-19 may boost positive affect and serve as a protective buffer against the negative impact of exposure to COVID-19-related news on affective well-being. These findings highlight the utility of mindfulness meditation as an accessible and cost-effective technique to elevate positive affect amidst the COVID-19 pandemic.

Study protocol of the Aerobic exercise and CogniTIVe functioning in women with breAsT cancEr (ACTIVATE) trial: a two-arm, two-centre randomized controlled trial.

BACKGROUND: Up to 75% of women diagnosed with breast cancer report chemotherapy-related cognitive changes (CRCC) during treatment, including decreased memory, attention, and processing speed. Though CRCC negatively impacts everyday functioning and reduces overall quality of life in women diagnosed with breast cancer, effective interventions to prevent and/or manage CRCC are elusive. Consequently, women seldom receive advice on how to prevent or manage CRCC. Aerobic exercise is associated with improved cognitive functioning in healthy older adults and adults with cognitive impairments. Accordingly, it holds promise as an intervention to prevent and/or manage CRCC. However, evidence from randomized controlled trials (RCTs) supporting a beneficial effect of aerobic exercise on CRCC is limited. The primary aim of the ACTIVATE trial is to evaluate the impact of supervised aerobic exercise on CRCC in women receiving chemotherapy for breast cancer. METHODS: The ACTIVATE trial is a two-arm, two-centre RCT. Women diagnosed with stage I-III breast cancer and awaiting neo-adjuvant or adjuvant chemotherapy are recruited from hospitals in Ottawa (Ontario) and Vancouver (British Columbia), Canada. Recruits are randomized to the intervention group (aerobic exercise during chemotherapy) or the wait-list control group (usual care during chemotherapy and aerobic exercise post-chemotherapy). The primary outcome is cognitive functioning as measured by a composite cognitive summary score (COGSUM) of several neuropsychological tests. Secondary outcomes are self-reported cognitive functioning, quality of life, and brain structure and functioning (measured by magnetic resonance imaging (MRI)/functional MRI and electroencephalography). Assessments take place pre-chemotherapy (pre-intervention), mid-way through chemotherapy (mid-intervention/mid-wait period), end of chemotherapy (post-intervention/post-wait period; primary endpoint), 16-weeks post-chemotherapy, and at 1-year post-baseline. DISCUSSION: Aerobic exercise is a promising intervention for preventing and/or managing CRCC and enhancing quality of life among women diagnosed with breast cancer. The ACTIVATE trial tests several novel hypotheses, including that aerobic exercise can prevent and/or mitigate CRCC and that this effect is mediated by the timing of intervention delivery (i.e., during versus post-chemotherapy). Findings may support prescribing exercise during (or post-) chemotherapy for breast cancer and elucidate the potential role of aerobic exercise as a management strategy for CRCC in women with early-stage breast cancer. TRIAL REGISTRATION: The trial was registered with the ClinicalTrials.gov database ( NCT03277898 ) on September 11, 2017.

Systematic comparison between a wireless EEG system with dry electrodes and a wired EEG system with wet electrodes.

Recent advances in dry electrodes technology have facilitated the recording of EEG in situations not previously possible, thanks to the relatively swift electrode preparation and avoidance of applying gel to subject's hair. However, to become a true alternative, these systems should be compared to state-of-the-art wet EEG systems commonly used in clinical or research applications. In our study, we conducted a systematic comparison of electrodes application speed, subject comfort, and most critically electrophysiological signal quality between the conventional and wired Biosemi EEG system using wet active electrodes and the compact and wireless F1 EEG system consisting of dry passive electrodes. All subjects (n = 27) participated in two recording sessions on separate days, one with the wet EEG system and one with the dry EEG system, in which the session order was counterbalanced across subjects. In each session, we recorded their EEG during separate rest periods with eyes open and closed followed by two versions of a serial visual presentation target detection task. Each task component allows for a neural measure reflecting different characteristics of the data, including spectral power in canonical low frequency bands, event-related potential components (specifically, the P3b), and single trial classification based on machine learning. The performance across the two systems was similar in most measures, including the P3b amplitude and topography, as well as low frequency (theta, alpha, and beta) spectral power at rest. Both EEG systems performed well above chance in the classification analysis, with a marginal advantage of the wet system over the dry. Critically, all aforementioned electrophysiological metrics showed significant positive correlations (r = 0.54-0.89) between the two EEG systems. This multitude of measures provides a comprehensive comparison that captures different aspects of EEG data, including temporal precision, frequency domain as well as multivariate patterns of activity. Taken together, our results indicate that the dry EEG system used in this experiment can effectively record electrophysiological measures commonly used across the research and clinical contexts with comparable quality to the conventional wet EEG system.

Lateral prefrontal cortex lesion impairs regulation of internally and externally directed attention.

Our capacity to flexibly shift between internally and externally directed attention is crucial for successful performance of activities in our daily lives. Neuroimaging studies have implicated the lateral prefrontal cortex (LPFC) in both internally directed processes, including autobiographical memory retrieval and future planning, and externally directed processes, including cognitive control and selective attention. However, the causal involvement of the LPFC in regulating internally directed attention states is unknown. The current study recorded scalp EEG from patients with LPFC lesions and healthy controls as they performed an attention task that instructed them to direct their attention either to the external environment or their internal milieu. We compared frontocentral midline theta and posterior alpha between externally and internally directed attention states. While healthy controls showed increased theta power during externally directed attention and increased alpha power during internally directed attention, LPFC patients revealed no differences between the two attention states in either electrophysiological measure in the analyzed time windows. These findings provide evidence that damage to the LPFC leads to dysregulation of both types of attention, establishing the important role of LPFC in supporting sustained periods of internally and externally directed attention.

Migraine and attention to visual events during mind wandering.

Although migraine is traditionally categorized as a primary headache disorder, the condition is also associated with abnormalities in visual attentional function in between headache events. Namely, relative to controls, migraineurs show both a heightened sensitivity to nominally unattended visual events, as well as decreased habituation responses at sensory and post-sensory (cognitive) levels. Here we used event-related potentials (ERPs) to examine whether cortical hypersensitivities in migraineurs extend to mind wandering, or periods of time wherein we transiently attenuate the processing of external stimulus inputs as our thoughts drift away from the on-going task at hand. Participants performed a sustained attention to response task while they were occasionally queried as to their attentional state-either "on-task" or "mind wandering." We then analyzed the ERP responses to task-relevant stimuli as a function of whether they immediately preceded an on-task versus mind wandering report. We found that despite the commonly reported heightened visual sensitivities in our migraine group, they nevertheless manifest a reduced cognitive response during periods of mind wandering relative to on-task attentional states, as measured via amplitude changes in the P3 ERP component. This suggests that our capacity to attenuate the processing of external stimulus inputs during mind wandering is not necessarily impaired by the class of cortical hypersensitivities characteristic of the interictal migraine brain.

I don't feel your pain (as much): the desensitizing effect of mind wandering on the perception of others' discomfort.

Mind wandering reduces both the sensory and cognitive processing of affectively neutral stimuli, but whether it also modulates the processing of affectively salient stimuli remains unclear. In particular, we examined whether mind wandering attenuates one's sensitivity to observing mild pain in others. In the first experiment, we recorded event-related potentials (ERPs) as participants viewed images of hands in either painful or neutral situations, while being prompted at random intervals to report whether their thoughts were on task or mind wandering. We found that the brain's later response to painful images was significantly reduced immediately preceding "mind-wandering" versus "on-task" reports, as measured via amplitude decreases in a frontal-central positivity beginning approximately 300 ms poststimulus. In a second, control experiment using behavioral measures, we wanted to confirm whether the subjective sense of pain observed in others does in fact decrease during mind wandering. Accordingly, we asked participants to rate how painful the hand images looked on a 5-point Likert scale, again while taking reports of their mind-wandering states at unpredictable intervals. Consistent with our ERP data, we found that the ratings for painful images were significantly reduced immediately preceding mind-wandering reports. Additional control analyses suggested that the effect could not simply be ascribed to general habituation in the affective response to painful images over time. Collectively, our findings demonstrate that mind wandering can directly modulate the cortical processing of affectively salient stimulus inputs, serving in this case to reduce sensitivity to the physical discomfort of others.

Visual asymmetry revisited: Mind wandering preferentially disrupts processing in the left visual field.

An emerging theory proposes that visual attention operates in parallel at two distinct time scales - a shorter one (<1s) associated with moment-to-moment orienting of selective visuospatial attention, and a longer one (>10s) associated with more global aspects of attention-to-task. Given their parallel nature, here we examined whether these comparatively slower fluctuations in task-related attention show the same visual field asymmetry - namely, a right visual field bias - as often reported for selective visual-spatial attention. Participants performed a target detection task at fixation while event-related potentials (ERP) time-locked to task-irrelevant visual probes presented in the left and right visual fields were recorded. At random intervals, participants were asked to report whether they were "on-task" or "mind wandering". Our results demonstrated that sensory attenuation during periods of "mind wandering" relative to "on-task", as measured by the visual P1 ERP component at electrodes sites contralateral to the stimulus, was only observed for probes presented in the left visual field. In contrast, the magnitude of sensory gain in the right visual field was insensitive to whether participants were "on-task" or "mind wandering". Taken together, our results support the notion that task-related attention at longer time scales and spatial attention at shorter time scales affect the same underlying mechanism in visual cortex.

Differential recruitment of executive resources during mind wandering.

Recent research has shown that mind wandering recruits executive resources away from the external task towards inner thoughts. No studies however have determined whether executive functions are drawn away in a unitary manner during mind wandering episodes, or whether there is variation in specific functions impacted. Accordingly, we examined whether mind wandering differentially modulates three core executive functions-response inhibition, updating of working memory, and mental set shifting. In three experiments, participants performed one of these three executive function tasks and reported their attentional state as either on-task or mind wandering at random intervals. We found that mind wandering led to poorer performance in the response inhibition and working memory tasks, but not the set-shifting task. These findings suggest that mind wandering does not recruit executive functions in a monolithic manner. Rather, it appears to selectively engage certain executive functions, which may reflect the adaptive maintenance of ongoing task performance.

A brief reappraisal intervention leads to durable affective benefits.

People who report frequently using cognitive reappraisal to decrease the impact of potentially upsetting situations report better affective functioning than people who report using cognitive reappraisal less frequently. However, most work linking everyday reappraisal use to affective outcomes has been correlational, making causal inference difficult. In this study, we examined whether 2 weeks of daily practice of reappraising negatively valenced personally relevant events would improve affective functioning compared with a wait-list control. Data were collected between 2021 and 2022 from a sample mainly comprised of females (82%) and who identified as Asian (35%) or White/Caucasian (40%). Our planned analyses indicated that reappraisal decreased depressive symptoms and perceived stress as well as increased life satisfaction both immediately and 4 weeks postintervention. Reductions in depressive symptoms and perceived stress were mediated by increases in reappraisal self-efficacy. These findings support the causal efficacy of brief reappraisal training. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

On the relationship between unprompted thought and affective well-being: A systematic review and meta-analysis.

There is a growing recognition that thoughts often arise independently of external demands. These thoughts can span from reminiscing your last vacation to contemplating career goals to fantasizing about meeting your favorite musician. Often referred to as mind wandering, such frequently occurring unprompted thoughts have widespread impact on our daily functions, with the dominant narrative converging on a negative relationship between unprompted thought and affective well-being. In this systematic review of 76 studies, we implemented a meta-analysis and qualitative review to elucidate if and when unprompted thought is indeed negatively associated with affective well-being in adults. Using a multilevel mixed-model approach on 386 effect sizes from 23,168 participants across 64 studies, our meta-analyses indicated an overall relationship between unprompted thought and worse affective well-being (r¯ = -.18, 95% CI [-.23, -.14]); however, the magnitude and direction of this relationship changed when considering specific aspects of the phenomenon (including thought content and intentionality) and methodological approaches (including questionnaires vs. experience sampling). The qualitative review further contextualizes this relationship by revealing the nuances of how and when unprompted thought is associated with affective well-being. Taken together, our meta-analysis and qualitative review indicate that the commonly reported relationship between unprompted thought and affective well-being is contingent upon the content and conceptualization of unprompted thought, as well as the methodological and analytic approaches implemented. Based on these findings, we propose emerging directions for future empirical and theoretical work that highlight the importance of accounting for when, how, and for whom unprompted thought is associated with affective well-being. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Mind wandering and the adaptive control of attentional resources.

Mind wandering is a natural, transient state wherein our neurocognitive systems become temporarily decoupled from the external sensory environment as our thoughts drift away from the current task at hand. Yet despite the ubiquity of mind wandering in everyday human life, we rarely seem impaired in our ability to adaptively respond to the external environment when mind wandering. This suggests that despite widespread neurocognitive decoupling during mind wandering states, we may nevertheless retain some capacity to attentionally monitor external events. But what specific capacities? In Experiment 1, using traditional performance measures, we found that both volitional and automatic forms of visual-spatial attentional orienting were significantly attenuated when mind wandering. In Experiment 2, however, ERPs revealed that, during mind wandering states, there was a relative preservation of sensitivity to deviant or unexpected sensory events, as measured via the auditory N1 component. Taken together, our findings suggest that, although some selective attentional processes may be subject to down-regulation during mind wandering, we may adaptively compensate for these neurocognitively decoupled states by maintaining automatic deviance-detection functions.

Recent advances in the neuroscience of spontaneous and off-task thought: implications for mental health.

People spend a remarkable 30-50% of awake life thinking about something other than what they are currently doing. These experiences of being "off-task" can be described as spontaneous thought when mental dynamics are relatively flexible. Here we review recent neuroscience developments in this area and consider implications for mental wellbeing and illness. We provide updated overviews of the roles of the default mode network and large-scale network dynamics, and we discuss emerging candidate mechanisms involving hippocampal memory (sharp-wave ripples, replay) and neuromodulatory (noradrenergic and serotonergic) systems. We explore how distinct brain states can be associated with or give rise to adaptive and maladaptive forms of thought linked to distinguishable mental health outcomes. We conclude by outlining new directions in the neuroscience of spontaneous and off-task thought that may clarify mechanisms, lead to personalized biomarkers, and facilitate therapy developments toward the goals of better understanding and improving mental health.

EEG complexity during mind wandering: A multiscale entropy investigation.

Our attention often drifts away from the ongoing task to task-unrelated thoughts, a phenomenon commonly referred to as mind wandering. Ample studies dedicated to delineating its electrophysiological correlates have revealed distinct event-related potentials (ERP) and spectral patterns associated with mind wandering. It remains less clear whether the complexity of the electroencephalography (EEG) changes when our minds wander, a metric that captures the predictability of the time series at varying timescales. Accordingly, this study investigated whether mind wandering impacts EEG signal complexity. We further explored whether such effects differ across timescales, and change in a context-dependent manner as indexed by global and local levels of processing. To address this, we recorded participants' EEG while they completed Navon's global and local processing task and occasionally reported whether they were on-task or mind wandering throughout the task. We found that brain signal complexity as indexed by multiscale entropy decreased at medium timescales in centro-parietal regions and increased at coarse timescales in anterior and posterior regions during mind wandering, as compared to the on-task state, for global processing. Moreover, global processing showed increased complexity at fine to medium timescales compared to local processing. Finally, behavioral performance revealed a context-dependent effect in accuracy measures, with mind wandering showing lower accuracy compared to the on-task state only during the local condition. Taken together, these results indicate that changes in brain signal complexity across timescales may be an important feature of mind wandering.

Intracranial recordings reveal high-frequency activity in the human temporal-parietal cortex supporting non-literal language processing.

Objective: Non-literal expressions such as sarcasm, metaphor and simile refer to words and sentences that convey meanings or intentions that are different and more abstract than literal expressions. Neuroimaging studies have shown activations in a variety of frontal, parietal and temporal brain regions implicated in non-literal language processing. However, neurophysiological correlates of these brain areas underlying non-literal processing remain underexplored. Methods: To address this, we investigated patterns of intracranial EEG activity during non-literal processing by leveraging a unique patient population. Seven neurosurgical patients with invasive electrophysiological monitoring of superficial brain activity were recruited. Intracranial neural responses were recorded over the temporal-parietal junction (TPJ) and its surrounding areas while patients performed a language task. Participants listened to vignettes that ended with non-literal or literal statements and were then asked related questions to which they responded verbally. Results: We found differential neurophysiological activity during the processing of non-literal statements as compared to literal statements, especially in low-Gamma (30-70 Hz) and delta (1-4 Hz) bands. In addition, we found that neural responses related to non-literal processing in the high-gamma band (>70 Hz) were significantly more prominent at TPJ electrodes as compared to non-TPJ (i.e., control) electrodes in most subjects. Moreover, in half of patients, high-gamma activity related to non-literal processing was accompanied by delta-band modulation. Conclusion: These results suggest that both low- and high-frequency electrophysiological activities in the temporal-parietal junction play a crucial role during non-literal language processing in the human brain. The current investigation, utilizing better spatial and temporal resolution of human intracranial electrocorticography, provides a unique opportunity to gain insights into the localized brain dynamics of the TPJ during the processing of non-literal language expressions.

Inspired by distraction: mind wandering facilitates creative incubation.

Although anecdotes that creative thoughts often arise when one is engaged in an unrelated train of thought date back thousands of years, empirical research has not yet investigated this potentially critical source of inspiration. We used an incubation paradigm to assess whether performance on validated creativity problems (the Unusual Uses Task, or UUT) can be facilitated by engaging in either a demanding task or an undemanding task that maximizes mind wandering. Compared with engaging in a demanding task, rest, or no break, engaging in an undemanding task during an incubation period led to substantial improvements in performance on previously encountered problems. Critically, the context that improved performance after the incubation period was associated with higher levels of mind wandering but not with a greater number of explicitly directed thoughts about the UUT. These data suggest that engaging in simple external tasks that allow the mind to wander may facilitate creative problem solving.

Mind-wandering: mechanistic insights from lesion, tDCS, and iEEG.

Cognitive neuroscience has witnessed a surge of interest in investigating the neural correlates of the mind when it drifts away from an ongoing task and the external environment. To that end, functional neuroimaging research has consistently implicated the default mode network (DMN) and frontoparietal control network (FPCN) in mind-wandering. Yet, it remains unknown which subregions within these networks are necessary and how they facilitate mind-wandering. In this review, we synthesize evidence from lesion, transcranial direct current stimulation (tDCS), and intracranial electroencephalogram (iEEG) studies demonstrating the causal relevance of brain regions, and providing insights into the neuronal mechanism underlying mind-wandering. We propose that the integration of complementary approaches is the optimal strategy to establish a comprehensive understanding of the neural basis of mind-wandering.