Mind-wandering as spontaneous thought: a dynamic framework

The cognitive and neural bases of creative thought: A cross-domain systematic review and meta-analysis of transcranial direct current stimulation studies

Creative thought enables humans to flexibly generate, evaluate and select novel and adaptive ideas across different contexts. Decades of research indicates that it involves two key aspects: retrieval of previously acquired knowledge and manipulation of that knowledge. However, the cognitive processes underpinning these aspects remain underspecified. The broader clinical-cognitive neuroscience literature suggests these functions rely on general-purpose cognitive mechanisms supporting semantic cognition, controlled episodic memory retrieval, and executive mechanisms. Transcranial direct current stimulation (tDCS) is a neuromodulation technique widely used in creativity and cognitive neuroscience research to examine causal brain-behaviour relationships. To identify converging evidence toward a unifying neurocognitive account of creative thought, we reviewed and meta-analysed 145 sham-controlled tDCS studies (involving 8399 healthy participants aged 18-40), drawn from electronic databases and previous reviews, across creativity and relevant cognitive neuroscience literatures. The results revealed that, only left lateral frontal anodal tDCS promotes creativity (p < .01). In parallel, anodal tDCS over the same region also promotes improvement in many other cognitive processes, including more efficient processing of semantic knowledge (p < .05), more accurate episodic memory retrieval (p < .05), better and more efficient manipulation of buffered knowledge (all p < .001), better self-initiated response generation (i.e., energization; p < .05), and more efficient response selection amongst competing options (i.e., task-setting; p < .01). By merging these previously separate literatures, tDCS studies - although heavily biased toward frontal montages - support the notion that creative thought arises from general-purpose cognitive mechanisms including controlled retrieval and temporary storage of semantic and episodic information, as well as executive mechanisms.

Does Stimulant Medication Status Moderate the Association Between Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms and Rumination?

Previous research suggests that college students with attention-deficit/hyperactivity disorder (ADHD) symptoms are at risk for experiencing ruminative thinking. Although research has shown that stimulant medications reduce ADHD symptoms, no research has looked at whether stimulant medication moderates the association between ADHD symptoms and rumination. Given this gap in the literature, the current study examined whether stimulant medication status moderates the association between ADHD symptoms and rumination. Participants (N = 4,751) were undergraduate psychology students from six universities (70.0% female; Mage = 19.08; SDage = 1.36) who participated in a larger study. College students completed questionnaires related to ADHD symptoms and rumination and indicated whether they were currently taking a stimulant medication. Results of the moderation model indicated a significant main effect for ADHD inattentive symptoms (β = 5.20, p < .05, 95% CI [4.43, 5.98]) and a significant interaction effect between ADHD inattentive symptoms and stimulant medication in relation to rumination (β = -2.41, p < .05, 95% CI [-4.51, -.30]). Examination of conditional effects revealed significant simple slopes for students both on and off medication but a stronger association for those off (β = 5.20, p < .05, 95% CI [4.43, 5.98]) versus on (β = 2.80, p < .05, 95% CI [.78, 4.81]) stimulant medication. Stimulant medication status did not moderate the association between ADHD hyperactive/impulsive symptoms and rumination. Future research should continue to explore the potential benefits of stimulant medication for reducing the association between ADHD inattention symptoms and rumination.

From pre-stimulus activity to the contents of consciousness - A spatiotemporal view: Reply to comments on "Beyond task response-Pre-stimulus activity modulates contents of consciousness"

What are the exact neuronal mechanisms of pre-post-stimulus interaction and how can that account for the intrinsically subjective nature of the contents of consciousness? This is the key question lurking behind the various excellent and very thoughtful commentaries to our target article which we group along four main topics and questions. (i) What is the role of neural features like alpha power, phase dynamics, trial-to-trial variability and fractal scale-free dynamics in yielding pre-post-stimulus interaction and its conscious contents. (ii) What do we mean by 'content' of consciousness? This concerns its meaning, its characterization as internal or external, and its relation to the basic subjectivity of consciousness. (iii) How does our approach stand to other theories of consciousness like the Dendritic Integration Theory (DIT), GNWT and IIT? This concerns the convergence among the different theories that highlight distinct aspects. (iv) How can we detail the spatiotemporal shaping of the contents of consciousness including their intrinsically subjective nature through pre-post-stimulus interaction? This concerns the details of how the non-additive pre-post-stimulus interaction shapes the subjective nature of our experience of conscious contents, that is, how the neuronal activity connects to the phenomenal features of consciousness. Together, we conclude that the contents of consciousness are shaped primarily in a temporal-dynamic and spatial-topographic way through the non-additive pre-post-stimulus interaction. Such spatiotemporal shaping of the contents in our consciousness constitutes their intrinsically subjective nature which must be distinguished from their (more objective) modulation by cognitive, sensory, affective, and motor functions.

Multilevel brain functional connectivity and task-based representations explaining heterogeneity in major depressive disorder

Major depressive disorder (MDD) is a devastating mental disorder characterized by considerable clinical and biological heterogeneity. While comparable clinical symptoms may represent a common pathological endpoint, it is conceivable that distinct neurophysiological mechanisms underlie their manifestation. In this study, both static and model-based dynamic functional connectivity were employed as predictive variables in the normative model to map multilevel functional developmental trajectories and determined clusters of distinguishable MDD subgroups in a large multi-site resting fMRI dataset of 2428 participants (healthy controls: N = 1128; MDD: N = 1300). An independent cohort of 72 participants (healthy controls: N = 35; MDD: N = 37) with both resting fMRI and task-based fMRI data was utilized to validate the identified MDD subtypes and explore subtype-specific task-based neural representations. Our findings indicated brain-wide, interpatient heterogeneous multilevel brain functional deviations in MDD. We identified two distinct and reproducible MDD subtypes, exhibiting comparable severity of clinical symptoms but opposing patterns of multilevel functional deviations. Specifically, MDD subtype 1 displayed positive deviations in the frontoparietal and default mode networks, coupled with negative deviations in the occipital and sensorimotor networks. Conversely, MDD subtype 2 exhibited a significantly contrasting deviation pattern. Additionally, we found that these two identified MDD subtypes exhibited different neural representations during empathic processing, while the subtypes did not differ during implicit face processing. These findings underscore the neurobiological complexity of MDD and highlights the need for a multifaceted approach to diagnosis and treatment that can be tailored specifically to individual subtypes, facilitating personalized and more effective interventions for individuals with MDD.

The 'Task' of Mind-Wandering Splits Both Multiple Demand and Default Mode Regions and Ramps-up the Deactivating Regions

The activation of multiple demand (MD) regions to diverse tasks has been linked to the demands of making task-related cognitive control changes - keeping it focussed on task, controlling attention and working memory, organizing and maintaining a task model that will control the sequence and identity of what is to be done when, etc. Demanding tasks that require such control are also accompanied by a deliberative cognition whereby cognitive changes do not occur automatically and have to be made deliberately. We investigated whether the deliberativeness of cognition activates MD regions regardless of task-related demands. When not engaged in demanding tasks, the mind wanders. We asked participants to do the same during task periods, and to differentiate from rests, we asked them to deliberately and intensely wander their minds across random thoughts. We found that a set of MD regions - pre-supplementary motor area (preSMA), anterior insula, and posterior part of the middle frontal gyrus - activated during these periods, and another set - intraparietal sulcus, right anterior prefrontal cortex - deactivated. In fact, some of the activating regions (e.g., preSMA) activated more during this task than in response to robust working memory updating demands. Dissociations were also present in the Default Mode Network (DMN). Parts of the temporoparietal junction deactivated while posterior cingulate and medial prefrontal regions activated. Lastly, we found that the deactivating regions ramped-up their activity across the 'task' duration, showing that this ramp-up, previously linked to demands of sequentially organizing extended tasks, occurs during any construed task, including those without such demands.

Where creativity meets aesthetics: The Mirror Model of Art revisited with fMRI

How meaning is conveyed from creator to observer is debated in the psychology of art. The Mirror Model of Art represents a theoretical framework for bridging the psychological processes that underpin creative production and aesthetic appreciation of art. Specifically, it postulates that creating art and having an aesthetic experience are "mirrored" processes such that the early stage of aesthetic appreciation corresponds to the late stage of creative production, and conversely, that the late stage of aesthetic appreciation corresponds to the early stage of creative production. We conducted a meta-analysis of fMRI studies in the visual domain to test this hypothesis. Our results reveal that creative production engages the prefrontal cortex, which we attribute to its role in idea generation, whereas aesthetic appreciation engages the visual cortex, anterior insula, parahippocampal gyrus, the fusiform gyrus, and the frontal lobes, regions involved primarily in sensory, perceptual, reward and mnemonic processing. Their direct comparison revealed that creative production was associated with greater activation in the prefrontal cortex, whereas aesthetic appreciation was associated with greater activation in the visual cortex. This meta-analysis largely supports predictions derived from the Mirror Model of Art, by providing a snapshot of neural activity in the relatively early stages in art creators' and observers' minds. Future studies that capture brain function across longer spans of time are needed to understand the expression of creativity and aesthetic appreciation in different stages of information processing in relation to the Mirror Model of Art.

Functional Brain Networks Underlying Autobiographical Event Simulation: An Update

fMRI studies typically explore changes in the BOLD signal underlying discrete cognitive processes that occur over milliseconds to a few seconds. However, autobiographical cognition is a protracted process and requires fMRI tasks with longer trials to capture the temporal dynamics of the underlying brain networks. In the current study, we provided an updated analysis of the fMRI data obtained from a published autobiographical event simulation study, with a slow event-related design (34-sec trials), that involved participants recalling past, imagining past, and imagining future autobiographical events, as well as completing a semantic association control task. Our updated analysis using Constrained Principal Component Analysis for fMRI retrieved two networks reported in the original study: (1) the Default Mode Network, which activated during the autobiographical event simulation conditions but deactivated during the control condition, and (2) the Multiple Demand Network, which activated early in all conditions during the construction of the required representations (i.e., autobiographical events or semantic associates). Two novel networks also emerged: (1) the Response Network, which activated during the scale-rating phase, and (2) the Maintaining Internal Attention Network, which, while active in all conditions during the elaboration of details associated with the simulated events, was more strongly engaged during the imagination and semantic association control conditions. Our findings suggest that the Default Mode Network does not support autobiographical simulation alone, but it co-activates with the Multiple Demand Network and Maintaining Internal Attention Network, with the timing of activations depending on evolving task demands during the simulation process.

Bridging the gap of brain and experience - Converging Neurophenomenology with Spatiotemporal Neuroscience

Neuroscience faces the challenge of connecting brain and mind, with the mind manifesting in first-person experience while the brain's neural activity can only be investigated in third-person perspective. To connect neural and mental states, Neurophenomenology provides a methodological toolkit for systematically linking first-person subjective experience with third-person objective observations of the brain's neural activity. However, beyond providing a systematic methodological strategy ('disciplined circularity'), it leaves open how neural activity and subjective experience are related among themselves, independent of our methodological strategy. The recently introduced Spatiotemporal Neuroscience suggests that neural activity and subjective experience share a commonly underlying feature as their "common currency", notably analogous spatiotemporal dynamics. Can Spatiotemporal Neuroscience inform Neurophenomenology to allow for a deeper and more substantiative connection of first-person experience and third-person neural activity? The goal of our paper is to show how Spatiotemporal Neuroscience and Neurophenomenology can be converged and integrated with each other to gain better understanding of the brain-mind connection. We describe their convergence on theoretical grounds which, subsequently, is illustrated by empirical examples like self, meditation, and depression. In conclusion, we propose that the integration of Neurophenomenology and Spatiotemporal Neuroscience can provide complementary insights, enrich both fields, allows for deeper understanding of brain-mind connection, and opens the door for developing novel methodological approaches in their empirical investigation.

Exploring the link between sleep and cognitive disengagement syndrome (CDS) in young adults: Integrating the role of ADHD

OBJECTIVE

This study aimed to: (1) compare sleep quality and sleep-related parameters in a Turkish adult population with and without CDS and ADHD symptoms; and (2) re-examine the relationship between CDS and sleep by exploring potential associations between sleep problems and CDS symptoms, while also examining the separate roles of sluggishness and daydreaming, as well as possible gender differences.

METHOD

The study included 274 participants (age:18-35, 70.4 % female). The Adult CDS Ratings Scale, the Adult ADHD Self-Report Scale (ASRS), and the Pittsburgh Sleep Quality Index were used. The data were analyzed using SPSS 22 and AMOS 23. Statistical analyses included ANOVA with post-hoc Tamhane's test, Mann-Whitney U test, Spearman Correlation Analysis, and structural equation modeling with path analysis. Linear regression analysis was conducted to identify factors influencing daydreaming.

RESULTS

The study yielded four key findings: CONCLUSIONS: This study is among the first to explore the relationship between CDS symptoms and sleep problems in young adults, accounting for ADHD. Our findings highlight the significant association of hyperactivity/impulsivity and daydreaming with sleep quality, as well as the relationship between poor sleep quality and increased daydreaming and sluggishness, though to a lesser extent than ADHD symptoms. Notably, gender differences emerged, with poor sleep quality affecting CDS symptoms primarily in women, while sluggishness decreased with age in men. These results underscore the importance of considering sleep issues in the context of CDS and ADHD, particularly with attention to gender-specific patterns.

On the neural substrates of mind wandering and dynamic thought: A drug and brain stimulation study

The impact of mind wandering on our daily lives ranges from diminishing productivity, to facilitating creativity and problem solving. There is evidence that distinct internal thought types can be modulated by transcranial direct current stimulation (tDCS), although little is known about optimal stimulation parameters or the mechanisms behind such effects. In addition, recent findings suggest changes in dopamine availability may alter the effect tDCS has on neural and behavioural outcomes. Dopaminergic functioning has also been implicated in executive processes anticorrelated with mind wandering such as attention and working memory, however the neurochemical mechanisms involved in internal thoughts are largely unknown. Here, we investigated the role of dopamine, and tDCS, on internal thought processes. Specifically, using an attentional control task, we tested whether dopamine availability (levodopa or placebo) mediated the effects of online high definition tDCS (HD-tDCS; 2 mA, or sham). There was no evidence for our hypothesised effect of left prefrontal cortex HD-tDCS reducing task unrelated thought, nor freely moving thought. This failure to replicate previous HD-tDCS findings emphasises the importance of employing robust methodological practices within this field to improve confidence in the findings. However, we did find that levodopa reduced freely moving thought, relative to placebo. We also found preliminary evidence that dopamine availability may moderate the relationship between stimulation and behavioural variability performance during periods of task unrelated thought. Overall, these findings suggest that stimulation does not affect dynamic internal thought, however there is initial evidence for the potential effectiveness of targeting the dopaminergic system to reduce spontaneous internal thoughts and improve behavioural performance.

Impact of motor error processing on performance on a working memory task: effect of modulating cognitive load in high and low span groups

Making a motor error, hitting the wrong key for example in responding to a stimulus, impacts perceptual, motor, and cognitive processes by implying a variation in performance and response time on the next trial (Post Error Slowing, Dutilh et al., 2012; Wessel, 2018). Wessel et al. (2022) showed that an error produced on a flanker-type task had a negative impact on a working memory span recognition. This effect is called ERIAM (Error Related Impairment of Active Working Memory) and consists of degradation of memory span following the production of an error on a conflict task concurrent to a memory task. In their study, the ERIAM effect is more pronounced in Low Span individuals. This suggests that these individuals have less stable Working Memory representations and are more likely to be impacted by an error. The presented study replicates the ERIAM protocol of Wessel et al. (2022) by adding variation of cognitive load. In addition, span recognition task is modified with a recall task. Results show a replication of ERIAM effect in our sample. Moreover, ERIAM effect is only significant in lowspan group in the moderate cognitive load condition and in highspan group in the increased load condition. In line with Lavie's load theory (Lavie et al., 2004), we explain these results by the fact that High and Low Span groups do not process cognitive load increase in the same way.

Investigating the Shared and Divergent Neuroanatomical Features of Attentional Deficits in Adolescents

OBJECTIVE

Cognitive disengagement syndrome (CDS), formerly known as sluggish cognitive tempo, is characterized by hypo-activity or slowed behavior, mental fogginess or confusion, excessive sleepiness, and daydreaming. CDS and the predominantly inattentive (IN) presentation of attention-deficit/hyperactivity disorder (ADHD) are frequently co-occurring though separable constructs, each associated with unique constellations of functional impairments. The current study aims to identify their shared and divergent neurobiological correlates.

METHOD

One hundred eighty-one adolescents (Mage=13.9, SDage=2.2) were recruited from the Colorado Learning Disabilities Research Center twin study. Relationships between attentional symptom dimensions - CDS and IN - and brain volume were examined, controlling for age, sex, and average cortical volume. Procedures were repeated in an outside sample of 292 adolescents (Mage=16.8, SDage=1.4) using a 2-item measure of CDS.

RESULTS

Higher levels of CDS symptoms were associated with reduced volume within left ventral parietal, temporo-parietal and temporal regions, regions which fall within the ventral attention network. CDS and IN symptoms were significantly associated with gray matter volume in portions of the dorsal attention and default mode networks in opposite directions. Higher levels of CDS symptoms were associated with reduced volume in the left superior and inferior parietal lobules and left frontal portions of the default mode network, whereas IN symptoms were positively correlated with volume in these areas. Several findings were consistent in the outside sample.

CONCLUSION

Results from the current study provide novel insights into the neurobiological basis of CDS. They suggest that both CDS and IN symptoms are associated with alterations in brain systems that exert top-down attentional control, though likely for differing reasons. The current study enhances understanding of adolescent attentional deficits.

Brain mechanisms underlying the inhibitory control of thought

Controlling action and thought requires the capacity to stop mental processes. Over the past two decades, evidence has grown that a domain-general inhibitory control mechanism supported by the right lateral prefrontal cortex achieves these functions. However, current views of the neural mechanisms of inhibitory control derive largely from research into the stopping of action. Whereas action stopping is a convenient empirical model, it does not invoke thought inhibition and cannot be used to identify the unique features of this process. Here, we review research that addresses how organisms stop a key process that drives thoughts: memory retrieval. This work has shown that retrieval stopping shares right dorsolateral and ventrolateral prefrontal mechanisms with action stopping, consistent with a domain-general inhibitory control mechanism, but also recruits a distinct fronto-temporal pathway that determines the success of mental control. As part of this pathway, GABAergic inhibition within the hippocampus influences the efficacy of prefrontal control over thought. These unique elements of mental control suggest that hippocampal disinhibition is a transdiagnostic factor underlying intrusive thinking, linking the fronto-temporal control pathway to preclinical models of psychiatric disorders and fear extinction. We suggest that retrieval-stopping deficits may underlie the intrusive thinking that is common across many psychiatric disorders.

Linking visual-frontoparietal network neural dynamics to spontaneous cognitive processing

Previous studies in neuroscience have predominantly focused on the role of the default mode network (DMN) in spontaneous thought, with the contributions of other brain regions remaining largely unexplored. In this study, we hypothesized that the visual-frontoparietal network (VFPN) would exhibit distinct macroscopic patterns associated with spontaneous cognitive processing. To test this hypothesis, we analyzed four functional magnetic resonance imaging (fMRI) datasets. Our results revealed that self-reported cognitive states during rest were strongly correlated with specific macroscopic patterns in the VFPN. These patterns were also observed during movie viewing/listening and had previously been identified in multistable perception tasks. Further analysis showed that the microscopic activation patterns in the visual areas were closely linked to self-reported cognitive states. Additionally, we found that memory replay in the visual areas was more pronounced when the frontoparietal network was active, compared to when it was inactive. Finally, fluctuations in the VFPN and their coupling with the hippocampus were significant predictors of offline memory enhancement. In conclusion, these findings demonstrate consistent patterns in the visual and frontoparietal brain regions during resting states that are closely associated with cognitive activity, providing strong evidence for the significant roles of regions beyond the DMN in spontaneous thought.

Hypnagogia, psychedelics, and sensory deprivation: the mythic structure of dream-like experiences

Introduction

Dream-like and psychedelic experiences often display internally illogical structures. Recent theories propose that these experiences function as "spontaneous offline simulations" related to specific brain processes. This study investigates whether such perceived illogicality reflects a distinct, premodern mode of cognition-commonly referred to as "mythic" cognition-rather than a cognitive deficit.

Methods

Thirty-one participants underwent four 90-minute flotation REST (Restricted Environmental Stimulation Technique) sessions designed to induce altered, dream-like states. After each session, participants completed the Phenomenology of Consciousness Inventory (PCI) and additional questions targeting features associated with mythic cognition.

Results

Participants showed significant phenomenological shifts toward experiences characteristic of mythic cognition. Specifically, their altered states during flotation exhibited ontological parallels with mythic conceptions of space, time, and substance.

Discussion

The findings support the hypothesis that the perceived illogicality in altered states arises from a distinct cognitive framework rather than from deficits.

General anaesthesia decreases the uniqueness of brain functional connectivity across individuals and species

The human brain is characterized by idiosyncratic patterns of spontaneous thought, rendering each brain uniquely identifiable from its neural activity. However, deep general anaesthesia suppresses subjective experience. Does it also suppress what makes each brain unique? Here we used functional MRI scans acquired under the effects of the general anaesthetics sevoflurane and propofol to determine whether anaesthetic-induced unconsciousness diminishes the uniqueness of the human brain, both with respect to the brains of other individuals and the brains of another species. Using functional connectivity, we report that under anaesthesia individual brains become less self-similar and less distinguishable from each other. Loss of distinctiveness is highly organized: it co-localizes with the archetypal sensory-association axis, correlating with genetic and morphometric markers of phylogenetic differences between humans and other primates. This effect is more evident at greater anaesthetic depths, reproducible across sevoflurane and propofol and reversed upon recovery. Providing convergent evidence, we show that anaesthesia shifts the functional connectivity of the human brain closer to the functional connectivity of the macaque brain in a low-dimensional space. Finally, anaesthesia diminishes the match between spontaneous brain activity and cognitive brain patterns aggregated from the Neurosynth meta-analytic engine. Collectively, the present results reveal that anaesthetized human brains are not only less distinguishable from each other, but also less distinguishable from the brains of other primates, with specifically human-expanded regions being the most affected by anaesthesia.

Where Is My Mind? The Daydreaming Characteristics Questionnaire, a New Tool to Differentiate Absorptive Daydreaming From Mind-Wandering

OBJECTIVE

Maladaptive daydreaming (MD) is an impairing condition characterized by addiction to narrative, emotional fantasizing, involving dissociative absorption. By compulsively withdrawing toward vivid imaginative scenarios, MD hinders attentional functioning and replaces social interactions. Previous Interview-based research showed clinical importance in differentiating MD from ADHD and the associated construct of mind-wandering. We aimed to create a self-report tool asking directly about the content and structure of distracting thoughts.

METHOD

Two samples, namely, 346 undergraduate students and 381 adults from the general community, completed a novel measure, the Daydreaming Characteristics Questionnaire (DCQ), along with validated measures for ADHD, mind-wandering, MD, dissociation, and general distress.

RESULTS

Exploratory Factor Analyses on the DCQ, replicated across both samples, yielded two distinct factors (immersive daydreaming and daydream functionality) uniquely associated with MD.

CONCLUSION

The DCQ represents characteristics of immersive daydreaming much more than general attentional deficiency and is thus useful in differentiating MD from ADHD/mind-wandering distractions.

Thoughtseeds: A Hierarchical and Agentic Framework for Investigating Thought Dynamics in Meditative States

The Thoughtseeds Framework introduces a novel computational approach to modeling thought dynamics in meditative states, conceptualizing thoughtseeds as dynamic attentional agents that integrate information. This hierarchical model, structured as nested Markov blankets, comprises three interconnected levels: (i) knowledge domains as information repositories, (ii) the Thoughtseed Network where thoughtseeds compete, and (iii) meta-cognition regulating awareness. It simulates focused-attention Vipassana meditation via rule-based training informed by empirical neuroscience research on attentional stability and neural dynamics. Four states-breath_control, mind_wandering, meta_awareness, and redirect_breath-emerge organically from thoughtseed interactions, demonstrating self-organizing dynamics. Results indicate that experts sustain control dominance to reinforce focused attention, while novices exhibit frequent, prolonged mind_wandering episodes, reflecting beginner instability. Integrating Global Workspace Theory and the Intrinsic Ignition Framework, the model elucidates how thoughtseeds shape a unitary meditative experience through meta-awareness, balancing epistemic and pragmatic affordances via active inference. Synthesizing computational modeling with phenomenological insights, it provides an embodied perspective on cognitive state emergence and transitions, offering testable predictions about meditation skill development. The framework yields insights into attention regulation, meta-cognitive awareness, and meditation state emergence, establishing a versatile foundation for future research into diverse meditation practices (e.g., Open Monitoring, Non-Dual Awareness), cognitive development across the lifespan, and clinical applications in mindfulness-based interventions for attention disorders, advancing our understanding of the nature of mind and thought.

Clinically relevant aspects of thought across psychological disorders

Thought-related features are prevalent within psychopathologies, with around 50% of psychiatric disorders including aspects of thought in their diagnostic criteria. Even among higher levels of transdiagnostic work and a stronger focus on thought-related phenomenon, a gap remains between cognitive and clinical fields. Here, we aimed to bridge the gap between these two fields by providing a high-level organization of the most prevalently studied mental health-related aspects of thought. In this review, we surveyed the thought literature with a focus on clinical disorders with thought-related phenomena in their diagnostic criteria. From our review we identified three high level dimensions of thoughts: the content of thought, the dynamics of thought, and the relationship to thought. Within each of these levels, we then expanded on the specific aspects of thought highlighted in the cognitive and clinical literature. Identification of these categorical themes will help to isolate the specific aspects of thought driving the persistence of mental health disorders. Knowledge of the underlying cognitive mechanisms that drive disorder-related impairment can then be used to create more effective and targeted interventions.

Oscillations of the Wandering Mind: Neural Evidence for Distinct Exploration/Exploitation Strategies in Younger and Older Adults

This study traced the neurophysiological signals of fluctuating attention and task-related processing to ascertain the mechanistic basis of transient strategic shifts between competing task focus and mind-wandering, as expressed by the 'exploitation/exploration' framework, and explored how they are differentially affected with age. Thirty-four younger (16 female, mean age 22 years) and 34 healthy older (20 female, mean age 71 years) adults performed the Gradual Contrast Change Detection task; monitoring a continuously presented flickering annulus for intermittent gradual contrast reductions and responding to experience sampling probes to discriminate the nature of their thoughts at discrete moments. Electroencephalography and pupillometry were concurrently recorded during target- and probe-related intervals. Older adults tracked the downward stimulus trajectory with greater sensory integrity (reduced target SSVEP amplitude) and demonstrated earlier initiation of evidence accumulation (earlier onset CPP), attenuated variability in the attentional signal (posterior alpha) and more robust phasic pupillary responses to the target, suggesting steadier attentional engagement with age. Younger adults only exhibited intermittent sensory encoding, indexed by greater variability in the sensory (SSVEP) and attentional (alpha) signals before mind-wandering relative to focused states. Attentional variability was accompanied by disrupted behavioural performance and reduced task-related neural processing, independent of age group. Together, this elucidates distinct performance strategies employed by both groups. Older adults suspended mind-wandering and implemented an exploitative oscillation strategy to circumvent their reduced cognitive resources and allay potential behavioural costs. Conversely, younger adults exhibited greater exploration through mind-wandering, utilising their greater cognitive resources to flexibly alternate between competing goal-directed and mind-wandering strategies, with limited costs.

Neural sensitivity to the heartbeat is modulated by spontaneous fluctuations in subjective arousal during wakeful rest

Spontaneous thoughts, occupying much of one's awake time in daily time, are often colored by emotional qualities. While spontaneous thoughts have been associated with various neural correlates, the relationship between subjective qualities of ongoing experiences and the brain's sensitivity to bodily signals (i.e., interoception) remains largely unexplored. Given the well-established role of interoception in emotion, clarifying this relationship may elucidate how processes relevant to mental health, such as arousal and anxiety, are regulated. We used EEG and ECG to measure the heartbeat evoked potential (HEP), an index of interoceptive processing, while 51 adult participants (34 male, 20 female) visually fixated on a cross image and let their minds wander freely. At pseudo-random intervals, participants reported their momentary level of arousal. This measure of subjective arousal was highly variable within and between individuals but was statistically unrelated to several markers of physiological arousal, including heart rate, heart rate variability, time on task, and EEG alpha power at posterior electrodes. A cluster-based permutation analysis revealed that the HEP amplitude was increased during low relative to high subjective arousal in a set of frontal electrodes during the 0.328 s - 0.364 s window after heartbeat onset. This HEP effect was more pronounced in individuals who reported high, relative to low, levels of state anxiety. Together, our results offer novel evidence that at varying levels of state anxiety, the brain differentially modulates sensitivity to bodily signals in coordination with the momentary, spontaneous experience of subjective arousal-a mechanism that may operate independently of physiological arousal.

Significance Statement

Our findings highlight the relationships between spontaneous fluctuations in subjective arousal, brain-body interactions, and anxiety, offering new insights into how interoception fluctuates with changes in internal states. By showing that interoceptive processing is heightened during lower subjective arousal and that this effect is amplified in individuals with higher state anxiety, our study suggests the brain adaptively downregulates interoceptive sensitivity in response to fluctuating internal states. These results have implications for understanding how spontaneous thoughts shape interoception and emotion, particularly in clinical contexts where dysregulated interoception is linked to anxiety and mood disorders. More broadly, our work underscores the need to distinguish between different forms of arousal, advancing understanding of the taxonomy and ways of measuring arousal.

Default Mode Network Functional Connectivity As a Transdiagnostic Biomarker of Cognitive Function

The default mode network (DMN) is intricately linked with processes such as self-referential thinking, episodic memory recall, goal-directed cognition, self-projection, and theory of mind. In recent years, there has been a surge in the number of studies examining its functional connectivity, particularly its relationship with frontoparietal networks involved in top-down attention, executive function, and cognitive control. The fluidity in switching between these internal and external modes of processing, which is highlighted by anticorrelated functional connectivity, has been proposed as an indicator of cognitive health. Due to the ease of estimation of functional connectivity-based measures through resting-state functional magnetic resonance imaging paradigms, there is now a wealth of large-scale datasets, paving the way for standardized connectivity benchmarks. In this review, we explore the promising role of DMN connectivity metrics as potential biomarkers of cognitive state across attention, internal mentation, mind wandering, and meditation states and investigate deviations in trait-level measures across aging and in clinical conditions such as Alzheimer's disease, Parkinson's disease, depression, attention-deficit/hyperactivity disorder, and others. We also tackle the issue of reliability of network estimation and functional connectivity and share recommendations for using functional connectivity measures as a biomarker of cognitive health.

Mindfulness as a Way of Reducing Automatic Constraints on Thought

The number of mindfulness-based wellness promotion programs offered by institutions, by governments, and through mobile apps has grown exponentially in the last decade. However, the scientific understanding of what mindfulness is and how it works is still evolving. Here, I focus on 2 common mindfulness practices: focused attention (FA) and open monitoring (OM). First, I summarize what is known about FA and OM meditation at the psychological level. While they share similar emotion regulation goals, they differ in terms of some of their attention regulation goals. Second, I turn to the neuroscientific literature, showing that FA meditation is associated with consistent activations of cortical control network regions and deactivations of cortical default network regions. In contrast, OM meditation seems to be most consistently associated with changes in the functional connectivity patterns of subcortical structures, including the basal ganglia and cerebellum. Finally, I present a novel account of the mental changes that occur during FA and OM meditation as understood from within the Dynamic Framework of Thought-a conceptual framework that distinguishes between deliberate and automatic constraints on thought. Although deliberate self-regulation processes are often emphasized in scientific and public discourse on mindfulness, here I argue that mindfulness may primarily involve changes in automatic constraints on thought. In particular, I argue that mindfulness reduces the occurrence of automatized sequences of mental states or habits of thought. In this way, mindfulness may increase the spontaneity of thought and reduce automatically constrained forms of thought such as rumination and obsessive thought.

Mindfulness Meditation and Network Neuroscience: Review, Synthesis, and Future Directions

Network neuroscience is an interdisciplinary field, which can be used to understand the brain by examining the connections between its constituent elements. In recent years, the application of network neuroscience approaches to study the intricate nature of the structural and functional relationships within the human brain has yielded unique insights into its organization. In this review, we begin by defining network neuroscience and providing an overview of the common metrics that describe the topology of human structural and functional brain networks. Then, we present a detailed overview of a limited but growing body of literature that has leveraged network neuroscience metrics to demonstrate the impact of mindfulness meditation on modulating the fundamental structural and functional network properties of segregation, integration, and influence. Although preliminary, results across studies suggest that mindfulness meditation results in a shift in connector hubs, such as the anterior cingulate cortex, the thalamus, and the mid-insula. Although there is mixed evidence regarding the impact of mindfulness training on global metrics of connectivity, the default mode network exhibits reduced intraconnectivity following mindfulness training. Our review also underscores essential directions for future research, including a more comprehensive examination of mindfulness training and its potential to influence structural and functional connections at the nodal, network, and whole-brain levels. Furthermore, we emphasize the importance of open science, adoption of rigorous study designs to improve the internal validity of studies, and the inclusion of diverse samples in neuroimaging studies to comprehensively characterize the impact of mindfulness on brain organization.

Evaluation of EEG pre-processing and source localization in ecological research

Introduction

Electroencephalography (EEG) source localization (SL) has shown potential for various applications, from epilepsy and seizure focus localization to psychiatric disorder evaluation. However, questions remain about its neurophysiological plausibility in real-world settings where only EEG signals are available without subject-specific anatomical information. This study investigates whether established pre-processing and source localization methods can produce neurophysiologically plausible activation patterns when applied to naturalistic EEG data without structural magnetic resonance imaging (MRI) or digitized electrode positions.

Methods

Proven methods are aggregated into an end-to-end pipeline that includes automatic pre-processing, eLORETA for source estimation, and a shared forward model derived from the ICBM 2009c Nonlinear Symmetric template and its corresponding CerebrA atlas. The pipeline is validated using two distinct datasets: the Healthy Brain Network (HBN) dataset comparing resting and naturalistic video-watching states and the multi-session and multi-task EEG cognitive dataset (COGBCI) comparing different cognitive workload levels. The validation approach focuses on whether the reconstructed source activations exhibit expected neurophysiological patterns via permutation testing.

Results

Findings revealed significant differences between resting state and video-watching tasks, with greater activation in posterior regions during video-watching, consistent with known visual processing pathways. The cognitive workload analysis similarly showed progressive activation increases with task difficulty, mapping to regions associated with executive function.

Discussion

These results prove that established source localization methods can produce neurophysiologically plausible activation patterns without subject-specific information, highlighting the strengths and limitations of applying these methods to mid-length naturalistic EEG data. This research demonstrates the viability of template-based source analysis for research settings where individual structural imaging is unavailable or impractical.

A reduced perception of sensory information is linked with elevated boredom in people with and without attention-deficit hyperactivity disorder

Our brains have evolved to represent and process sensory information from our environment and use it to guide behavior. The perception of sensory information and subsequent responses, such as boredom, however, vary across situations and individuals, impressively depicted by patients with attentional disorders who show extensive boredom across many situations. Despite these implications, it remains unclear how environmental features and individual traits act together to allow effective transmission of sensory information, and how both factors relate to boredom experience. We present a framework to address this issue, exposing human participants to text stimuli with defined objective information content, while assessing perceived information, boredom and text sentiment. Using information theory to formalize external and internal factors of information transmission, we find that lower information transmission predicts higher boredom. Moreover, individuals with attention deficit hyperactivity disorder show lower information transmission, compared to a control sample. Together, delineating the interaction of sensory information content with individual traits, boredom emerges as a situational consequence of reduced information-decoding, heightened in ADHD.

Hyperactive ADHD symptoms are associated with increased variability in thought content in less constrained contexts

The current study used two complementary methods to examine whether hyperactive and inattentive ADHD symptoms are differentially linked to thought dynamics under contexts that differ in the extent to which constraints are placed on ongoing thoughts. First, participants voiced aloud their thoughts in real-time (i.e., Think Aloud task), under two conditions varying in the levels of constraints exerted on their thoughts. Individuals with more hyperactive symptoms displayed heightened variability in thought content only in the less constrained condition. Second, participants completed seven days of ecological momentary assessment during which they received six thought probes daily asking the extent to which their thoughts were freely moving (as a proxy for thought content variability) and a question that captured different levels of constraints. Hyperactive symptoms were positively associated with freely moving thoughts only during responses that corresponded with lower levels of constraints. Across two approaches, we provide converging evidence that hyperactive, but not inattentive, ADHD symptoms are associated with increased thought content variability during lower levels of deliberate constraints on thoughts. Together, these results support the Dynamic Framework of Spontaneous Thought and highlight the importance of considering context in the study of thought dynamics in ADHD.

Curiosity and Mind Wandering During Music Listening Are Negatively Correlated

Curiosity, a crucial trigger of exploration and learning, has been described as the antithesis of mind wandering, a state of non-engagement with the external environment or a given task. Findings have confirmed that music's structure influences levels of curiosity in listeners as they listen and, as such, suggests that this context could be useful in examining the relationship between curiosity and mind wandering. Here, participants were exposed to extended melodies twice, during which they carried out two counterbalanced tasks: one requiring them, whenever probed, to indicate whether they had been mind wandering at that moment and the other requiring them to indicate, when probed, how curious they were feeling about the music at that moment. Critically, participants were probed at the exact same moments in the music when completing the two tasks, allowing the relationship between curiosity and mind wandering to be examined. Results confirmed our prediction of a negative relationship between curiosity and mind wandering, while exploratory analysis further suggested an influence of expertise and the music's information dynamics on patterns of mind wandering. We discuss the implications of our study for understanding music as an exploration-affording sound environment and outline directions for future work.

Detection of freely moving thoughts using SVM and EEG signals

Objective.Freely moving thought is a type of thinking that shifts from one topic to another without any overarching direction or aim. The ability to detect when freely moving thought occurs may help us promote its beneficial outcomes, such as for creative thinking and positive mood. Thus far, no studies have used machine learning to detect freely moving thought on the basis of 'objective' (e.g. neural or behavioral) data.Approach.Our study addresses this gap, using event-related potential (ERP) and spectral features of electroencephalogram (EEG) signals as well as behavioral measures during a simple attention task and machine learning to detect freely moving thought. EEG features were first examined with both inter-subject and intra-subject strategies. Specifically, the statistical and entropy features of the P3 ERP and alpha spectral measures were entered as inputs to the support vector machine. The best combination of EEG features achieving higher classification performance in both strategies were then selected to combine with behavioral features to further enhance classification performance.Main results.Our best performing model has a Matthew's correlation coefficient and area under the curve of 0.3105 and 0.6665 for inter-subject models and 0.2815 and 0.6407 for intra-subject models respectively.Significance.The above chance level performance in both strategies using EEG and behavioral features shows great promise for machine learning approaches to detect freely moving thought and highlights their potential for real-time prediction in the real world. This has important implications for enhancing creative processes and mood associated with freely moving thought.

Diminished attention network activity and heightened salience-default mode transitions in generalized anxiety disorder: Evidence from resting-state EEG microstate analysis

Generalized anxiety disorder (GAD) is a common anxiety disorder characterized by excessive, uncontrollable worry and physical symptoms such as difficulty concentrating and sleep disturbances. Although functional magnetic resonance imaging (fMRI) studies have reported aberrant network-level activity related to cognition and emotion in GAD, its low temporal resolution restricts its ability to capture the rapid neural activity in mental processes. EEG microstate analysis offers millisecond-resolution for tracking the dynamic changes in brain electrical activity, thereby illuminating the neurophysiological mechanisms underlying the cognitive and emotional dysfunctions in GAD. This study collected 64-channel resting-state EEG data from 28 GAD patients and 28 healthy controls (HC), identifying five microstate classes (A-E) in both groups. Results showed that GAD patients exhibited significantly lower duration (p < 0.01), occurrence (p < 0.05), and coverage (p < 0.01) of microstate class D, potentially reflecting deficits in attention-related networks. Such alterations may contribute to the impairments in attention maintenance and cognitive control. Additionally, GAD patients displayed reduced transition probabilities in A → D, B → D, C → D, and E → D (all corrected p < 0.05), but increased in C → E (corrected p < 0.05) and E → C (corrected p < 0.01). These results highlight a significant reduction in the brain's ability to transition into microstate class D, alongside overactivity in switching between the default mode network and the salience network. Such neurophysiological changes may underlie cognitive control deficits, increased spontaneous rumination, and emotional regulation challenges observed in GAD. Together, these insights provide a new perspective for understanding the neurophysiological and pathological mechanisms underlying GAD.

Extending homeostasis to thought dynamics for a comprehensive explanation of mind-wandering

Our thoughts are inherently dynamic, often wandering far from the current situation. Mind-wandering (MW), which is these thought transitions, is crucial for understanding the nature of human thought. Although previous research has identified various factors influencing MW, a comprehensive framework integrating these findings remains absent. Here, we propose that homeostasis has the potential to explain MW and validate the idea through simulations by replicating previous findings. We employed a homeostatic reinforcement learning model where independent drives for the task and others were assigned, and drive reduction became a reward and trained under sustained attention to the response task. To demonstrate that HRL agents can replicate key findings on MW, we had them perform a task widely used in MW research. We then analyzed their response tendencies and response times for validation. We confirmed that HRL agents behave consistently with the empirical results reported in human experiments, which suggest that MW could be under homeostatic control. Finally, we discuss the behavioral and neurobiological commonality between human thought and animal behavior and the possibility that the same principle, homeostasis, controls these phenomena.

Where is my mind? A neurocognitive investigation of mind blanking

During wakefulness, our thoughts transition between different contents. However, there are moments that are seemingly devoid of reportable content, referred to as mind blanking (MB). It remains unclear what these blanks represent, highlighting the definitional and phenomenological ambiguities surrounding MB. We map out MB in terms of its reportable expressions, neurophysiology, and relationship to adjacent phenomenology, including meditative practices and sleep. We propose a mechanistic account linking MB to changes at the physiological, neural, and cognitive levels. We suggest that ongoing experiences are characterized by degrees of richness, and that contentless events represent distinct mental states with their own diversity. We encourage future research to acknowledge MB as a reportable mental category, leading to a comprehensive understanding of ongoing experience.

Dynamic brain states underlying advanced concentrative absorption meditation: A 7-T fMRI-intensive case study

Advanced meditation consists of states and stages of practice that unfold with mastery and time. Dynamic functional connectivity (DFC) analysis of fMRI could identify brain states underlying advanced meditation. We conducted an intensive DFC case study of a meditator who completed 27 runs of jhāna advanced absorptive concentration meditation (ACAM-J), concurrently with 7-T fMRI and phenomenological reporting. We identified three brain states that marked differences between ACAM-J and nonmeditative control conditions. These states were characterized as a DMN-anticorrelated brain state, a hyperconnected brain state, and a sparsely connected brain state. Our analyses indicate higher prevalence of the DMN-anticorrelated brain state during ACAM-J than control states, and the prevalence increased significantly with deeper ACAM-J states. The hyperconnected brain state was also more common during ACAM-J and was characterized by elevated thalamocortical connectivity and somatomotor network connectivity. The hyperconnected brain state significantly decreased over the course of ACAM-J, associating with self-reports of wider attention and diminished physical sensations. This brain state may be related to sensory awareness. Advanced meditators have developed well-honed abilities to move in and out of different altered states of consciousness, and this study provides initial evidence that functional neuroimaging can objectively track their dynamics.

Connecting brain and mind through temporo-spatial dynamics: Towards a theory of common currency

Despite major progress in our understanding of the brain, the connection of neural and mental features, that is, brain and mind, remains yet elusive. In our 2020 target paper ("Is temporospatial dynamics the 'common currency' of brain and mind? Spatiotemporal Neuroscience") we proposed the "Common currency hypothesis": temporo-spatial dynamics are shared by neural and mental features, providing their connection. The current paper aims to further support and extend the original description of such common currency into a first outline of a "Common currency theory" (CCT) of neuro-mental relationship. First, we extend the range of examples to thoughts, meditation, depression and attention all lending support that temporal characteristics, (i.e. dynamics) are shared by both neural and mental features. Second, we now also show empirical examples of how spatial characteristics, i.e., topography, are shared by neural and mental features; this is illustrated by topographic reorganization of both neural and mental states in depression and meditation. Third, considering the neuro-mental connection in theoretical terms, we specify their relationship by distinct forms of temporospatial correspondences, ranging on a continuum from simple to complex. In conclusion, we extend our initial hypothesis about the key role of temporo-spatial dynamics in neuro-mental relationship into a first outline of an integrated mind-brain theory, the "Common currency theory" (CCT).

A developmental perspective on mind wandering and its relation to goal-directed thought

Mind wandering (i.e., thoughts drifting from one topic to another, with no immediate connection to the perceptual field or the ongoing task) is a widespread cognitive phenomenon. There has been increasing research interest in mind wandering in children and adolescents. However, the developmental origins of this phenomenon remain largely unknown. In the present article, I summarize the purported cognitive mechanisms of mind wandering in adults and review the empirical findings on mind wandering and automatic memory retrieval in children and adolescents. I propose a comprehensive account of the emergence of mind wandering in early and middle childhood, covering the development of its central components identified in the adult literature: motivational and emotional processes, episodic and semantic processes, perceptual decoupling, and meta-awareness. Paying special attention to the roles of developing motivation and executive control, I then address the relationship between mind wandering and goal-directed thought in children.

Effects of kynurenine pathway metabolites on choroid plexus volume, hemodynamic response, and spontaneous neural activity: A new mechanism for disrupted neurovascular communication and impaired cognition in mood disorders

Major Depressive Disorder (MDD) and Bipolar Disorder (BD) involve alterations of immune-inflammatory setpoints that activate the kynurenine pathway (KP), affecting serotoninergic and glutamatergic neurotransmission through indoleamine-2,3-dioxygenase (IDO) activity. This process produces metabolites like Kynurenine (Kyn), 3-Hydroxykynurenine (3-HK), Quinolinic acid (QuinA), and Kynurenic acid (KynA), these last two acting as agonist and antagonist at glutamatergic N-methyl-D-aspartate receptors (NMDARs), respectively. NMDARs, expressed in the choroid plexus (ChP) and arteriolar smooth muscle cells, regulate blood-brain-barrier permeability and cerebral artery dilation, suggesting that KP may influence neurovascular coupling, aligning blood flow with neural energy demand. KP's role in modulating vascular tone supports this hypothesis. Altered fractional amplitude of low-frequency fluctuations (fALFF) and disrupted default mode network (DMN) activity in mood disorders are linked to cognitive deficits possibly through neurovascular uncoupling like in neurological diseases. This makes fALFF and hemodynamic response function (HRF) potential indicators of these changes. We investigated KP associations with ChP volumes, functional-MRI at rest measures like spontaneous neural activity (fALFF) and hemodynamic response function (HRF) parameters within the default mode network (DMN), and cognitive performance in 42 MDD and 36 BD inpatients experiencing a depressive episode. Results revealed that lower QuinA/KynA ratios and higher KynA levels predict larger ChP volumes. Higher KYN and 3-HK levels, along with lower KynA levels, were associated with increased DMN fALFF and shorter time-to-peak (TTP) in HRF, suggesting altered neurovascular coupling. Mediation analyses indicated that KP metabolites influenced cognitive performance through their effects on resting state measures, affecting global cognitive functioning score, verbal fluency, and psychomotor coordination. These findings suggest that KP metabolites modulate brain function and structure via NMDAR-mediated pathways and vascular-based mechanisms, offering insights into the cognitive impairments observed in mood disorders and identifying potential therapeutic targets.

States of mind: Towards a common classification of mental states

Thanks to the wealth of studies on mind-wandering, the stream of thought has now become, again, the focus of mainstream investigations in cognitive psychology. Yet, how one should describe and measure the stream of thought is still very much left undecided. Here, we approach the problem through the notion of mental states. Based on conceptual analysis and previous empirical data, we identify five states: focus, task-related interference, external distraction, daydream, and blank. We ask the question whether this classification (the Classification of Mental States - CoMS-5T) - provides an adequate partition of mental states. To do so, first, we rely on participants' free verbal reports of their mental contents, that were then classified off-line by external raters. We provide evidence for the construct validity of the CoMS-5T and for its neutrality, in the sense that it does bias participants' reports. Second, we provide evidence for the criterion validity of the CoMS-5T: by means of a reanalysis of a large data set made available by Beikmohamadi and Meier (2022), we find distinct behavioural signatures for four of the five states in the CoMS.

Dynamic cycles between brain states during creative storytelling

Many theories suggest that creative thinking involves a dynamic transition between different mental states, yet empirical evidence supporting this notion remains scarce. The dual process model proposes that spontaneous thinking and deliberate thinking drive the dwell in and the transitions between different mental states during creative thinking, but there is a debate over whether the two types of thinking operate in parallel or in sequence. To address these gaps, we conducted a functional magnetic resonance imaging (fMRI) study in 41 college students during a creative storytelling task. We then compared the dynamic brain states in creative versus uncreative storytelling to identify key brain states associated with creative thinking. And we further performed correlation analysis between these key brain states with performance of various creative tasks, trying to link the key brain states with different cognitive processes. The results showed that two key brain states are associated with creative thinking, with one involving whole-brain synchronization and the other involving the synchronization of four networks, including the default mode network and the control network. The transition patterns between the key brain states provide tentative evidence for dynamic circulation between different mental states during creative storytelling. Using a deep learning approach, we demonstrate an alternating interaction between spontaneous and deliberate thinking, driving dwelling in and the transitions between different brain states. These findings deepen our understanding of the cognitive and neural mechanisms underlying creative thinking.

Mind wandering enhances statistical learning

The human brain spends 30-50% of its waking hours engaged in mind-wandering (MW), a common phenomenon in which individuals either spontaneously or deliberately shift their attention away from external tasks to task-unrelated internal thoughts. Despite the significant amount of time dedicated to MW, its underlying reasons remain unexplained. Our pre-registered study investigates the potential adaptive aspects of MW, particularly its role in predictive processes measured by statistical learning. We simultaneously assessed visuomotor task performance as well as the capability to extract probabilistic information from the environment while assessing task focus (on-task vs. MW). We found that MW was associated with enhanced extraction of hidden, but predictable patterns. This finding suggests that MW may have functional relevance in human cognition by shaping behavior and predictive processes. Overall, our results highlight the importance of considering the adaptive aspects of MW, and its potential to enhance certain fundamental cognitive abilities.

Multiple brain activation patterns for the same perceptual decision-making task

Meaningful variation in internal states that impacts cognition and behavior remains challenging to discover and characterize. Here we leverage trial-to-trial fluctuations in the brain-wide signal recorded using functional MRI to test if distinct sets of brain regions are activated on different trials when accomplishing the same task. Across three different perceptual decision-making experiments, we estimate the brain activations for each trial. We then cluster the trials based on their similarity using modularity-maximization, a data-driven classification method. In each experiment, we find multiple distinct but stable subtypes of trials, suggesting that the same task can be accomplished in the presence of widely varying brain activation patterns. Surprisingly, in all experiments, one of the subtypes exhibits strong activation in the default mode network, which is typically thought to decrease in activity during tasks that require externally focused attention. The remaining subtypes are characterized by activations in different task-positive areas. The default mode network subtype is characterized by behavioral signatures that are similar to the other subtypes exhibiting activation with task-positive regions. These findings demonstrate that the same perceptual decision-making task is accomplished through multiple brain activation patterns.

The individual determinants of morning dream recall

Evidence suggests that (almost) everyone dreams during their sleep and may actually do so for a large part of the night. Yet, dream recall shows large interindividual variability. Understanding the factors that influence dream recall is crucial for advancing our knowledge regarding dreams' origin, significance, and functions. Here, we tackled this issue by prospectively collecting dream reports along with demographic information and psychometric, cognitive, actigraphic, and electroencephalographic measures in 217 healthy adults (18-70 y, 116 female participants, 101 male participants). We found that attitude towards dreaming, proneness to mind wandering, and sleep patterns are associated with the probability of reporting a dream upon morning awakening. The likelihood of recalling dream content was predicted by age and vulnerability to interference. Moreover, dream recall appeared to be influenced by night-by-night changes in sleep patterns and showed seasonal fluctuations. Our results provide an account for previous observations regarding inter- and intra-individual variability in morning dream recall.

Infraslow Dynamic Patterns in Human Cortical Networks Track a Spectrum of External to Internal Attention

Early efforts to understand the human cerebral cortex focused on localization of function, assigning functional roles to specific brain regions. More recent evidence depicts the cortex as a dynamic system, organized into flexible networks with patterns of spatiotemporal activity corresponding to attentional demands. In functional MRI (fMRI), dynamic analysis of such spatiotemporal patterns is highly promising for providing non-invasive biomarkers of neurodegenerative diseases and neural disorders. However, there is no established neurotypical spectrum to interpret the burgeoning literature of dynamic functional connectivity from fMRI across attentional states. In the present study, we apply dynamic analysis of network-scale spatiotemporal patterns in a range of fMRI datasets across numerous tasks including a left-right moving dot task, visual working memory tasks, congruence tasks, multiple resting state datasets, mindfulness meditators, and subjects watching TV. We find that cortical networks show shifts in dynamic functional connectivity across a spectrum that tracks the level of external to internal attention demanded by these tasks. Dynamics of networks often grouped into a single task positive network show divergent responses along this axis of attention, consistent with evidence that definitions of a single task positive network are misleading. Additionally, somatosensory and visual networks exhibit strong phase shifting along this spectrum of attention. Results were robust on a group and individual level, further establishing network dynamics as a potential individual biomarker. To our knowledge, this represents the first study of its kind to generate a spectrum of dynamic network relationships across such an axis of attention.

Variations of autonomic arousal mediate the reportability of mind blanking occurrences

Mind blanking (MB) is the inability to report mental events during unconstraint thinking. Previous work shows that MB is linked to decreased levels of cortical arousal, indicating dominance of cerebral mechanisms when reporting mental states. What remains inconclusive is whether MB can also ensue from autonomic arousal manipulations, pointing to the implication of peripheral physiology to mental events. Using experience sampling, neural, and physiological measurements in 26 participants, we first show that MB was reported more frequently in low arousal conditions, elicited by sleep deprivation. Also, there was partial evidence for a higher occurence of MB reports in high arousal conditions, elicited by intense physical exercise. Transition probabilities revealed that, after sleep deprivation, mind wandering was more likely to be followed by MB and less likely to be followed by more mind wandering reports. Using classification schemes, we found higher performance of a balanced random forest classifier trained on both neural and physiological markers in comparison to performance when solely neural or physiological were used. Collectively, we show that both cortical and autonomic arousal affect MB report occurrences. Our results establish that MB is supported by combined brain-body configurations, and, by linking mental and physiological states, they pave the way for novel embodied accounts of spontaneous thinking.'The stage 1 protocol for this Registered Report was accepted in principle on 02/01/23. The protocol, as accepted by the journal, can be found at: 10.17605/OSF.IO/SH2YE' Techniques: Life sciences techniques, Biophysical methods [Electrocardiography - EKG]; Life sciences techniques, Biophysical methods [Electroencephalography - EEG]; CTS received date: 27.11.2024.

Spontaneous thought separates into clusters of negative, positive, and flexible thinking

The nature and frequency of spontaneous thoughts play a critical role in cognitive processes like perception, decision-making, attention, and memory. Deficits in these processes are also greatly associated with the development and maintenance of psychopathology. However, the underlying cognitive dynamics of free and stuck spontaneous thought remain unclear, as these often occur in the absence of measurable behaviors. Here, we analyze free word-association data using attractor-state dynamic modeling, which conceptualizes stuck spontaneous thought as navigating a multidimensional semantic space while in the presence of strong attractor locations. Word-association data was collected from an exploratory sample (N1 = 65), a first replication sample (N2 = 79), and, following pre-registration, a second replication sample (N3 = 222). After the data was embedded into a 3-dimensional semantic space and fit by our dynamic model, unsupervised learning consistently grouped data into four clusters across all independent samples. These clusters were characterized by two distinct patterns of stuck negative thinking, a pattern of protective positive thinking, and a pattern of flexible mind-wandering. Our results support a method for modeling spontaneous thought and isolate distinct sub-types that may not be accessible using retrospective self-report methods. We discuss implications for clinical and cognitive science.

Increased default mode network activation in depression and social anxiety during upward social comparison

Social comparisons are a core feature of human life. Theories posit that social comparisons play a critical role in depression and social anxiety triggering negative evaluations about the self, as well as negative emotions. We investigated the neural basis of social comparisons in participants with major depression and/or social anxiety (MD-SA, n = 56) and healthy controls (n = 47) using functional magnetic resonance imaging. While being scanned participants performed a social comparison task, during which they received feedback about their performance and the performance of a coplayer. Upward social comparisons (being worse than the coplayer) elicited high levels of negative emotions (shame, guilt, and nervousness) across participants, with this effect being enhanced in the MD-SA group. Notably, during upward comparison the MD-SA group showed greater activation than the control group in regions of the default mode network (DMN). Specifically, for upward comparison MD-SA participants demonstrated increased activation in the dorsomedial prefrontal cortex and reduced deactivation in the posteromedial cortex, regions linked to self-referential processing, inferences about other people's thoughts, and rumination. Findings suggest that people with depression and social anxiety react to upward comparisons with a more negative emotional response, which may be linked to introspective processes related to the DMN.

Dynamic reconfiguration of default and frontoparietal network supports creative incubation

Although creative ideas often emerge during distraction activities unrelated to the creative task, empirical research has yet to reveal the underlying neurocognitive mechanism. Using an incubation paradigm, we temporarily disengaged participants from the initial creative ideation task and required them to conduct two different distraction activities (moderately-demanding: 1-back working memory task, non-demanding: 0-back choice reaction time task), then returned them to the previous creative task. On the process of creative ideation, we calculated the representational dissimilarities between the two creative ideation phases before and after incubation period to estimate the neural representational change underlying successful incubation. The results found that, for the 0-back condition, successful incubation was associated with the representational change in precuneus (PCU), whereas for the 1-back condition, it was associated with change in rostrolateral PFC (rlPFC), suggesting the dual processes of the DMN-mediated associative thinking and PFC-mediated controlled thinking for the 0- or the 1-back incubation conditions to prompt creation. On the incubation delay, we found the successful incubation in both conditions was accompanied with network integration between frontoparietal (FP) and default mode (DM) network, further suggesting the coupling of the controlled- and associative-thinking for the incubation to work. Moreover, we found the FP-DM integration during incubation period could respectively predict the representational change in PCU or rlPFC in the creative ideation phase of 0- or 1-back condition. This means both conditions benefits from the coordination of the controlled and of the associative thinking in incubation period, but for the representational change in creative ideation phase, 1-back condition relies more on the controlled thinking, whereas the 0-back on the associative ones. Additionally, we created a neural encoding indicator to assess the degree to which temporal activities in the rlPFC or PCU during incubation delay is related to the after-incubation successful problem-solving, and we found a positive relation between this indicator and dynamic reconfiguration of brain networks. This further indicates that FP-DM integration supports creative incubation through offline processing.

Effective engagement in computerized cognitive training for older adults

Computerized cognitive training (CCT) is a frontline therapy to prevent or slow age-related cognitive decline. A prerequisite for CCT research to provide clinically relevant improvements in cognition is to understand effective engagement, i.e., the pattern of energy investment that ensures CCT effectiveness. Even though previous studies have assessed whether particular variables (e.g., gamification) predict engagement and/or CCT effectiveness, the field lacks a systematic approach to understanding effective engagement. Here, by comprehensively reviewing and evaluating engagement and adjacent literature, we propose a standardized measurement and operational framework to promote effective engagement with CCT targeting cognitive decline in older adults. We suggest that promoting effective engagement with CCT has two key steps: 1) comprehensively measuring engagement with CCT and 2) identifying which aspects of engagement are essential to achieve the pre-specified outcome of clinically relevant improvements in cognition. The proposed measurement and operational framework of effective engagement will allow future research to maximize older adults' engagement with CCT to slow/prevent age-related cognitive decline.

Opening the black box: Think Aloud as a method to study the spontaneous stream of consciousness

Asking participants to Think Aloud is a common method for studying conscious experience, but it remains unclear whether this approach alters thought qualities-such as meta-awareness, rate of topic shifts, or the content of thoughts in task-absent conditions. To investigate this, we conducted two studies comparing thinking aloud to thinking silently. In Study 1, 111 participants alternated between 15-minute intervals of verbalizing and silently reflecting on their stream of consciousness in a counterbalanced design. A subset also reported topic shifts intermittently via self- and probe-catching methods. Results showed that the stream of consciousness was minimally reactive to the Think Aloud protocol, with no significant differences in meta-awareness and topic shifting rates. Moreover, among 21 thought qualities and 18 content topics analyzed, only three qualities (private thoughts, mind blanking, and session difficulty) and one topic (partner, intimacy, love, and sexual matters) differed between Think Aloud and Silent Think. In Study 2, 102 participants either did Think Aloud or Silent Think while responding to thought probes. Findings replicated the lack of differences in the frequency and meta-awareness of topic shifts between Think Aloud and Silent Think. Furthermore, no differences in reported cognitive load were observed between the two conditions. These results emphasize the value of the Think Aloud procedure for examining the stream of consciousness, demonstrating its reliability and minimal impact on the natural flow of thoughts. Thus, Think Aloud offers a robust model system for examining the otherwise unverbalized stream of consciousness in task-absent contexts.

Multimodal creativity assessments following acute and sustained microdosing of lysergic acid diethylamide

INTRODUCTION

Enhanced creativity is often cited as an effect of microdosing (taking repeated low doses of a psychedelic drug). There have been recent efforts to validate the reported effects of microdosing, however creativity remains a difficult construct to quantify.

OBJECTIVES

The current study aimed to assess microdosing's effects on creativity using a multimodal battery of tests as part of a randomised controlled trial of microdosing lysergic acid diethylamide (LSD).

METHODS

Eighty healthy adult males were given 10 µg doses of LSD or placebo every third day for six weeks (14 total doses). Creativity tasks were administered at a drug-free baseline session, at a first dosing session during the acute phase of the drug's effects, and in a drug-free final session following the six-week microdosing regimen. Creativity tasks were the Alternate Uses Test (AUT), Remote Associates Task (RAT), Consensual Assessment Technique (CAT), and an Everyday Problem-Solving Questionnaire (EPSQ).

RESULTS

No effect of drug by time was found on the AUT, RAT, CAT, or EPSQ. Baseline vocabulary skill had a significant effect on AUT and RAT scores.

CONCLUSIONS

Despite participants reporting feeling more creative on dose days, objective measurement found no acute or durable effects of the microdosing protocol on creativity. Possible explanations of these null findings are that laboratory testing conditions may negatively affect ability to detect naturalistic differences in creative performance, the tests available do not capture the facets of creativity that are anecdotally affected by microdosing, or that reported enhancements of creativity are placebo effects.

Resting-state BOLD temporal variability of the default mode network predicts spontaneous mind wandering, which is negatively associated with mindfulness skills

Mind wandering (MW) encompasses both a deliberate and a spontaneous disengagement of attention from the immediate external environment to unrelated internal thoughts. Importantly, MW has been suggested to have an inverse relationship with mindfulness, a state of nonjudgmental awareness of present-moment experience. Although they are, respectively, associated with increased and decreased activity in the default mode network (DMN), the specific contributions of deliberate and spontaneous MW, and their relationships with mindfulness abilities and resting-state macro networks remain to be elucidated. Therefore, resting-state MRI scans from 76 participants were analyzed with group independent component analysis to decompose brain networks into independent macro-networks and to see which of them predicted specific aspects of spontaneous and deliberate MW or mindfulness traits. Our results show that temporal variability of the resting-state DMN predicts spontaneous MW, which in turn is negatively associated with the acting with awareness facet of mindfulness. This finding shows that the DMN is not directly associated with overall mindfulness, but rather demonstrates that there exists a close relationship between DMN and MW, and furthermore, that the involvement of mindfulness abilities in this dynamic may be secondary. In sum, our study contributes to a better understanding of the neural bases of spontaneous MW and its relationship with mindfulness. These results open up the possibility of intervening on specific aspects of our cognitive abilities: for example, our data suggest that training the mindfulness facet acting with awareness would allow lessening our tendency for MW at inopportune times.