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.

One of the most striking features of human consciousness is its ability to foster an ongoing, seemingly continuous stream of thought. Prior studies have provided valuable insights into the neural correlates of the content of thought (e.g., whether it is task related or not). However, independent of its content, the stream of thought can also be characterized by its dynamics—how it changes over time. The Dynamic Framework of Thought proposes a neural model of how different large-scale brain networks may contribute to thoughts that are freely moving (spontaneous) or deliberately constrained. We empirically tested this model using a neurophenomenological approach, in which participants reported the nature of their thought stream in real time during fMRI scanning. Consistent with the model predictions, freely-moving thought was associated with greater activation of the default network (especially the medial-temporal subcomponent) than the frontoparietal control network, whereas deliberately constrained thought was associated with the opposite pattern of activation. Additionally, these distinct thought dynamics were reflected in the changes in the functional coupling patterns within and between these networks. These findings suggest that experience sampling, in conjunction with fMRI, can illuminate the neural basis of subtle thought dynamics.

The flow of thought is persistent, and at times merciless. Mental content is generated throughout the day and into the night, moving forward predictably at times but surprisingly at others. Understanding what influences the trajectory of thought—how thoughts continuously unfold over time—has important implications for the diagnosis and treatment of thought disorders like schizophrenia and recurrent nightmares. Here, we examine whether cognitive control restricts moment-to-moment content shifts across sleep and wakefulness, thus acting as a fundamental constraint on thought variability. Thought variability was measured as the semantic incoherence between sequential thought phrases and was applied to independent datasets of dreaming and waking reports. Our results show that within both sleeping and waking reports, conditions typically marked by higher levels of cognitive control were associated with decreased thought variability (i.e., semantic incoherence). During wakefulness, on-task conditions were associated with reduced levels of thought variability compared to off-task conditions, and thought variability was greater when thoughts wandered around more freely. During sleep, lucid dreams, marked by higher levels of cognitive control, were associated with reduced levels of thought variability compared to non-lucid dreams. Together, these results suggest that cognitive control may limit thought variability across the 24-hour cycle of thought generation. Such findings are consistent with the Dynamic Framework of Thought, where mental states are expected to vary on a continuum of deliberate constraints, with lower cognitive control leading to a categorical cluster of spontaneous thought processes that includes both mind-wandering during wakefulness and non-lucid dreams during sleep. This observation has broad implications for models of cognition, specifically highlighting the continuity of cognitive processes throughout the circadian cycle and the importance of considering varying levels of thought constraint in both waking and dreaming states.

People spend a remarkable 30–50% of their 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 well-being 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. In this Perspective, Kucyi and co-authors explore some of the recent developments in neuroscience, including investigations of network dynamics and neural mechanisms that support off-task thoughts, and consider the implications for maladaptive forms of thought in mental health.

Involuntary thinking occurs when mental states arise without intention. Such thoughts can take different forms, such as involuntary autobiographical memories (IAM), ruminative thoughts, and unexpected thoughts-all of which are popular areas of study, albeit in somewhat disparate literatures. Despite these mental states sharing a common thread of feeling involuntary in nature, it is nevertheless unclear what separates them phenomenologically. We conducted a set of exploratory and confirmatory experiments to elucidate the appraisal dimensions behind these forms of involuntary thought, with a particular interest in understanding the phenomenology behind unexpected thoughts that are predicted to violate expectations of both timing and content. Across two experiments, we found that unexpected thoughts had unique appraisal structures compared to the other two forms of involuntary thought: they were less identifiably cued, more surprising in content and timing, and offered new information (i.e., insight). We discuss how these distinctions support recent theories regarding the nature of unexpected thought and its relation to other forms of involuntary thinking, namely IAM and ruminative thought, which are the more commonly studied forms of involuntary thinking.

Creative thinking is often viewed as a dynamic process that involves shifts between two distinct modes (or phases) of thought – a generative and an evaluative mode. The generative mode involves the generation of new ideas, whereas the evaluative mode involves cognitive and affective evaluations of these ideas. Although the neurocognitive underpinnings of these two thought modes have received significant attention, the dynamics of transitions between them have remain largely unexplored. Here, we focus on these dynamics and review current evidence from psychology and cognitive neuroscience about the relationships and transitions between the two purported modes of thought. We suggest that two types of evaluative processing—automatic-affective and deliberate (i.e., based in cognitive control)—play pivotal roles in supporting transitions between the generative and evaluative modes. Ultimately, we contend that future research into creative thought should focus on clarifying the timescales at which the two modes of thought may unfold, how the transition rate between them may relate to creative outcomes, and the nature of automatic-affective evaluations made towards thoughts.

Off-task thought has been found to occur at high rates and is related to impairment in ADHD. However, off-task thought is heterogenous and it remains unclear which specific dimensions of off-task thought are more prevalent in this disorder. It is therefore important to dissociate different aspects of off-task thought in order to better understand the mechanisms underlying impairment. The current study focused on the dimension of constrained (focused) to freely moving off-task thought. Self-report and neurophysiological measures during a computerized attention tasks provided convergent evidence that individuals with ADHD not only have more off-task thought than those without, but also engaged in a greater proportion of freely moving off-task thought than non-ADHD controls. Overall, this work demonstrated differences in both the quantity and type of off-task thought in adults with ADHD. It provides novel insight into both the phenomenology of off-task thought, as well as potential mechanisms underlying impairment in ADHD.

Much of our knowledge about the correlates of mind-wandering comes from assessing task-unrelated thought. Less is known about the correlates of freely moving thought, a dimension that assesses the degree to which thoughts arise and unfold with low levels of guidance or constraints. Task-unrelated thought is consistently associated with more negative affective valence compared with being on task; however, it is unclear whether freely moving thought shares the same relationship with affect. We conducted two ecological momentary assessment studies in the context of everyday life and found that the two dimensions have different affective correlates. In Study 1, task-unrelated thought was associated with less positive concurrent valence than being on-task. However, freely moving thought was associated with more positive concurrent valence and was predictive of more positive valence at a subsequent timepoint. Freely moving thought, but not task-unrelated thought, also positively predicted concurrent arousal. Computational sentiment analyses of participants' thought descriptions offered convergent evidence of differential relationships between the two thought dimensions and affect. Study 2 used different measurement scales to assess whether (a) the pattern of findings replicated and (b) if the effects were robust to changes in measurement. The main findings were replicated: task-unrelated thought was negatively associated with concurrent valence, whereas freely moving thought was positively associated with concurrent valence. However, freely moving thought did not predict subsequent valence and was not related to concurrent arousal. The most robust findings related to concurrent valence. Although mind-wandering has acquired a relatively negative reputation to date, our findings suggest that there might be positive aspects that remain unexplored. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Although central to well-being, functional and dysfunctional thoughts arise and unfold over time in ways that remain poorly understood. To shed light on these mechanisms, we adapted a "think aloud" paradigm to quantify the content and dynamics of individuals' thoughts at rest. Across two studies, external raters hand coded the content of each thought and computed dynamic metrics spanning duration, transition probabilities between affective states, and conceptual similarity over time. Study 1 highlighted the paradigm's high ecological validity and revealed a narrowing of conceptual scope following more negative content. Study 2 replicated Study 1's findings and examined individual difference predictors of trait brooding, a maladaptive form of rumination. Across individuals, increased trait brooding was linked to thoughts rated as more negative, past-oriented and self-focused. Longer negative and shorter positive thoughts were also apparent as brooding increased, as well as a tendency to shift away from positive conceptual states, and a stronger narrowing of conceptual scope following negative thoughts. Importantly, content and dynamics explained independent variance, accounting for a third of the variance in brooding. These results uncover a real-time cognitive signature of rumination and highlight the predictive and ecological validity of the think aloud paradigm applied to resting state cognition.

Thoughts that appear to come to us ‘out of the blue’ or ‘out of nowhere’ are a familiar aspect of mental experience. Such thoughts tend to elicit feelings of surprise and spontaneity. Although we are beginning to understand the neural processes that underlie the arising of such thoughts, little is known about what accounts for their peculiar phenomenology. Here, we focus on one central aspect of this phenomenology—the experience of surprise at their occurrence, as it relates to internal probabilistic predictions regarding mental states. We introduce a distinction between two phenomenologically different types of transitions in thought content: (i) abrupt transitions, which occur at surprising times but lead to unsurprising thought content, and (ii) wayward transitions, which occur at surprising times and also lead to surprising thought content. We examine these two types of transitions using a novel approach that combines probabilistic and predictive processing concepts and principles. We employ two different probability metrics—transition and occurrence probability—to characterize and differentiate between abrupt and wayward transitions. We close by discussing some potentially beneficial ways in which these two kinds of transitions in thought content may contribute to mental function, and how they may be implemented at the neural level. This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation’.

Individuals use various strategies to cope with challenging emotions such as anxiety. Mindful acceptance involves broadening attentional scope and fully experiencing present moment sensory feelings (whether pleasant or unpleasant) without judgment or elaboration. In contrast, narrative-evaluation involves focusing on a narrow band of sensory experience and generating an elaborate narrative about the meaning and desirability of one’s emotional feelings. The current study examined brain network organization during these strategies using graph theoretic analyses. We used a naturalistic task paradigm in which participants reflected on an anxiety-provoking issue from their personal lives and adopted each strategy in different blocks. Compared to narrative-evaluation, mindful acceptance was associated with: (i) increased global network connectivity; (ii) greater integration of interoceptive regions (mid and posterior insula) into large-scale networks; (iii) reorganization of motivational circuits including a shift in the striatum’s network assignment from the default network to the salience network; and (iv) a shift from default network to frontoparietal control network (FPCN) regions as central hubs that coordinate information flow. Functional connectivity patterns within the left FPCN were associated with acceptance reports. Thus, broadening attentional scope during mindful acceptance is supported by a more globally interconnected neural landscape, as well as greater information flow through FPCN regions that underlie metacognitive awareness and cognitive control.

Abstract Psychotherapy holds great promise for bringing about therapeutic change, yet a major challenge lies in translating short-term change into change that endures over extended time scales. This chapter tackles the “how-tos” of therapeutic change through the lens of an emerging field of research on internally guided experience, encapsulating thoughts and feelings. The authors first synthesize basic science and clinical research on functional and dysfunctional internal thought, highlighting the importance of alterations in content, processes and corresponding patterns of functional activity and connectivity of the brain’s default network. Next, they introduce a neurocognitive model highlighting spontaneous processes, deliberate processes, and automatic affective processes that promote and inhibit the dynamics of thought. They apply this dynamic framework to understanding mechanisms of change associated with common psychotherapies and review preliminary effects of therapy on brain activity and connectivity within and between large-scale brain networks. Throughout the chapter, the authors note many points of convergence with the integrated memory model, which inspired the edited volume to which this chapter belongs.

Contemporary investigations regard creativity as a dynamic form of cognition that involves movement between the dissociable stages of creative generation and creative evaluation. Our recently proposed Dynamic Framework of Thought (Christoff et al., 2016) offered a conceptualization of these stages in terms of an interplay between sources of constraint and variability on thought. This initial conceptualization, however, has yet to be fully explicated and given targeted discussion. Here, we refine this framework's account of creativity by highlighting the dynamic nature of creative thought, both within and between the stages of creative generation and evaluation. In particular, we emphasize that creative generation in particular is best regarded as a product of multiple, varying mental states, rather than being a singular mental state in and of itself. We also propose that the psychedelic state is a mental state with high potential for facilitating creative generation and update the Dynamic Framework of Thought to incorporate this state. This paper seeks to highlight the dynamic nature of the neurocognitive processes underlying creative thinking and to draw attention to the potential utility of psychedelic substances as experimental tools in the neuroscience of creativity.

Recent applications of dynamic network analyses to functional neuroimaging data have revealed relationships between a number of cognition conditions and the dynamic reconfiguration of brain networks. Here we critically review such applications of network neuroscience to intelligence. After providing an overview of network neuroscience, we center our discussion around the recently proposed Network Neuroscience Theory of Intelligence (Barbey, 2017). We evaluate and review existing empirical support for the theses made by this theory and argue that while studies strongly suggest their plausibility, evidence to date has largely been indirect. We propose avenues for future research to directly evaluate these theses by overcoming the methodological and analytical shortcomings of previous studies. In doing so, our goal is to stimulate future empirical investigations and present valuable ways forward in the network neuroscience of intelligence.

Recent applications of dynamic network analyses to functional neuroimaging data have revealed relationships between a number of cognition conditions and the dynamic reconfiguration of brain networks. Here we critically review such applications of network neuroscience to intelligence. After providing an overview of network neuroscience, we center our discussion around the recently proposed Network Neuroscience Theory of Intelligence (Barbey, 2017). We evaluate and review existing empirical support for the theses made by this theory and argue that while studies strongly suggest their plausibility, evidence to date has largely been indirect. We propose avenues for future research to directly evaluate these theses by overcoming the methodological and analytical shortcomings of previous studies. In doing so, our goal is to stimulate future empirical investigations and present valuable ways forward in the network neuroscience of intelligence.

Despite increasing scientific interest in self-generated thought—mental content largely independent of the immediate environment—there has yet to be any comprehensive synthesis of the subjective experience and neural correlates of affect in these forms of thinking. Here, we aim to develop an integrated affective neuroscience encompassing many forms of self-generated thought—normal and pathological, moderate and excessive, in waking and in sleep. In synthesizing existing literature on this topic, we reveal consistent findings pertaining to the prevalence, valence, and variability of emotion in self-generated thought, and highlight how these factors might interact with self-generated thought to influence general well-being. We integrate these psychological findings with recent neuroimaging research, bringing attention to the neural correlates of affect in self-generated thought. We show that affect in self-generated thought is prevalent, positively biased, highly variable (both within and across individuals), and consistently recruits many brain areas implicated in emotional processing, including the orbitofrontal cortex, amygdala, insula, and medial prefrontal cortex. Many factors modulate these typical psychological and neural patterns, however; the emerging affective neuroscience of self-generated thought must endeavor to link brain function and subjective experience in both everyday self-generated thought as well as its dysfunctions in mental illness.

Spontaneous thought has recently been defined as a state of reduced constraints on the mind, and it encompasses a range of experiences such as mind-wandering, day and night dreaming, creative idea generation, and others. While its day-to-day benefits have been explored for some time, its clinical implications have been understudied, and for the most part have been limited to potential detrimental effects on mood. We propose that spontaneous thought has a wider variety of clinical effects, as well as a number of potential therapeutic benefits—affording the opportunity to address suppressed or repressed material, facilitating therapeutic insights, and promoting general relaxation. Its unconstrained mode may not be without clinical risks, however. Within literature discussing meditation, sleep, relaxation, and sensory deprivation—activities that promote unconstrained attention—evidence suggests that some individuals may become destabilized, or face a worsening of symptoms in some circumstances. More research needs to be done to clarify the mediating factors that could result in these divergent outcomes.