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Rumination is a cognitive style characterized by repetitive thoughts about one's negative internal states and is a common symptom of depression. Previous studies have linked trait rumination to alterations in the default mode network, but predictive brain markers of rumination are lacking. Here, we adopt a predictive modeling approach to develop a neuroimaging marker of rumination based on the variance of dynamic resting-state functional connectivity and test it across 5 diverse subclinical and clinical samples (total n = 288). A whole-brain marker based on dynamic connectivity with the dorsomedial prefrontal cortex (dmPFC) emerges as generalizable across the subclinical datasets. A refined marker consisting of the most important features from a virtual lesion analysis further predicts depression scores of adults with major depressive disorder (n = 35). This study highlights the role of the dmPFC in trait rumination and provides a dynamic functional connectivity marker for rumination. Rumination, which is the tendency to dwell on negative internal states repetitively, is a well-known cognitive style associated with depression. The authors developed a predictive model of rumination and observed that the dorsomedial prefrontal cortex plays an important role in rumination. [ABSTRACT FROM AUTHOR]

Clinical theories of adaptation in bereavement highlight a need for flexible shifting between mental states. However, prolonged motivational salience of the deceased partner may be a complicating factor, particularly when coupled with perseverative thinking about the loss. We investigated how prolonged grief symptoms might relate to resting state functional brain network connectivity in a sample of older adults (n = 38) who experienced the death of a partner 6–36 months prior, and whether intranasal oxytocin (as a neuropeptide involved in pair‐bonding) had differential effects in participants with higher prolonged grief symptoms. Higher scores on the Inventory of Complicated Grief (ICG) were associated with lower anticorrelation (i.e., higher functional connectivity) between the defaultretrosplenial – cingulo‐operculardACC network pair. Intranasal oxytocin increased functional connectivity in the same defaultretrosplenial – cingulo‐operculardACC circuit but ICG scores did not moderate effects of oxytocin, contrary to our prediction. Higher ICG scores were associated with longer dwell time in a dynamic functional connectivity state featuring positive correlations among default, frontoparietal, and cingulo‐opercular networks, across both placebo and oxytocin sessions. Dwell time was not significantly affected by oxytocin, and higher prolonged grief symptoms were not associated with more variability in dynamic functional connectivity states over the scan. Results offer preliminary evidence that prolonged grief symptoms in older adults are associated with patterns of static and time‐varying functional network connectivity and may specifically involve a default network‐salience‐related circuit that is sensitive to oxytocin. [ABSTRACT FROM AUTHOR]

The article discusses research on how self-generated concepts in spontaneous thought construct inner affective states and idiosyncrasies. The functional magnetic resonance imaging experiment was conducted to examine brain representations and dynamics of self-generated concepts using a newly developed free association–based thought sampling task. Results show that the neural representations of valence became more person-specific as the level of perceived self-relevance increased.

Many individuals spend a significant amount of their time "mind‐wandering". Mind‐wandering often includes spontaneous, nonintentional thought, and a neural correlate of this kind of thought is the default mode network (DMN). Thoughts during mind‐wandering can have positive or negative valence, but only little is known about the neural correlates of positive or negative thoughts. We used resting‐state functional magnetic resonance imaging (fMRI) and music to evoke mind‐wandering in n = 33 participants, with positive‐sounding music eliciting thoughts with more positive valence and negative‐sounding music eliciting thoughts with more negative valence. Applying purely data‐driven analysis methods, we show that medial orbitofrontal cortex (mOFC, part of the ventromedial prefrontal cortex) and the posterior cingulate sulcus (likely area 23c of the posterior cingulate cortex), two sub‐regions of the DMN, modulate the valence of thought‐contents during mind‐wandering. In addition, across two independent experiments, we observed that the posterior cingulate sulcus, a region involved in pain, shows valence‐specific functional connectivity with core regions of the brain's putative pain network. Our results suggest that two DMN regions (mOFC and posterior cingulate sulcus) support the formation of negative spontaneous, nonintentional thoughts, and that the interplay between these structures with regions of the putative pain network forms a neural mechanism by which thoughts can become painful. [ABSTRACT FROM AUTHOR]

Although task-unrelated thinking (often conceptualised as "mind-wandering") has been increasingly investigated in recent years, the content and correlates of everyday off-task thought in clinical disorders, particularly anxiety disorders, remain poorly understood. We aimed to address this gap by using ecological momentary assessment to assess off-task and on-task thoughts in adults with social anxiety disorder (SAD) and demographically matched controls. Findings showed that individuals with SAD more frequently engaged in internally oriented off-task thinking than healthy controls, but not externally oriented off-task thinking. Compared to thoughts focused on the task at hand, adults with SAD rated their internal off-task thoughts as less controllable, more self-focused, and as associated with worse mood than controls. However, when the SAD group was focused on the task at hand, group differences disappeared. Daily findings were paralleled by higher scores in SAD on a trait measure of unintentional, but not intentional, mind-wandering. In sum, the content and mood correlate of internally oriented off-task thoughts depended on the presence of clinical anxiety. In addition, focusing on the task at hand normalised thought content and mood in SAD, highlighting a window for intervention. [ABSTRACT FROM AUTHOR]

Recent research suggests that the retrieval of autobiographical memories among cognitively healthy middle‐aged and older adults is sensitive to the Apolipoprotein E ε4 (APOE4) allele, a genetic marker that increases the risk of Alzheimer's disease (AD) dementia. However, whether the APOE4‐associated alteration in autobiographical memory retrieval encompasses rapid (i.e. direct retrieval) or iterative (i.e. generative retrieval) processes remains unclear. In the present study, 39 APOE4 carriers and 45 non‐carriers (ages 60–80) who scored within normal limits on neuropsychological testing were cued to generate specific autobiographical events. We examined group differences in direct and generative retrieval and correlated direct and generative retrieval rates with performance on neuropsychological tests. Direct retrieval rates were lower in the APOE4 carriers compared to non‐carriers. Episodic memory positively correlated with direct retrieval rates across the sample, though this relationship became non‐significant when factoring in age and sex. There were no significant findings related to successful generative retrieval rates and its efficiency. In summary, compared to non‐carriers, cognitively unimpaired middle‐aged to older adult APOE4 carriers demonstrated greater difficulty, rapidly reconstructing specific autobiographical events without the support of semantic memory, suggesting that early autobiographical memory retrieval processes demonstrate vulnerability to AD‐related risk factors. [ABSTRACT FROM AUTHOR]