The Mindful Brain: A Systematic Review of the Neural Correlates of Trait Mindfulness

The paper addresses whether self-reported trait mindfulness has reliable neural correlates across neuroimaging modalities and psychological mechanisms. It situates trait mindfulness within contemplative traditions and modern clinical practice, reviews common measures (MAAS, FFMQ, others), and notes debates about their validity and incremental value over broader personality traits. The objective is to systematically evaluate brain structure and function associated with trait mindfulness across structural MRI, resting-state and task-based fMRI, and EEG, mapping task-based findings to core mechanisms of self-regulation (emotion regulation, self-awareness, attention, and body awareness). Understanding these correlates could clarify mechanisms underlying mindfulness-related well-being and inform clinical applications.

Prior work links higher trait mindfulness to better psychological well-being and cognitive performance, and increases after mindfulness training, but questions the validity of trait scales (e.g., differences between meditators and nonmeditators, overlap with Big Five, and potential jangle fallacy). Theoretical models parse mindfulness into mechanisms like attention regulation, emotion regulation, decentering, and body awareness. Neuroscience literature implicates networks such as the DMN, FPN, and SN in attention and self-related processes, and limbic-prefrontal circuits in emotion regulation. Despite numerous studies correlating trait mindfulness with neural measures, no prior systematic review synthesized cross-modality evidence, motivating this work.

The authors conducted an initial scoping search (Nov 2022) across Google Scholar and ProQuest, identifying 50 studies. A subsequent systematic PubMed search using "trait mindfulness AND neuro*" yielded 370 records. Inclusion criteria required a valid trait mindfulness measure (e.g., MAAS, FFMQ, FMI, PMS, KIMS, CAMS-R, CAMM, AAMS, SMQ, CHIME) and a valid neuroimaging measure (structural MRI, DWI/DTI, resting-state fMRI, task-based fMRI, or EEG). PET studies were excluded due to insufficient evidence for synthesis (n=2). Dissertations and posters were included to mitigate publication bias. Screening and eligibility assessment followed PRISMA guidelines; 18 studies were retained from PubMed and combined with prior searches for a total of 68 studies. Studies were categorized by modality: 9 structural imaging, 17 resting-state fMRI, 19 task-based fMRI, and 23 EEG. Task-based studies were further mapped to mechanisms (emotion regulation, self-awareness, attention, body awareness; multiple mappings allowed). For structural and resting-state studies, the review emphasized findings replicated across three or more studies (including nulls). For task-based studies, findings were summarized per mechanism. Sample size trends, preregistration rates, and measure reliability were noted.

- Corpus of evidence: 68 studies identified; modalities included 9 structural MRI/DWI, 17 resting-state fMRI, 19 task-based fMRI, and 23 EEG. Most samples were small (n < 50), with task-based fMRI and EEG sample sizes increasing over time; structural MRI sample sizes decreased over time. - Structural MRI: Associations between higher trait mindfulness and greater cortical thickness in frontal regions and insular cortex; mixed findings for amygdala volume (increases or decreases depending on scale/study). DMN-related structures showed associations (e.g., precuneus volume positively with MAAS; PCC volume negatively with MAAS; network-based associations including hippocampus and cerebellum). Attentional control regions (dorsolateral PFC, ACC, medial frontal cortex) showed positive associations with mindfulness. - Resting-state fMRI (static FC): Convergent evidence for decreased within-DMN connectivity with higher trait mindfulness across multiple studies; between-network connectivity (DMN–SN, DMN–FPN) showed inconsistent directions across studies. - Resting-state fMRI (dynamic FC): Mixed results regarding dwell time in states with DMN anticorrelated to FPN/SN; some studies found greater dwell time with higher mindfulness, others found the opposite or no relation. - Resting-state other metrics: ReHo increases in insula, orbitofrontal cortex, parahippocampal gyrus, and decreases in inferior frontal gyrus with higher MAAS; graph-theoretic and ALFF findings implicated insula organization (more locally connected, less globally connected) in more mindful individuals. - Task-based fMRI (emotion regulation): Consistent attenuation of amygdala responses to emotional stimuli with higher trait mindfulness (especially Nonreactivity facet); some studies show increased PFC engagement during explicit regulation (e.g., affect labeling). Overall pattern suggests reduced bottom-up reactivity and possible enhanced top-down control, though the latter is less consistent. - Task-based fMRI (attention): Higher mindfulness associated with greater activation/connectivity in attention networks (FPN, dorsal and ventral attention networks) during focused attention tasks; one adolescent study found reduced right VLPFC activation during working memory with higher mindfulness. - Task-based fMRI (body awareness, self-awareness): Sparse and heterogeneous; one study showed inverse insula activation with interoceptive attention correlating with greater mindfulness; a self-referential task found DMPFC differences linked to Nonreactivity. - EEG (emotion regulation ERPs): Inconsistent findings for LPP modulation by trait mindfulness (reports of decreases, increases, and null effects); early components (N100/N200/P300) showed mixed relations depending on scale/subfacet; large study found no relation between mindfulness and error-related negativity/positivity. - EEG (attention/other): Mixed results across tasks and resting state; some microstate studies linked higher mindfulness (particularly Nonreactivity) to reduced time in salience-related microstates; power spectral findings varied and were confounded by anxiety groupings in some studies. - Convergence with training/expert meditators: Findings align with intervention/LTM literature showing increased cortical thickness (prefrontal, insula), decreased DMN activity/connectivity during meditation, and reduced amygdala reactivity after training. - Overall: Most consistent neural correlates of higher trait mindfulness are decreased amygdala reactivity, increased frontal/insular cortical thickness, and decreased within-DMN connectivity. EEG correlates and between-network rs-fMRI metrics remain inconclusive.

The review’s multimodal synthesis indicates that trait mindfulness relates to reduced bottom-up emotional reactivity (lower amygdala responses), potential enhancement of top-down regulatory control (select PFC findings), structural substrate differences in frontal and insular regions, and reduced intrinsic coupling within the DMN, which may reflect a shift from narrative to experiential self-processing and reduced mind-wandering. These patterns broadly align with neural changes observed following mindfulness interventions and in long-term meditators, supporting the construct validity of certain aspects of trait mindfulness. However, inconsistent EEG findings and mixed results for dynamic and between-network connectivity underscore measurement and reliability challenges, potential heterogeneity in trait operationalizations (e.g., MAAS vs. FFMQ facets), and context-dependency (e.g., induction effects). The findings suggest that focusing on specific mechanisms and subfacets may yield clearer brain–behavior relationships, and that insula and DMN measures may be promising targets for future biomarker work related to mental health outcomes.

This first systematic review of neural correlates of trait mindfulness identifies convergent associations across modalities: decreased amygdala reactivity to emotion, increased frontal and insular cortical thickness, and reduced within-DMN connectivity. These converge with effects observed after mindfulness training and in expert meditators, suggesting shared mechanisms. The review highlights substantial gaps and inconsistencies—especially in EEG and between-network rs-fMRI—and recommends future research with larger, preregistered samples; data-driven, multivariate, and reliability-aware analyses; item-level and facet-specific approaches to self-report; and integration across modalities. It calls for targeted studies of self-awareness and body awareness with appropriate tasks and measures, and for moving beyond monolithic trait definitions toward developmental, mechanism-focused models of mindfulness and its brain bases.

- Search breadth may have missed relevant studies; many included studies reported mindfulness–brain associations as secondary/exploratory, risking selective reporting. - High heterogeneity across samples (age, meditation experience, clinical status), with potential differences in how scales are interpreted by subgroups. - Predominantly cross-sectional, correlational designs limit causal inference; structural–functional links were not directly tested within individuals. - Risk of reverse inference in interpreting structural and functional differences; structural–functional relationships can be nonintuitive. - Small sample sizes typical; robust brain–behavior correlations may require very large samples. Preregistration was rare. - Unclear incremental validity over Big Five and related constructs; neural correlates identified may not be unique to mindfulness. - ERP/EEG measures show reliability and analytic flexibility issues, complicating consistent interpretation.