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Bailey, N.

Publications and source records attributed to Bailey, N..

At least 19 recordsLinked to original sources
bioRxiv2026

Meditation Depth Enhances the Functional Signal-to-Noise Ratio of the Brain

Across contemplative traditions, depper states of meditation are described as states of heightened clarity, vividness, and stillness of mind, yet what this clarity corresponds to in the brain has remained difficult to specify. The functional signal-to-noise ratio (f-SNR) framework frames mental clarity as a measurable property of neural signals: the degree to which brain activity tracks the causes of sensory signals rather than endogenous, irrelevant, fluctuations. It predicts that deepening meditation should raise f-SNR, expressing sensory events more faithfully in neural signals against ongoing background activity. We tested this prediction across different levels of meditative depth. Twenty-nine experienced Vipassana practitioners meditated while auditory tones were presented, periodically reporting their depth of meditation. f-SNR was quantified from event-related potentials (ERPs) in a fronto-central P3 window and from single-trial decodability of auditory tone-evoked activity against no-tone background EEG. High-depth states were associated with greater ERP signal-to-noise ratio, stronger single-trial signal consistency, and improved decodability of sound tones. These results suggest that meditative depth is expressed in the reproducibility and stimulus-background separability of sensory responses, consistent with deep meditation enhancing the brains functional signal-to-noise ratio by improving the clarity of sensory signals and reducing endogenous noise.

neuroscience↗
bioRxiv2025

Intrinsic RNA hairpin-mediated transcription termination at high temperature in Thermus aquaticus

Transcription termination establishes gene boundaries and limits regulatory interference. In bacteria, intrinsic termination, mediated by an RNA hairpin followed by a polyuridine tract (polyU), is a principal mechanism. Because RNA secondary structures are destabilized at high temperature, whether intrinsic termination functions effectively in thermophiles has been uncertain. We mapped RNA 3' termini genome-wide in the extreme thermophile Thermus aquaticus (Taq) grown at 70 {degrees}C using Term-Seq. Computational analysis identified hairpins upstream of most termini. These hairpins were substantially more thermally stable than those of the mesophile Escherichia coli. RNA 3' ends were also detected within coding regions, consistent with transcriptional pausing or premature termination at spurious hairpins in GC-rich transcripts. In vitro transcription showed that native Taq terminators direct efficient intrinsic termination by Taq RNA polymerase at 70 {degrees}C and require both hairpin and polyU. Termination remained efficient up to 80 {degrees}C. At this temperature, the terminator hairpin RNA is unfolded in solution, indicating that RNA polymerase promotes hairpin formation during transcription. Thus, intrinsic termination operates efficiently in thermophiles. At lower temperatures, expression of the Rho termination factor increased, suggesting that factor-dependent termination may contribute more prominently under cooler growth conditions in Thermus. Significance StatementIntrinsic transcription termination requires formation of an RNA hairpin. Hairpin structures are expected to be unstable at the high temperatures inhabited by thermophilic bacteria. Whether and how hairpin-dependent termination operates under these conditions has remained unknown. Using genome-wide transcripts ends mapping and biochemical approaches, we show that the RNA polymerase of Thermus aquaticus promotes folding of the nascent RNA into a terminator hairpin. This enables efficient termination even at extreme temperatures. Raising temperature favours entropy-driven dissociation of the transcription complex. At lower temperatures, termination appears to increasingly rely on a factor-dependent pathway. Together, these results identify RNA polymerase as an active participant in hairpin-dependent termination and show how temperature may shift the balance between alternative termination mechanisms.

molecular biology↗
bioRxiv2025

Attrition Rates in Mindfulness-Based Interventions for Chronic Pain: A Meta-Analysis

ObjectiveMindfulness-based interventions (MBIs) show promise in managing chronic pain but often require substantial time commitments, leading to high attrition rates and concerns about acceptability. This meta-analysis evaluated attrition rates in MBIs for chronic pain and explored factors contributing to participant withdrawal. MethodsFollowing PRISMA guidelines, 44 studies (45 intervention conditions) were analysed. Data on attrition rates, program characteristics (e.g., delivery method, group vs. individual therapy, session duration), and participant demographics were extracted. Meta-analyses of proportions assessed moderators influencing attrition rates. ResultsThe overall weighted mean attrition rate was 30.1% (95% CI: 24.5% to 37.3%) with substantial heterogeneity (I{superscript 2} = 89.0%). Stricter completion thresholds (defined as the minimum number of sessions required to be considered a programme completer) were associated with higher attrition (p < 0.001, R{superscript 2} = 28.1%), ranging from an 18% attrition rate for low thresholds (completion of [&ge;]3 sessions required to be defined as a completer) to a 49.7% attrition rate for high thresholds ([&ge;]6 sessions). Online delivery showed higher attrition rates (51.0%) compared to in-person delivery (25.6%, p = 0.002, R{superscript 2} = 17.1%). Individually delivered MBIs were also linked to higher attrition compared to group formats ({beta} = 0.216, p = 0.039, R{superscript 2} = 5.5%). ConclusionsAttrition rates for MBIs in chronic pain management vary widely. Higher attrition is associated with stricter completion criteria, online delivery, and individual formats. These findings highlight the need to optimise MBI programme structure to reduce attrition in MBIs for chronic pain management.

pathology↗
bioRxiv2025

The effects of mindfulness on working memory: a systematic review and meta-analysis

ObjectivesMindfulness is a promising health intervention, showing potential effects on cognitive functions like memory. Despite evidence suggesting mindfulness improves working memory, inconsistencies in results and methodologies prevent definitive conclusions. This meta-analysis examines the effects of mindfulness interventions on working memory across clinical and healthy populations, and various age groups. MethodsA systematic search for relevant English and Persian articles was conducted in WOS, Scopus, PsycINFO, and PubMed databases, along with nine meta-analyses up to February 2023. Included studies consisted of randomized controlled trials (RCTs), controlled trials (CTs), and single-group studies. Overall, 29 studies with 2076 participants aged 5-85 years were analyzed. ResultsMindfulness interventions demonstrated a medium effect size on working memory: RCT two-group studies (Hedges g = 0.438, p < 0.001), CT two-group studies (Hedges g = 0.385, p < 0.005), and single-group studies (Hedges g = 0.583, p < 0.001). These findings confirm the effectiveness of mindfulness interventions in improving working memory. ConclusionsMindfulness interventions exhibit promising effects on working memory. However, further primary research, particularly rigorous RCTs, is needed to better understand their impacts on clinical versus healthy populations and across diverse age groups.

neuroscience↗
bioRxiv2024

Brain Segregation and Integration Relate to Word-Finding Abilities in Older and Younger Adults

Previous research has shown that word-finding difficulties in older age are associated with functional and structural brain changes. However, the use of functional brain networks, measured through electroencephalography, to predict word-finding in older and younger adults has not yet been investigated. This study utilised resting-state electroencephalography data (61 channels) from the Leipzig Study for Mind-Body-Emotion Interactions dataset (Babayan et al., 2019) to investigate the relationship between functional brain networks and word-finding ability in healthy younger and older adults. Graph theory-based measures in individualised delta, theta, alpha, and beta bands were computed to assess brain segregation and integration of 53 older (aged 59-77) and 53 younger right-handed adults (aged 20-35). Word-finding ability was quantified as the number of orally produced words during a semantic and letter fluency task. Multiple linear regression revealed that, in older adults, greater functional connectedness in the delta band was associated with lower semantic fluency. Irrespective of age, greater modularity in the alpha band was related to lower semantic fluency. A greater small-world index in the delta band was related to better semantic fluency, irrespective of age. Increased brain integration in the delta band corresponded to greater semantic fluency in older adults. Hence, word-finding ability seems to be related to brain segregation and integration specific to the frequency band, possibly indicating alterations in cognitive control or compensatory shifts to less functionally specific frequency bands. The article further provides a discussion on neural dedifferentiation, hyper-synchronisation, study limitations, and directions for future research.

neuroscience↗
bioRxiv2024

Immunocompetent murine model of Ewing sarcoma reveals role for TGFβ inhibition to enhance immune infiltrates in Ewing tumors during radiation

Ewing sarcoma (ES) is an aggressive cancer diagnosed in adolescents and young adults. The fusion oncoprotein (EWSR1::FLI1) that drives Ewing sarcoma is known to downregulate TGFBR2 expression (part of the TGF{beta} receptor). Because TGFBR2 is downregulated, it was thought that TGF{beta} likely plays an inconsequential role in Ewing biology. However, the expression of TGF{beta} in the Ewing tumor immune microenvironment (TIME) and functional impact of TGF{beta} in the TIME remains largely unknown given the historical lack of immunocompetent preclinical models. Here, we use single-cell RNAseq analysis of human Ewing tumors to show that immune cells, such as NK cells, are the largest source of TGF{beta} production in human Ewing tumors. We develop a humanized (immunocompetent) mouse model of ES and demonstrate distinct TME signatures and metastatic potential in these models as compared to tumors developed in immunodeficient mice. Using this humanized model, we study the effect of TGF{beta} inhibition on the Ewing TME during radiation therapy, a treatment that both enhances TGF{beta} activation and is used to treat aggressive ES. Utilizing a trivalent ligand TGF{beta} TRAP to inhibit TGF{beta}, we demonstrate that in combination with radiation, TGF{beta} inhibition both increases ES immune cell infiltration and decreases lung metastatic burden in vivo. The culmination of these data demonstrates the value of humanized models to address immunobiologic preclinical questions in Ewing sarcoma and suggests TGF{beta} inhibition as a promising intervention during radiation therapy to promote metastatic tumor control.

cancer biology↗
bioRxiv2023

TMS-EEG shows mindfulness meditation is associated with an altered excitation/inhibition balance in the dorsolateral prefrontal cortex

ObjectiveMindfulness meditation is associated with functional brain changes in regions subserving higher order cognitive processes such as attention. However, no research to date has causally probed these areas in meditators using combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG). This study aimed to investigate whether cortical reactivity to TMS differs in a community sample of experienced mindfulness meditators when compared to matched controls MethodsTMS was applied to the left and right dorsolateral prefrontal cortices (DLPFC) of 19 controls and 15 meditators while brain responses were measured using EEG. TMS-evoked potentials (P60 and N100) were analysed, and exploratory analyses using the whole EEG scalp field were performed to test whether TMS-evoked global neural response strength or the distribution of neural activity differed between groups. ResultsMeditators were found to have statistically larger P60/N100 ratios in response to left and right hemisphere DLPFC stimulation compared to controls (pFDR = 0.004, BF10 > 39). No differences were observed in P60 or N100 amplitudes when examined in isolation. We also found preliminary evidence for differences in the distribution of neural activity 269-332ms post stimulation. ConclusionThese findings demonstrate differences in cortical reactivity to TMS in meditators. Differences in the distribution of neural activity approximately 300ms following stimulation suggest differences in cortico-subcortical reverberation in meditators that may be indicative of greater inhibitory activity in frontal regions. This research contributes to our current understanding of the neurophysiology of mindfulness and highlights opportunities for further exploration into the mechanisms underpinning the benefits of mindfulness meditation.

neuroscience↗
bioRxiv2023

A chromosome-scale assembly for dAnjou pear

Cultivated pear consists of several Pyrus species with P. communis (European pear) representing a large fraction of worldwide production. As a relatively recently domesticated crop and perennial tree, pear can benefit from genome-assisted breeding. Additionally, comparative genomics within Rosaceae promises greater understanding of evolution within this economically important family. Here, we generate a fully-phased chromosome-scale genome assembly of P. communis cv. dAnjou. Using PacBio HiFi and Dovetail Omni-C reads, the genome is resolved into the expected 17 chromosomes, with each haplotype totalling nearly 540 Megabases and a contig N50 of nearly 14 Mb. Both haplotypes are highly syntenic to each other, and to the Malus domestica Honeycrisp apple genome. Nearly 45,000 genes were annotated in each haplotype, over 90% of which have direct RNA-seq expression evidence. We detect signatures of the known whole-genome duplication shared between apple and pear, and we estimate 57% of dAnjou genes are retained in duplicate derived from this event. This genome highlights the value of generating phased diploid assemblies for recovering the full allelic complement in highly heterozygous crop species.

genomics↗
bioRxiv2023

Experienced Meditators Show Multifaceted Attention-Related Differences in Neural Activity

ObjectivesMindfulness meditation (MM) is suggested to improve attention. Research has explored this using the attentional-blink (AB) task, where stimuli are rapidly presented, and a second target stimulus (T2) is often missed if presented [~]300ms after an initial target stimulus (T1). This research showed improved task-accuracy and altered neural activity after an intensive 3-month MM retreat. We tested whether these results replicated in a community sample of typical meditators. MethodsThirty-one mindfulness meditators and 30 non-meditators completed an AB task while electroencephalography (EEG) was recorded. Between-group comparisons were made for task-accuracy, event-related potential activity (posterior-N2 and P3b), theta and alpha oscillatory phase synchronisation to stimuli presentation, and alpha-power. Primary aims examined effects within time windows reported by previous research. Additional exploratory aims assessed effects across broader time windows. ResultsNo differences were detected in task-accuracy or neural activity within our primary hypotheses. However, exploratory analyses showed posterior-N2 and theta phase synchronisation effects indicating meditators prioritised attending to T2 stimuli (p < 0.01). Meditators also showed more alpha-phase synchronisation, and lower alpha-power when processing T2 stimuli (p < 0.025). ConclusionsOur results showed multiple differences in neural activity that suggested enhanced attention in meditators. The neural activity patterns in meditators aligned with theoretical perspectives on activity associated with enhanced cognitive performance. These include enhanced alpha gating mechanisms, increased oscillatory synchronisation to stimuli, and more equal allocation of neural activity across stimuli. However, meditators did not show higher task-accuracy, nor did effects align with our primary hypotheses or previous research. PreregistrationThis study was not preregistered.

neuroscience↗
bioRxiv2022

Meditators probably show increased behaviour-monitoring related neural activity

ObjectivesMindfulness meditation is associated with better attention function. Performance monitoring and error-processing are important aspects of attention. We investigated whether experienced meditators showed different neural activity related to performance monitoring and error-processing. Previous research has produced inconsistent results. This study used more rigorous analyses and a larger sample to resolve the inconsistencies. MethodsWe used electroencephalography (EEG) to measure the error-related negativity (ERN) and error positivity (Pe) following correct and incorrect responses to a Go/Nogo task from 27 experienced meditators and 27 non-meditators. ResultsNo differences were found in the ERN (all p > 0.05). Meditators showed larger global field potentials (GFP) in the Pe after both correct responses and errors, indicating stronger neural responses (p = 0.0190, FDR-p = 0.152, np2 = 0.0951, BFincl = 2.691). This effect did not pass multiple comparison controls. However, single electrode analysis of the Pe did pass multiple comparison controls (p = 0.002, FDR-p = 0.016, np2 = 0.133, BFincl = 220.659). Meditators also showed a significantly larger Pe GFP for errors only, which would have passed multiple comparison controls, but was not a primary analysis (p = 0.0028, np2 = 0.1493, BF10 = 9.999). ConclusionsMeditation may strengthen neural responses related to performance monitoring (measured by the Pe), but not specifically to error monitoring (although measurements of the Pe after errors may be more sensitive to group differences). However, only the single electrode analysis passed multiple comparison controls, while analysis including all electrodes did not, so this conclusion remains tentative.

neuroscience↗
bioRxiv2022

Introducing RELAX (the Reduction of Electroencephalographic Artifacts): A fully automated pre-processing pipeline for cleaning EEG data - Part 1: Algorithm and Application to Oscillations

Electroencephalographic (EEG) data is typically contaminated with non-neural artifacts which can confound the results of experiments. Artifact cleaning approaches are available, but often require time-consuming manual input and significant expertise. Advancements in artifact cleaning often only address a single artifact, are only compared against a small selection of pre-existing methods, and seldom assess whether a proposed advancement improves experimental outcomes. To address these issues, we developed RELAX (the Reduction of Electroencephalographic Artifacts), an automated EEG cleaning pipeline implemented within EEGLAB that reduces all artifact types. RELAX cleans continuous data using Multiple Wiener filtering [MWF] and/or wavelet enhanced independent component analysis [wICA] applied to artifacts identified by ICLabel [wICA_ICLabel]). Several versions of RELAX were tested using three datasets containing a mix of cognitive and resting recordings (N = 213, 60 and 23 respectively). RELAX was compared against six commonly used EEG cleaning approaches across a wide range of artifact cleaning quality metrics, including signal-to-error and artifact-to-residue ratios, measures of remaining blink and muscle activity, and the amount of variance explained by experimental manipulations after cleaning. RELAX with MWF and wICA_ICLabel showed amongst the best performance for cleaning blink and muscle artifacts while still preserving neural signal. RELAX with wICA_ICLabel (and no MWF) may perform better at detecting the effect of experimental manipulations on alpha oscillations in working memory tasks. The pipeline is easy to implement in MATLAB and freely available on GitHub. Given its high cleaning performance, objectivity, and ease of use, we recommend RELAX for data cleaning across EEG studies.

neuroscience↗
bioRxiv2022

Introducing RELAX (the Reduction of Electroencephalographic Artifacts): A fully automated pre-processing pipeline for cleaning EEG data - Part 2: Application to Event-Related Potentials

Electroencephalography (EEG) is commonly used to examine neural activity time-locked to the presentation of a stimulus, referred to as an Event-Related Potential (ERP). However, EEG is also influenced by non-neural artifacts, which can confound ERP comparisons. Artifact cleaning can reduce artifacts, but often requires time-consuming manual decisions. Most automated cleaning methods require frequencies <1Hz to be filtered out of the data, so are not recommended for ERPs (which often contain <1Hz frequencies). In our companion article, we introduced RELAX (the Reduction of Electroencephalographic Artifacts), an automated and modular cleaning pipeline that reduces artifacts with Multiple Wiener Filtering (MWF) and/or wavelet enhanced independent component analysis (wICA) applied to artifact components detected with ICLabel (wICA_ICLabel) (Bailey et al., 2022). To evaluate the suitability of RELAX for data cleaning prior to ERP analysis, multiple versions of RELAX were compared to four commonly used EEG cleaning pipelines. Cleaning performance was compared across a range of artifact cleaning metrics and in the amount of variance in ERPs explained by different conditions in a Go-Nogo task. RELAX with MWF and wICA_ICLabel cleaned the data the most effectively and produced amongst the most dependable ERP estimates. RELAX with wICA_ICLabel only or MWF_only may detect experimental effects better for some ERP measures. Importantly, RELAX can high-pass filter data at 0.25Hz, so is applicable to analyses involving ERPs. The pipeline is easy to implement via EEGLAB in MATLAB and is freely available on GitHub. Given its performance, objectivity, and ease of use, we recommend RELAX for EEG data cleaning. The MATLAB code, the supplementary materials, and a simple instruction manual explaining how to implement the RELAX pipeline can be downloaded from https://github.com/NeilwBailey/RELAX/releases. A condition of use of the pipeline is that the version of the pipeline used is referred to as RELAX_[pipeline], for example "RELAX_MWF_wICA" or "RELAX_wICA_ICLabel", and that the current paper be cited, as well as the dependencies used. These dependencies are likely to include: EEGLAB (Delorme & Makeig, 2004), fieldtrip (Oostenveld et al., 2011), the MWF toolbox (Somers et al., 2019), fastICA (Hyvarinen, 1999), wICA (Castellanos & Makarov, 2006), ICLabel (Pion-Tonachini et al., 2019), and PREP (Bigdely-Shamlo et al., 2015) See our companion article for the application of RELAX to the study of oscillatory power (Bailey et al., 2022).

neuroscience↗
bioRxiv2020

Tyrosine phosphorylation of ACLY regulates lipid metabolism and oncogenesis in ALK positive Anaplastic Large Cell Lymphoma

A fundamental requirement for growth of rapidly proliferating cells is metabolic adaptation to promote synthesis of biomass1. ATP citrate lyase (ACLY) is a critical enzyme responsible for synthesis of cytosolic acetyl-CoA, the key building component for de novo fatty acid synthesis and links vital pathways such as carbohydrate and lipid metabolism2. The mechanisms of ACLY regulation are not completely understood and the regulation of ACLY function by tyrosine phosphorylation is unknown. Here we show using mass-spectrometry-driven phosphoproteomics and metabolomics that ACLY is phosphorylated and functionally regulated at an evolutionary conserved residue, Y682. Physiologic signals promoting rapid cell growth such as epidermal growth factor stimulation in epithelial cells and T-cell receptor activation in primary human T-cells result in rapid phosphorylation of ACLY at Y682. In vitro kinase assays demonstrate that Y682 is directly phosphorylated by multiple tyrosine kinases, including ALK, ROS1, SRC, JAK2 and LTK. Oncogenically activating structural alterations such as gene-fusions, amplification or point mutations of ALK tyrosine kinase result in constitutive phosphorylation of ACLY in diverse forms of primary human cancer such as lung cancer, anaplastic large cell lymphoma (ALCL) and neuroblastoma. Expression of a phosphorylation-defective ACLY-Y682F mutant in NPM-ALK+ ALCL decreases ACLY activity and attenuates lipid synthesis. Metabolomic analyses reveal that ACLY-Y682F expression results in increased {beta}-oxidation of 13C-oleic acid-labeled fatty acid with increased labeling of +2-citrate (p<0.01) and +18-oleyol carnitine (p<0.001). Similarly, oxygen consumption rate (OCR) is significantly increased in cells expressing ACLY-Y682F (p<0.001). Moreover, expression of ACLY-Y682F dramatically decreases cell proliferation, impairs clonogenicity and abrogates tumor growth in vivo. Our results reveal a novel mechanism for direct ACLY regulation that is subverted by multiple oncogenically-activated tyrosine kinases in diverse human cancers. These findings have significant implications for novel therapies targeting ACLY in cancer and metabolism.

cancer biology↗
bioRxiv2019

Mindfulness meditators show enhanced working memory performance concurrent with different brain region engagement patterns during recall

Mindfulness meditation has been shown to improve working memory (WM). However, the altered brain activity underpinning these improvements is underexplored. In non-meditating individuals, modulation of theta and alpha oscillations and 1/f aperiodic activity during WM has been found to be related to WM performance. Resting theta and alpha oscillations have been found to differ in meditators, but WM related oscillation changes and 1/f aperiodic activity have not yet been examined. Additionally, WM event-related-potentials (ERPs) are modulated by attention, which is also enhanced by meditation, so these neural measures are candidates for exploring neural activity underpinning WM improvement in meditators. We recorded EEG from 29 controls and 29 meditators during a modified Sternberg WM task and compared theta, alpha, and 1/f aperiodic activity during the WM delay, and ERPs time-locked to the WM probe. Meditators responded more accurately (p = 0.008, Cohens d = 0.688). Meditators also showed different ERP distributions with earlier left-temporal activation and more frontal distribution of activity (FDR-p = 0.0186, {eta}2 = 0.0903), as well as a reduction in overall neural response strength (FDR-p = 0.0098, {eta}2 = 0.1251). While a higher proportion of meditators showed theta oscillations during the WM delay, no other differences in theta, alpha or 1/f aperiodic activity were present. These results suggest that increased WM performance in meditators might not be the result of higher amplitudes of typical WM activity, but instead due to an alternative neural strategy during WM decision making, which may allow more accurate responses with less neural activation.\n\nHighlights- Long term mindfulness meditators showed improved working memory (WM) accuracy\n- This was concurrent with earlier left temporal activation following probe stimuli\n- As well as a more frontal distribution and reduced overall neural response strength\n- No oscillation differences were present in the working memory delay period\n- Improved WM from altered neural strategy rather than increased neural activity

neuroscience↗
bioRxiv2018

Silent crickets reveal the genomic footprint of recent adaptive trait loss

Secondary trait loss is widespread and has profound consequences, from generating diversity to driving adaptation. Sexual trait loss is particularly common1. Its genomic impact is challenging to reconstruct because most reversals occurred in the distant evolutionary past and must be inferred indirectly2, and questions remain about the extent of disruption caused by pleiotropy, altered gene expression and loss of homeostasis3. We tested the genomic signature of recent sexual signal loss in Hawaiian field crickets, Teleogryllus oceanicus. Song loss is controlled by a sex-linked Mendelian locus, flatwing, which feminises male wings by erasing sound-producing veins. This variant spread rapidly under pressure from an eavesdropping parasitoid fly. We sequenced, assembled and annotated the T. oceanicus genome, produced a high-density linkage map, and localised flatwing on the X chromosome. We characterised pleiotropic effects of flatwing, including changes in embryonic gene expression and alteration of another sexual signal, chemical pheromones. Song loss is associated with pleiotropy, hitchhiking and genome-wide regulatory disruption which feminises flatwing male pheromones. The footprint of recent adaptive trait loss illustrates R. A. Fishers influential prediction that variants with large mutational effect sizes can invade genomes during the earliest stages of adaptation to extreme pressures, despite having severely disruptive genomic consequences.

evolutionary biology↗
bioRxiv2018

Mindfulness meditators do not show differences in electrophysiological measures of error processing

Mindfulness meditation may improve attention and self-regulation. One component of attention and self-regulation that may allow these improvements is performance monitoring. Neural correlates of performance monitoring can be objectively measured with electroencephalogram (EEG) via the error related negativity (ERN) and error positivity (Pe). Previous research assessing the ERN and Pe in meditators has resulted in inconsistent findings; some have reported alteration in peak amplitudes from both very brief meditation practice and long-term meditation practice, while others have failed to provide evidence for differences in the ERN or Pe. However, recently developed EEG analysis techniques allow for more rigorous analyses than have been used in past investigations. The current study measured the ERN and Pe, as well as post-error alpha suppression, during a Go/Nogo task, and emotional and colour Stroop tasks. The measures were compared between 22 experienced meditators (mean of 8 years of practice) and 20 healthy controls. The results suggested no differences in the ERN, Pe, or post-error alpha suppression (all p > 0.05), even when varying multiple analysis parameters. The study showed equivalent statistical power to previous research, and > 85% power to detect medium effect sizes present in previous research. Bayes Factor analysis indicated the null hypotheses were > 3.5 more likely than any of the alternative hypotheses for the ERN or Pe. These results suggest that meditation may not alter neural activity related to error processing, despite prior research suggesting that it does.

neuroscience↗
bioRxiv2018

Mindfulness meditators show altered distributions of early and late neural activity markers of attention in a response inhibition task

Attention is a vital executive function, since other executive functions are largely dependent on it. Mindfulness meditation has been shown to enhance attention. However, the components of attention altered by meditation and the related neural activities are underexplored. In particular, the contributions of inhibitory processes and sustained attention are not well understood. Additionally, it is not clear whether improvements in attention are related to increases in the strength of typically activated brain areas, or the recruitment of additional or alternative brain areas. To address these points, 34 meditators were compared to 28 age and gender matched controls during electroencephalography (EEG) recordings of neural activity during a Go/Nogo response inhibition task. This task generates a P3 event related potential, which is related to response inhibition processes in Nogo trials, and attention processes across both trial types. Compared with controls, meditators were more accurate at responding to Go and Nogo trials. Meditators showed a more frontally distributed P3 to both Go and Nogo trials, suggesting more frontal involvement in sustained attention rather than activity specific to response inhibition. Unexpectedly, meditators also showed increased positivity over the right parietal cortex prior to visual information reaching the occipital cortex. Both results were positively related to increased accuracy across both groups. The results suggest that meditators have an increased capacity to modulate a range of neural processes in order to meet task requirements, including higher order processes, and sensory anticipation processes. This increased capacity may underlie the improved attentional function observed in mindfulness meditators.

neuroscience↗