Meditation and the brain - Neuronal correlates of mindfulness as assessed with near-infrared spectroscopy

Effect of Mindfulness Training on Skill Performance in Simulator-Based Knee Arthroscopy Training for Novice Residents-A Randomized Controlled Study

OBJECTIVES

Negative emotions affect not only the physical health of residents but also the performance of surgical skills. Mindfulness training has been shown to be effective in improving mood. However, few studies have explored its effect on surgical skill performance. We aimed to investigate the effect of mindfulness training on knee arthroscopy skill performance.

DESIGN

We recruited 30 participants for knee arthroscopy skills training (Tasks 1-7) on a simulator, after which a pretest (Tasks 8 and 9) was conducted to test their skill performance and psychological states (including mindfulness state, anxiety, stress, and depression). Then, they were randomly assigned into 2 groups: the intervention group underwent 2 weeks of mindfulness training while the control group received no intervention. All participants were asked to retrain their skills 1 week after completing the initial arthroscopy skill training. After the 2-week mindfulness training intervention, a post-test was performed to detect the difference in skill performance and psychological states between 2 groups. We used the fNIRS device to record prefrontal cortex activation during the post-test.

SETTING

The study was carried out at the Zhujiang Hospital of Southern Medical University.

PARTICIPANTS

30 novice orthopedic residents.

RESULTS

A total of 30 residents completed all the study programs. We did not observe differences in arthroscopy skill performance at pretest. Compared with the control group, the intervention group showed significant improvement in total score of Task 8 (p = 0.034) and 9 (p = 0.002), as well as significant relief in anxiety (p = 0.037) and stress (p = 0.027) symptoms but no improvement in depression (p = 0.828). No statistical difference in 2 groups was observed on the activation of the left prefrontal cortex (p = 0.68).

CONCLUSIONS

Two weeks of mindfulness training can improve arthroscopy skill performance while alleviating anxiety and reducing stress in novice residents. Mindfulness training may be an effective adjunct to surgical skill training.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, Number: ChiCTR2200058144.

Neural correlates of breath work, mental imagery of yoga postures, and meditation in yoga practitioners: a functional near-infrared spectroscopy study

Objective

Previous research has shown numerous health benefits of yoga, a multicomponent physical and mental activity. The three important aspects of both traditional and modern yoga are breath work, postures, and meditation. However, the neural mechanisms associated with these three aspects of yoga remain largely unknown. The present study investigated the neural underpinnings associated with each of these three yoga components in long- and short-term yoga practitioners to clarify the neural advantages of yoga experience, aiming to provide a more comprehensive understanding of yoga's health-promoting effects.

Methods

Participants were 40 Chinese women, 20 with a long-term yoga practice and 20 with a short-term yoga practice. Functional near-infrared spectroscopy was conducted while participants performed abdominal breathing, mental imagery of yoga postures, and mindfulness meditation. The oxygenated hemoglobin concentrations activated in the brain during these three tasks were used to assess the neural responses to the different aspects of yoga practice. The self-reported mastery of each yoga posture was used to assess the advantages of practicing yoga postures.

Results

Blood oxygen levels in the dorsolateral prefrontal cortex during breath work were significantly higher in long-term yoga practitioners than in short-term yoga practitioners. In the mental imagery of yoga postures task, self-reported data showed that long-term yoga practitioners had better mastery than short-term practitioners. Long-term yoga practitioners demonstrated lower activation in the ventrolateral prefrontal cortex, with lower blood oxygen levels associated with performing this task, than short-term yoga practitioners. In the mindfulness meditation task, blood oxygen levels in the orbitofrontal cortex and the ventrolateral prefrontal cortex were significantly higher in long-term yoga practitioners than in short-term yoga practitioners.

Conclusion

The three core yoga components, namely, yogic breathing, postures, and meditation, showed differences and similarities in the activation levels of the prefrontal cortex. Long-term practice of each component led to the neural benefits of efficient activation in the prefrontal cortex, especially in the dorsolateral prefrontal cortex, orbitofrontal cortex, and ventrolateral prefrontal cortex.

How Does Meditation Affect the Default Mode Network: A Systematic Review

This article provides a systematic review of studies evaluating the effect of meditation on the Default Mode Network (DMN). The review was conducted according to PRISMA guidelines. A literature search of PubMed, Scopus, and Embase was conducted up to June 2020. Search terms included default mode network or DMN and meditation.A total of 306 articles were identified, of which 16 controlled trials with a total of 853 experienced (in Mindfulness, Samatha, Raja Yoga, Transcendental Meditation, Vipassana, Insight meditation Theravada tradition) and non-experienced mediators were finally included in this systematic review. The results showed that meditative interventions affect the operation of DMN and there are differences in functional connectivity between networks. Further research should be undertaken to establish meditation as an effective intervention strategy for well-being.

A Prospective Observational Pilot Study on the Effects of the Activity-Based Stress Release Program on the Mental State and Autonomic Nervous System in Psychiatric Patients

BACKGROUND

In our pilot study, we investigated the psychological (well-being and personal coping strategies) and physiological (assessed by heart rate variability (HRV)) effects of the newly developed activity-based stress release (ABSR) program for people with depressive disorders, also in combination with burnout symptoms and/or anxiety disorders.

METHODS

A single-arm prospective observational study was carried out. Twenty participants diagnosed with depression and burnout or anxiety disorders were invited to participate in the 8-week ABSR program. All participants filled in two questionnaires (the multidimensional mental state questionnaire and the Ehrenfeld inventory on coping style) before, directly after and 2 months after the 8-week ABSR program. In addition, all participants were offered a 24-hour Holter ECG measurement before, directly after and 2 months after the 8-week ABSR program to measure HRV.

RESULTS

Calmness and serenity showed a statistically significant improvement after the 8-week ABSR program. However, complete questionnaire sets were not available from all of the participants. In the four individuals who had agreed to a 24-hour Holter ECG, the overall HRV and parasympathetic activity increased.

CONCLUSIONS

The ABSR program is an encouraging novel therapeutic approach: A significant improvement in calmness and serenity was observed after ABSR. A larger and controlled trial of this treatment option in depression and burnout is recommended. It should be further investigated how ABSR affects task-evoked and resting brain activity, and what effects it has on the cardiovascular system in general (better blood flow and normalization of activity are to be expected).

S, Ganesh P, Vasu HV. Job Search during COVID-19: How Online Mindfulness Intervention helped to Reduce Stress and Enhance the Self-esteem of the Job Seeker

Background: Immediately after graduation from university, college students need to make significant decisions about starting their careers or pursuing higher studies. They are also pressured to meet the expectations and demands of self, others, and the environment. Owing to the impact of the COVID-19 pandemic, the aforementioned challenging decisions may become hazardous stressors for college students. Hence, the researchers intended to assist and assess the college students involved in student placements. The research goal was to investigate the impact of mindfulness-based intervention (MBI) on the stress and self-esteem of college students involved in student placements.  Methods: One hundred college students participating in the campus placements were selected using purposive sampling from Amrita Vishwa Vidyapeetham University in Coimbatore, India. For evaluation purposes, college students were administered the perceived stress, Rosenberg self-esteem, and Kuppuswamy socio-economic scales. Seventy-five college students were selected for the MBI process and were administered with a pre-intervention and post-intervention without a control group research design. Results: Statistical analysis including analysis of variance (ANOVA) and the Bonferroni post hoc test showed a significant increase in self-esteem and a decrease in the stress of the college students involved in placements. Conclusions: Thus, the researchers recommend that policymakers create awareness, include MBI in the curriculum, and allocate funds for training ventures in educational institutions to assist college students in their challenging life journeys.

Brain Functional Connectivity in the Resting State and the Exercise State in Elite Tai Chi Chuan Athletes: An fNIRS Study

This study aimed to reveal the characteristics of multi-circuit brain synergy between elite tai chi chuan athletes in resting and exercise states and to provide neuroimaging evidence of improvements in brain function by motor skill training. Functional near-infrared spectroscopy (fNIRS) was used to compare the brain activity of professional tai chi chuan athletes (expert group) and beginners (novice group) in resting and exercise states, and to assess functional connectivity (FC) between the prefrontal lobe and the sensorimotor zone. In the resting state, the FC between the left prefrontal lobe and the right sensorimotor area in the expert group was significantly lower than that in the novice group (P < 0.05). In the exercise state, the patterns of FC between the left prefrontal lobe and right sensorimotor area, the right prefrontal lobe and left sensorimotor area, and the left and right sensorimotor areas in the expert group were significantly lower than that in the novice group (P < 0.05). From the resting state to the locomotor state, the expert group experienced a greater absolute value of functional connection increment between the left prefrontal cortex and right sensorimotor area, and between the left sensorimotor area and right sensorimotor area (P < 0.05). This was positively correlated with the self-evaluation results of motor performance behavior. Under sports conditions, professional athletes’ multi-circuit brain FC strength is significantly reduced, and their elite motor skill performance supports the neural efficiency hypothesis. This may be related to the high adaptation of the brain to specific tasks and the improvement of the integration of somatic perception processing and motor function.

Investigation of functional near-infrared spectroscopy signal quality and development of the hemodynamic phase correlation signal

Significance: There is a longstanding recommendation within the field of fNIRS to use oxygenated (HbO 2 ) and deoxygenated (HHb) hemoglobin when analyzing and interpreting results. Despite this, many fNIRS studies do focus onHbO 2 only. Previous work has shown thatHbO 2 on its own is susceptible to systemic interference and results may mostly reflect that rather than functional activation. Studies using bothHbO 2 and HHb to draw their conclusions do so with varying methods and can lead to discrepancies between studies. The combination ofHbO 2 and HHb has been recommended as a method to utilize both signals in analysis. Aim: We present the development of the hemodynamic phase correlation (HPC) signal to combineHbO 2 and HHb as recommended to utilize both signals in the analysis. We use synthetic and experimental data to evaluate how the HPC and current signals used for fNIRS analysis compare. Approach: About 18 synthetic datasets were formed using resting-state fNIRS data acquired from 16 channels over the frontal lobe. To simulate fNIRS data for a block-design task, we superimposed a synthetic task-related hemodynamic response to the resting state data. This data was used to develop an HPC-general linear model (GLM) framework. Experiments were conducted to investigate the performance of each signal at different SNR and to investigate the effect of false positives on the data. Performance was based on each signal's mean T -value across channels. Experimental data recorded from 128 participants across 134 channels during a finger-tapping task were used to investigate the performance of multiple signals [HbO 2 , HHb, HbT, HbD, correlation-based signal improvement (CBSI), and HPC] on real data. Signal performance was evaluated on its ability to localize activation to a specific region of interest. Results: Results from varying the SNR show that the HPC signal has the highest performance for high SNRs. The CBSI performed the best for medium-low SNR. The next analysis evaluated how false positives affect the signals. The analyses evaluating the effect of false positives showed that the HPC and CBSI signals reflect the effect of false positives onHbO 2 and HHb. The analysis of real experimental data revealed that the HPC and HHb signals provide localization to the primary motor cortex with the highest accuracy. Conclusions: We developed a new hemodynamic signal (HPC) with the potential to overcome the current limitations of usingHbO 2 and HHb separately. Our results suggest that the HPC signal provides comparable accuracy to HHb to localize functional activation while at the same time being more robust against false positives.

Application of Near-Infrared Spectroscopy for Evidence-Based Psychotherapy

This perspective article discusses the importance of evidence-based psychotherapy and highlights the usefulness of near-infrared spectroscopy (NIRS) in assessing the effects of psychotherapeutic interventions as a future direction of clinical psychology. NIRS is a safe and non-invasive neuroimaging technique that can be implemented in a clinical setting to measure brain activity via a simple procedure. This article discusses the possible benefits and challenges of applying NIRS for this purpose, and the available methodology based on previous studies that used NIRS to evaluate psychotherapeutic effects. Furthermore, this perspective article suggests alternative methodologies that may be useful, namely, the single- and multi-session evaluations using immediate pre- and post-intervention measurements. These methods can be used to evaluate state changes in brain activity, which can be derived from a single session of psychotherapeutic interventions. This article provides a conceptual schema important in actualizing NIRS application for evidence-base psychotherapy.

A Review on Research and Evaluation Methods for Investigating Self-Transcendence

Self-transcendence has been characterized as a decrease in self-saliency (ego disillusionment) and increased connection, and has been growing in research interest in the past decade. Several measures have been developed and published with some degree of psychometric validity and reliability. However, to date, there has been no review systematically describing, contrasting, and evaluating the different methodological approaches toward measuring self-transcendence including questionnaires, neurological and physiological measures, and qualitative methods. To address this gap, we conducted a review to describe existing methods of measuring self-transcendence, evaluate the strengths and weaknesses of these methods, and discuss research avenues to advance assessment of self-transcendence, including recommendations for suitability of methods given research contexts.

NIRS measures in pain and analgesia: Fundamentals, features, and function

Current pain assessment techniques based only on clinical evaluation and self-reports are not objective and may lead to inadequate treatment. Having a functional biomarker will add to the clinical fidelity, diagnosis, and perhaps improve treatment efficacy in patients. While many approaches have been deployed in pain biomarker discovery, functional near-infrared spectroscopy (fNIRS) is a technology that allows for non-invasive measurement of cortical hemodynamics. The utility of fNIRS is especially attractive given its ability to detect specific changes in the somatosensory and high-order cortices as well as its ability to measure (1) brain function similar to functional magnetic resonance imaging, (2) graded responses to noxious and innocuous stimuli, (3) analgesia, and (4) nociception under anesthesia. In this review, we evaluate the utility of fNIRS in nociception/pain with particular focus on its sensitivity and specificity, methodological advantages and limitations, and the current and potential applications in various pain conditions. Everything considered, fNIRS technology could enhance our ability to evaluate evoked and persistent pain across different age groups and clinical populations.

Functional Near-Infrared Spectroscopy to Assess Central Pain Responses in a Nonpharmacologic Treatment Trial of Osteoarthritis

BACKGROUND AND PURPOSE

Knee osteoarthritis (OA) is a common source of pain in older adults. Although OA-induced pain can be relieved with analgesics and anti-inflammatory drugs, the current opioid epidemic is fostering the exploration of nonpharmacologic strategies for pain mitigation. Amongs these, transcranial direct current stimulation (tDCS) and mindfulness-based meditation (MBM) hold potential for pain-relief efficacy due to their neuromodulatory effects of the central nervous system, which is known to play a fundamental role in pain perception and processing.

METHODS

In this double-blind study, we used functional near-infrared spectroscopy (fNIRS) to investigate the effects of tDCS combined with MBM on underlying pain processing mechanisms at the central nervous level in older adults with knee OA. Nineteen subjects were randomly assigned to two groups undergoing a 10-day active tDCS and MBM regimen and a sham tDCS and MBM regimen, respectively.

RESULTS

Our results showed that the neuromodulatory intervention significantly relieved pain only in the group receiving active treatment. We also found that only the active treatment group showed a significant increase in oxyhemoglobin activation of the superior motor and somatosensory cortices colocated to the placement of the tDCS anodal electrode. To our knowledge, this is the first study in which the combined effect of tDCS and MBM is investigated using fNIRS.

CONCLUSION

In conclusion, fNIRS can be effectively used to investigate neural mechanisms of pain at the cortical level in association with nonpharmacological, self-administered treatments.

Neural correlates of mindful emotion regulation in high and low ruminators

Depressive rumination is considered a prominent risk factor for the occurrence, severity, and duration of depressive episodes. A variety of treatment options have been developed to treat depressive rumination of which mindfulness based programs are especially promising. In the current study, we investigated the neural underpinnings of a short mindfulness intervention and mindful emotion regulation in high and low trait ruminators in an ecologically valid environment using functional near-infrared spectroscopy (fNIRS). Participants were randomly assigned to a mindfulness instruction (MT) group or an instructed thinking (IT) group. Participants in the MT group were trained to either focus their attention mindfully on their breath or their emotions, while the IT group focused their attention on the past or future. Afterwards, all participants underwent an emotion regulation paradigm in which they either watched negative or neutral movie clips. During both paradigms cortical hemodynamic changes were assessed by means of fNIRS. Participants in the MT group showed lower activity in the cognitive control network (CCN) during the focus on breath condition in comparison to the focus on emotion condition. Additionally, oxygenated hemoglobin in the MT group tended to be lower than in the IT group. Further, self-reports of emotional distress during the instruction paradigm were reduced in the MT group. During the emotion regulation paradigm, we observed reduced emotional reactivity in terms of emotional distress and avoidance in the MT group in comparison to the IT group. Furthermore, on a neural level, we observed higher CCN activity in the MT group in comparison to the IT group. We did not find any effect of rumination, neither on the intervention nor on the emotion regulation task. The results of this pilot study are discussed in light of the present literature on the neural correlates of mindfulness based interventions in rumination and emphasize the use of fNIRS to track neural changes in situ over the course of therapy.

Short-Term Effects of Meditation on Sustained Attention as Measured by fNIRS

Cognitive abilities such as attention, memory, processing time, perception, and reasoning can be augmented using some type of intervention. Within the broad range of conventional and unconventional intervention methods used in cognitive enhancement, meditation is one of those that is safe, widely practiced by many since ancient times, and has been shown to reduce stress and improve psychological health and cognitive functioning. Various neuroimaging studies using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) have shown functional and structural changes due to meditation in different types of meditation practices and on various groups of meditators. Recently, a few studies on meditation have used functional near infrared spectroscopy (fNIRS) to study the effects of meditation on cerebral hemodynamics. In this study, we examined the short-term effects of loving-kindness (LK) meditation on sustained attention using behavioral performance measures, physiological outcomes, and cognitive activity as measured by fNIRS in first-time meditators during Stroop color word task (SCWT) performance. Our results indicated that behavioral outcomes, assessed mainly on response time (RT) during SCWT performance, showed a significant decrease after meditation. As expected, physiological measures, primarily pulse pressure (PP) measured after meditation dropped significantly as compared to the before meditation measurement. For the hemodynamic measures of oxygenated-hemoglobin (HbO2), deoxygenated-hemoglobin (Hb), and total-hemoglobin (HbT), our findings show significant differences in SCWT performance before and after meditation. Our results suggest that LK meditation can result in improvements in cognitive, physiological, and behavioral outcomes of first-time meditators after a short-term session.

Prefrontal Cortical Activation While Doing Mindfulness Task: a Pilot Functional Near-Infrared Spectroscopy Study

Mindfulness interventions are increasingly used in clinical settings. Neurophysiological mechanisms underlying mindfulness offer objective evidence that can help us evaluate the efficacy of mindfulness. Recent advances in technology have facilitated the use of functional Near-Infrared Spectroscopy (fNIRS) as a light weight, portable, and relatively lower cost neuroimaging device as compared to functional Magnetic Resonance Imaging (fMRI). In contrast to numerous fMRI studies, there are scanty investigations using fNIRS to study mindfulness. Hence, this study was done to investigate the feasibility of using a continuous-wave multichannel fNIRS system to study cerebral cortex activations on a mindfulness task versus a baseline task. NIRS data from 14 healthy Asian subjects were collected. A statistical parametric mapping toolbox specific for statistical analysis of NIRS signal called NIRS_SPM was used to study the activations. The results from group analysis performed on the contrast of the mindfulness versus baseline tasks showed foci of activations on the left and central parts of the prefrontal cortex. The findings are consistent with prevailing fMRI studies and show promise of using fNIRS system for studying real-time neurophysiological cortical activations during mindfulness practice.

Enhancing Attention by Synchronizing Respiration and Fingertip Pressure: A Pilot Study Using Functional Near-Infrared Spectroscopy

Sustained attention is a fundamental ability ensuring effective cognitive processing and can be enhanced by meditation practice. However, keeping a focused meditative state is challenging for novices because involuntary mind-wandering frequently occurs during their practice. Inspired by the potential of force-control tasks in invoking internal somatic attention, we proposed a haptics-assisted meditation (HAM) to help reduce mind-wandering and enhance attention. During HAM, participants were instructed to maintain awareness on the respiration and meanwhile adjust bimanual fingertip pressures to keep synchronized with the respiration. This paradigm required somatosensory attention as a physiological foundation, aiming to help novices meditate starting with the body and gradually gain essential meditation skills. A cross-sectional study on 12 novices indicated that the participants reported less mind-wandering during HAM compared with the classic breath-counting meditation (BCM). In a further longitudinal study, the experimental group with 10 novices showed significantly improved performance in several attentional tests after 5 days' practice of HAM. They tended to show more significant improvements in a few tests than did the control group performing the 5-day BCM practice. To investigate the brain activities related to HAM, we applied functional near-infrared spectroscopy (fNIRS) to record cerebral hemodynamic responses from the prefrontal and sensorimotor cortices when performing HAM, and we assessed the changes in cerebral activation and functional connectivity (FC) after the 5-day HAM practice. The prefrontal and sensorimotor regions demonstrated a uniform activation when performing HAM, and there was a significant increase in the right prefrontal activation after the practice. We also observed significant changes in the FC between the brain regions related to the attention networks. These behavioral and neural findings together provided preliminary evidence for the effectiveness of HAM on attention enhancement in the early stage of meditation learning.

Mindfulness and hemodynamics in asians: a literature review

INTRODUCTION

Mindfulness interventions have been increasingly incorporated into clinical settings. Evidence supporting mindfulness practices are predominantly established in Western populations. Neurophysiological evidence has not been established to support the effectiveness of mindfulness practice in Asian populations. Greater understanding of the neurophysiological mechanisms underlying mindfulness would enable hemodynamics as measured by fNIRS to be used to monitor mindfulness practice as an adjunct to psychotherapy with Asian clients.

METHOD

Research relating to fNIRS and hemodynamics for mindfulness in Asians was reviewed. The inclusion criteria for this review were recent publications in peer-reviewed journals from 2008 to 2018, with the search terms 'fNIRS', 'hemodynamics' and 'mindfulness', for studies in Asia.

FINDINGS

Databases included Medline, PubMed, PSYCINFO, Google Scholar and SCOPUS. Initial searches yielded 86 results. Five duplicated articles were removed, and remaining abstracts were screened; and assessed for eligibility against the structured performa. Three full text papers which fit the inclusion criteria were included in the current review.

CONCLUSION

This review highlighted the paucity of rigorous empirically validated research for hemodynamics as measured with fNIRS for mindfulness practice in Asia.

Applying Mindfulness-Based Practices in Child Psychiatry

Mindfulness-based interventions for adults, children, and families have grown considerably, and burgeoning evidence supports use of these approaches for a range of clinical presentations, including anxiety, depression, ADHD, and addiction. Research into the mechanisms of mindfulness suggests improvements in key brain-based functions including attentional control and emotional regulation. Mindfulness may be relevant for improving emotional and behavioral symptoms in children and families presenting for psychiatric care and also may be an important universal strategy to promote brain health. Child psychiatrists should be familiar with mindfulness-based clinical programs and also may seek to develop mindfulness-based strategies to use in clinical practice.

Mind-Body Interactions and Mindfulness Meditation in Diabetes

Diabetes is associated with significant psychological distress. It is, therefore, important to ensure the physical and emotional as well as psychosocial wellbeing of individuals living with diabetes. Meditation-based strategies have been evaluated for their complementary role in several chronic disorders including depression, anxiety, obesity, hypertension, cardiovascular disease and diabetes. The practice of meditation is associated with reduction in stress and negative emotions and improvements in patient attitude, health-related behaviour and coping skills. There is increased parasympathetic activity with reduction in sympathetic vascular tone, stress hormones and inflammatory markers. Additionally, several studies evaluated the role of mindfulness-based stress reduction in diabetic individuals and demonstrated modest improvements in body weight, glycaemic control and blood pressure. Thus, mindfulness meditation-based intervention can lead to improvements across all domains of holistic care – biological, psychological and social. Though most of these studies have been of short duration and included small numbers of patients, meditation strategies can be useful adjunctive techniques to lifestyle modification and pharmacological management of diabetes and help improve patient wellbeing.