Long-term meditation training induced changes in the operational synchrony of default mode network modules during a resting state

Using theoretical analysis of self-consciousness concept and experimental evidence on the brain default mode network (DMN) that constitutes the neural signature of self-referential processes, we hypothesized that the anterior and posterior subnets comprising the DMN should show differences in their integrity as a function of meditation training. Functional connectivity within DMN and its subnets (measured by operational synchrony) has been measured in ten novice meditators using an electroencephalogram (EEG) recording in a pre-/post-meditation intervention design. We have found that while the whole DMN was clearly suppressed, different subnets of DMN responded differently after 4 months of meditation training: The strength of EEG operational synchrony in the right and left posterior modules of the DMN decreased in resting post-meditation condition compared to a pre-meditation condition, whereas the frontal DMN module on the contrary exhibited an increase in the strength of EEG operational synchrony. These findings combined with published data on functional–anatomic heterogeneity within the DMN and on trait subjective experiences commonly found following meditation allow us to propose that the first-person perspective and the sense of agency (the witnessing observer) are presented by the frontal DMN module, while the posterior modules of the DMN are generally responsible for the experience of the continuity of ‘I’ as embodied and localized within bodily space. Significance of these findings is discussed.     

Coherence between emotional experience and physiology: does body awareness training have an impact?

Two fundamental issues in emotion theory and research concern: (a) the role of emotion in promoting response coherence across different emotion systems; and (b) the role of awareness of bodily sensations in the experience of emotion. The present study poses a question bridging the two domains; namely, whether training in Vipassana meditation or dance, both of which promote attention to certain kinds of bodily sensations, is associated with greater coherence between the subjective and physiological aspects of emotion. We used lag correlations to examine second-by-second coherence between subjective emotional experience and heart period within individuals across four different films. Participants were either: (a) experienced Vipassana meditators (attention to visceral sensations), (b) experienced dancers (attention to somatic sensations), and (c) controls with no meditation or dance experience. Results indicated a linear relationship in coherence, with meditators having highest levels, dancers having intermediary levels, and controls having lowest levels. We conclude that the coherence between subjective and cardiac aspects of emotion is greater in those who have specialized training that promotes greater body awareness.     

A single session of meditation reduces of physiological indices of anger in both experienced and novice meditators

The goal of the present study was to explore how anger reduction via a single session of meditation might be measured using psychophysiological methodologies. To achieve this, 15 novice meditators (Experiment 1) and 12 practiced meditators (Experiment 2) completed autobiographical anger inductions prior to, and following, meditation training while respiration rate, heart rate, and blood pressure were measured. Participants also reported subjective anger via a visual analog scale. At both stages, the experienced meditators’ physiological reaction to the anger induction reflected that of relaxation: slowed breathing and heart rate and decreased blood pressure. Naïve meditators exhibited physiological reactions that were consistent with anger during the pre-meditation stage, while after meditation training and a second anger induction they elicited physiological evidence of relaxation. The current results examining meditation training show that the naïve group’s physiological measures mimicked those of the experienced group following a single session of meditation training.     

The happy face of mindfulness: Mindfulness meditation is associated with perceptions of happiness as rated by outside observers

The last decade has witnessed an enormous increase in research examining the effects of mindfulness meditation. One of the basic assumptions guiding this research is that meditation ultimately makes people happier. In this article, in two studies we tested whether meditators actually look happier. To address this question, outside raters judged the happiness of meditators and non-meditators based on a 15-s video clip of their behaviour. Study 1 demonstrated that novice meditators looked happier after an intensive 9-day meditation retreat (as compared to before the retreat), while Study 2 demonstrated that experienced mindfulness meditators looked happier as compared to controls. The interpersonal implications of these findings are discussed.     

Effect of Transcendental Meditation versus resting on physiological and subjective arousal

On four successive days, 10 highly trained and experienced meditators were asked to relax for 5 minutes, meditate for 20 minutes, and then relax for 5 minutes. In contrast, 10 other subjects who had no training or experience with meditation were asked to relax for 5 minutes, rest for 20 minutes, and then relax for 5 minutes. Physiological arousal (heart rate, skin resistance, respiration rate, systolic blood pressure, diastolic blood pressure) and subjective arousal (cognitive, somatic, relaxation) were measured throughout the experiment. Results indicated that (a) prior to meditating or resting, meditators tended to have higher heart rates and diastolic blood pressure than did nonmeditators, (b) meditation was associated with generally reduced arousal, but (c) while meditating, meditators did not evidence lower levels of arousal than nonmeditators did while resting. This investigation employed controls, which were not used in previous investigations, and the results place qualifications on previously reported results. The results have implications for the study of personality functioning, stress management, and psychotherapy.     

Mindfulness meditation improves cognition: Evidence of brief mental training

Although research has found that long-term mindfulness meditation practice promotes executive functioning and the ability to sustain attention, the effects of brief mindfulness meditation training have not been fully explored. We examined whether brief meditation training affects cognition and mood when compared to an active control group. After four sessions of either meditation training or listening to a recorded book, participants with no prior meditation experience were assessed with measures of mood, verbal fluency, visual coding, and working memory. Both interventions were effective at improving mood but only brief meditation training reduced fatigue, anxiety, and increased mindfulness. Moreover, brief mindfulness training significantly improved visuo-spatial processing, working memory, and executive functioning. Our findings suggest that 4 days of meditation training can enhance the ability to sustain attention; benefits that have previously been reported with long-term meditators.     

Control over experience? Magnitude of the attentional blink depends on meditative state

The information processing capacity of the human mind is limited, as is evidenced by the so-called ‘attentional-blink’ deficit. This deficit is believed to result from competition between stimuli for limited attentional resources. We examined to what extent advanced meditators can manipulate their attentional state and control performance on an attentional blink task. We compared the magnitude of the attentional blink between states of focused attention meditation (in which one focuses tightly on an object) and states of open monitoring meditation (in which one is simply aware of whatever comes into experience) in a sample of experienced meditators. We found a smaller attentional blink during open monitoring compared to focused attention meditation due to reduced T1 capture. Of note, this effect was only found for very experienced meditators (on average 10,704 h of experience). These data may suggest that very advanced practitioners can exert some control over their conscious experience.     

Awareness of subtle emotional feelings: a comparison of long-term meditators and nonmeditators

The authors explored whether meditation training to enhance emotional awareness improves discrimination of subtle emotional feelings hypothesized to guide decision-making. Long-term meditators and nonmeditators were compared on measures of self-reported valence and arousal, skin conductance response (SCR), and facial electromyography (EMG) to masked and nonmasked emotional pictures, and on measures of heartbeat detection and self-reported emotional awareness. Groups responded similarly to nonmasked pictures. In the masked condition, only controls showed discrimination in valence self-reports. However, meditators reported greater emotional clarity than controls, and meditators with higher clarity had reduced arousal and improved valence discrimination in the masked condition. These findings provide qualified support for the somatic marker hypothesis and suggest that meditation may influence how emotionally ambiguous information is processed, regulated, and represented in conscious awareness.     

Cerebral blood flow differences between long-term meditators and non-meditators

We have studied a number of long-term meditators in previous studies. The purpose of this study was to determine if there are differences in baseline brain function of experienced meditators compared to non-meditators. All subjects were recruited as part of an ongoing study of different meditation practices. We evaluated 12 advanced meditators and 14 non-meditators with cerebral blood flow (CBF) SPECT imaging at rest. Images were analyzed with both region of interest and statistical parametric mapping. The CBF of long-term meditators was significantly higher (p < .05) compared to non-meditators in the prefrontal cortex, parietal cortex, thalamus, putamen, caudate, and midbrain. There was also a significant difference in the thalamic laterality with long-term meditators having greater asymmetry. The observed changes associated with long-term meditation appear in structures that underlie the attention network and also those that relate to emotion and autonomic function.     

Effects of long-term meditation practice on attentional biases towards emotional faces: An eye-tracking study

Attentional biases towards affective stimuli reflect an individual balance of appetitive and aversive motivational systems. Vigilance in relation to threatening information reflects emotional imbalance, associated with affective and somatic problems. It is known that meditation practice significantly improves control of attention, which is considered to be a tool for adaptive emotional regulation. In this regard, the main aim of the present study was to evaluate the influence of meditation on attentional bias towards neutral and emotional facial expressions. Eyes were tracked while 21 healthy controls and 23 experienced meditators (all males) viewed displays consisting of four facial expressions (neutral, angry, fearful and happy) for 10 s. Measures of biases in initial orienting and maintenance of attention were assessed. No effects were found for initial orienting biases. Meditators spent significantly less time viewing angry and fearful faces than control subjects. Furthermore, meditators selectively attended to happy faces whereas control subjects showed attentional biases towards both angry and happy faces. In sum we can conclude that long-term meditation practice adaptively affects attentional biases towards motivationally significant stimuli and that these biases reflect positive mood and predominance of appetitive motivation.     

Meditation,well-being and cognition in heartfulness meditators – A pilot study

Meditative practices can vary considerably in technique as well as their effects. Heartfulness is a popular meditation technique that includes in its repertoire, a unique passive form of meditation. We carried out a pilot study recruiting male heartfulness meditators (proficient n = 24, with 6–28 years of meditation experience; novice n = 24, 5 to 16 months of experience) and subsequently recruited matched controls (n = 15). We examined well-being, and carried out high-density EEG recordings to examine indices of meditation and cognition in these groups. Well-being scores were significantly higher for the proficient meditators as compared to novice and intermediate for the controls. We did not find any group differences in cognitive processing. During meditation, enhanced occipital gamma was found in proficient meditators as compared to controls. We discuss the findings from this pilot study and suggest avenues for future research.     

Mindfulness and self-compassion as predictors of psychological wellbeing in long-term meditators and matched nonmeditators

Mindfulness training has well-documented effects on psychological health. Recent findings suggest that increases in both mindfulness and self-compassion may mediate these outcomes; however, their separate and combined effects are rarely examined in the same participants. This study investigated cross-sectional relationships between self-reported mindfulness, self-compassion, meditation experience, and psychological wellbeing in 77 experienced meditators and 75 demographically matched nonmeditators. Most mindfulness and self-compassion scores were significantly correlated with meditation experience and psychological wellbeing. Mindfulness and self-compassion accounted for significant independent variance in wellbeing. A significant relationship between meditation experience and wellbeing was completely accounted for by a combination of mindfulness and self-compassion scores. Findings suggest that both mindfulness and self-compassion skills may play important roles in the improved wellbeing associated with mindfulness training; however, longitudinal studies are needed to confirm these findings.     

Occipital gamma activation during Vipassana meditation

Long-term Vipassana meditators sat in meditation vs. a control rest (mind-wandering) state for 21 min in a counterbalanced design with spontaneous EEG recorded. Meditation state dynamics were measured with spectral decomposition of the last 6 min of the eyes-closed silent meditation compared to control state. Meditation was associated with a decrease in frontal delta (1–4 Hz) power, especially pronounced in those participants not reporting drowsiness during meditation. Relative increase in frontal theta (4–8 Hz) power was observed during meditation, as well as significantly increased parieto-occipital gamma (35–45 Hz) power, but no other state effects were found for the theta (4–8 Hz), alpha (8–12 Hz), or beta (12–25 Hz) bands. Alpha power was sensitive to condition order, and more experienced meditators exhibited no tendency toward enhanced alpha during meditation relative to the control task. All participants tended to exhibit decreased alpha in association with reported drowsiness. Cross-experimental session occipital gamma power was the greatest in meditators with a daily practice of 10+ years, and the meditation-related gamma power increase was similarly the strongest in such advanced practitioners. The findings suggest that long-term Vipassana meditation contributes to increased occipital gamma power related to long-term meditational expertise and enhanced sensory awareness.     

Meditation,mindfulness and cognitive flexibility

This study investigated the link between meditation, self-reported mindfulness and cognitive flexibility as well as other attentional functions. It compared a group of meditators experienced in mindfulness meditation with a meditation-naïve control group on measures of Stroop interference and the “d2-concentration and endurance test”. Overall the results suggest that attentional performance and cognitive flexibility are positively related to meditation practice and levels of mindfulness. Meditators performed significantly better than non-meditators on all measures of attention. Furthermore, self-reported mindfulness was higher in meditators than non-meditators and correlations with all attention measures were of moderate to high strength. This pattern of results suggests that mindfulness is intimately linked to improvements of attentional functions and cognitive flexibility. The relevance of these findings for mental balance and well-being are discussed.     

Mindfulness meditation and relaxation training increases time sensitivity

Two experiments examined the effect of mindfulness meditation and relaxation on time perception using a temporal bisection task. In Experiment 1, the participants performed a temporal task before and after exercises of mindfulness meditation or relaxation. In Experiment 2, the procedure was similar than that used in Experiment 1, except that the participants were trained to mediate or relax every day over a period of several weeks. The results showed that mindfulness meditation exercises increased sensitivity to time and lengthened perceived time. However, this temporal improvement with meditation exercises was primarily observed in the experienced meditators. Our results also showed the experienced meditators were less anxious than the novice participants, and that the sensitivity to time increased when the level of anxiety decreased. Our results were explained by the practice of mindfulness technique that had developed individuals’ abilities in devoting more attention resources to temporal information processing.     

Construct validity of the five facet mindfulness questionnaire in meditating and nonmeditating samples

Previous research on assessment of mindfulness by self-report suggests that it may include five component skills: observing, describing, acting with awareness, nonjudging of inner experience, and nonreactivity to inner experience. These elements of mindfulness can be measured with the Five Facet Mindfulness Questionnaire (FFMQ). The authors investigated several aspects of the construct validity of the FFMQ in experienced meditators and nonmeditating comparison groups. Consistent with predictions, most mindfulness facets were significantly related to meditation experience and to psychological symptoms and well-being. As expected, relationships between the observing facet and psychological adjustment varied with meditation experience. Regression and mediation analyses showed that several of the facets contributed independently to the prediction of well-being and significantly mediated the relationship between meditation experience and well-being. Findings support the construct validity of the FFMQ in a combination of samples not previously investigated.     

Attentional processes and meditation

Visual attentional processing was examined in adult meditators and non-meditators on behavioral measures of change blindness, concentration, perspective-shifting, selective attention, and sustained inattentional blindness. Results showed that meditators (1) noticed more changes in flickering scenes and noticed them more quickly, (2) counted more accurately in a challenging concentration task, (3) identified a greater number of alternative perspectives in multiple perspectives images, and (4) showed less interference from invalid cues in a visual selective attention task, but (5) did not differ on a measure of sustained inattentional blindness. Together, results show that regular meditation is associated with more accurate, efficient, and flexible visual attentional processing across diverse tasks that have high face validity outside of the laboratory. Furthermore, effects were assessed in a context separate from actual meditation practice, suggesting that meditators’ better visual attention is not just immediate, but extends to contexts separate from meditation practice.     

Cerebral blood flow during meditative prayer: preliminary findings and methodological issues

Meditative practices typically require several coordinated cognitive activities. This study measured changes in cerebral blood flow during "verbal" based meditation by Franciscan nuns involving the internal repetition of a particular phrase. These results are compared with those we previously described in eight Buddhist meditators who use a type of "visualization" technique. Three experienced practitioners of verbal meditation were injected via i.v. at rest with 260 MBq of Tc-99m HMPAO and scanned 30 min. later on a triple head SPECT camera for 45 min. Following the baseline scan, subjects meditated for approximately 40 min. at which time they were injected with 925 MBq of HMPAO while they continued to meditate for 10 min. more (total of 50 min. of meditation). The injection during meditation was designed not to disturb practice. Subjects were scanned 20 min. later for 30 min. Counts were obtained for regions of interest for major brain structures and normalized to whole-brain blood flow. Compared to baseline, mean verbal meditation scans showed increased blood flow in the prefrontal cortex (7.1%), inferior parietal lobes (6.8%), and inferior frontal lobes (9.0%). There was a strong inverse correlation between the blood flow, change in the prefrontal cortex and in the ipsilateral superior parietal lobe (p<.01). This study on a limited number of subjects demonstrated the feasibility of studying different types of meditation with neuroimaging techniques, suggested that several coordinated cognitive processes occur during meditation, and also raised important methodological issues.     

Breath Versus Emotions: The Impact of Different Foci of Attention During Mindfulness Meditation on the Experience of Negative and Positive Emotions

Mindfulness meditation yields beneficial effects on the processing of emotions. However, it is still unclear whether the focus of attention during meditation influences these effects. In the present study we aimed at comparing the effects of breathing meditation and emotion-focused meditation on the immediate and delayed processing of negative and positive emotions. The study included 65 adult novice meditators who were exposed to positively and negatively valenced film clips. Participants were randomly assigned to three conditions. While watching the films at t1, they were asked to mindfully focus on their breath (condition 1), on emotions (condition 2), or on nothing in particular (condition 3). Ten minutes later at t2, comparable film clips were shown but all participants watched them without taking up a mindful attitude. Dependent measures were emotional states at t1 and t2. Participants of both meditation conditions particularly showed a more preferable delayed emotional reaction to negative stimuli than participants of the control condition. Breathing meditation and emotion-focused meditation may constitute effective emotion regulation strategies to deal with negatively valenced emotional states.     

Intracerebral source generators characterizing concentrative meditation

Previous researchers have studied meditation practices as a means to understand consciousness as well as altered states of consciousness. Various meditation techniques, such as Transcendental Meditation (TM) and Qigong, have been explored with source localization tools; however, the concentrative meditation technique has yet to be fully studied in this manner. The current study demonstrates findings, which outline differential activation in a self-referential default network during meditation in participants who espouse themselves as regular concentrative meditation practitioners, as well as comparisons with a control group practicing a modified version of the relaxation response. The results are compared with other putative experimental findings employing other meditation techniques, and the findings outlined in the current study are discussed with respect to changes in perceptual awareness often reported by meditators.