Fadel Zeidan

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 4days of meditation training can enhance the ability to sustain attention; benefits that have previously been reported with long-term meditators.

Brain Mechanisms Supporting the Modulation of Pain by Mindfulness Meditation

The subjective experience of ones environment is constructed by interactions among sensory, cognitive, and affective processes. For centuries, meditation has been thought to influence such processes by enabling a nonevaluative representation of sensory events. To better understand how meditation influences the sensory experience, we used arterial spin labeling functional magnetic resonance imaging to assess the neural mechanisms by which mindfulness meditation influences pain in healthy human participants. After 4 d of mindfulness meditation training, meditating in the presence of noxious stimulation significantly reduced pain unpleasantness by 57% and pain intensity ratings by 40% when compared to rest. A two-factor repeated-measures ANOVA was used to identify interactions between meditation and pain-related brain activation. Meditation reduced pain-related activation of the contralateral primary somatosensory cortex. Multiple regression analysis was used to identify brain regions associated with individual differences in the magnitude of meditation-related pain reductions. Meditation-induced reductions in pain intensity ratings were associated with increased activity in the anterior cingulate cortex and anterior insula, areas involved in the cognitive regulation of nociceptive processing. Reductions in pain unpleasantness ratings were associated with orbitofrontal cortex activation, an area implicated in reframing the contextual evaluation of sensory events. Moreover, reductions in pain unpleasantness also were associated with thalamic deactivation, which may reflect a limbic gating mechanism involved in modifying interactions between afferent input and executive-order brain areas. Together, these data indicate that meditation engages multiple brain mechanisms that alter the construction of the subjectively available pain experience from afferent information.

Mindfulness meditation-related pain relief: evidence for unique brain mechanisms in the regulation of pain.

The cognitive modulation of pain is influenced by a number of factors ranging from attention, beliefs, conditioning, expectations, mood, and the regulation of emotional responses to noxious sensory events. Recently, mindfulness meditation has been found attenuate pain through some of these mechanisms including enhanced cognitive and emotional control, as well as altering the contextual evaluation of sensory events. This review discusses the brain mechanisms involved in mindfulness meditation-related pain relief across different meditative techniques, expertise and training levels, experimental procedures, and neuroimaging methodologies. Converging lines of neuroimaging evidence reveal that mindfulness meditation-related pain relief is associated with unique appraisal cognitive processes depending on expertise level and meditation tradition. Moreover, it is postulated that mindfulness meditation-related pain relief may share a common final pathway with other cognitive techniques in the modulation of pain.

Effects of Brief and Sham Mindfulness Meditation on Mood and Cardiovascular Variables

OBJECTIVES Although long-term meditation has been found to reduce negative mood and cardiovascular variables, the effects of a brief mindfulness meditation intervention when compared to a sham mindfulness meditation intervention are relatively unknown. This experiment examined whether a 3-day (1-hour total) mindfulness or sham mindfulness meditation intervention would improve mood and cardiovascular variables when compared to a control group. METHODS Eighty-two (82) undergraduate students (34 males, 48 females), with no prior meditation experience, participated in three sessions that involved training in either mindfulness meditation, sham mindfulness meditation, or a control group. Heart rate, blood pressure, and psychologic variables (Profile of Mood States, State Anxiety Inventory) were assessed before and after the intervention. RESULTS The meditation intervention was more effective at reducing negative mood, depression, fatigue, confusion, and heart rate, when compared to the sham and control groups. CONCLUSIONS These results indicate that brief meditation training has beneficial effects on mood and cardiovascular variables that go beyond the demand characteristics of a sham meditation intervention.

The downward spiral of chronic pain, prescription opioid misuse, and addiction: Cognitive, affective, and neuropsychopharmacologic pathways

Prescription opioid misuse and addiction among chronic pain patients are emerging public health concerns of considerable significance. Estimates suggest that more than 10% of chronic pain patients misuse opioid analgesics, and the number of fatalities related to nonmedical or inappropriate use of prescription opioids is climbing. Because the prevalence and adverse consequences of this threat are increasing, there is a pressing need for research that identifies the biobehavioral risk chain linking chronic pain, opioid analgesia, and addictive behaviors. To that end, the current manuscript draws upon current neuropsychopharmacologic research to provide a conceptual framework of the downward spiral leading to prescription opioid misuse and addiction among chronic pain patients receiving opioid analgesic pharmacotherapy. Addictive use of opioids is described as the outcome of a cycle initiated by chronic pain and negative affect and reinforced by opioidergic-dopamingeric interactions, leading to attentional hypervigilance for pain and drug cues, dysfunctional connectivity between self-referential and cognitive control networks in the brain, and allostatic dysregulation of stress and reward circuitry. Implications for clinical practice are discussed; multimodal, mindfulness-oriented treatment is introduced as a potentially effective approach to disrupting the downward spiral and facilitating recovery from chronic pain and opioid addiction.

Mindfulness Meditation-Based Pain Relief Employs Different Neural Mechanisms Than Placebo and Sham Mindfulness Meditation-Induced Analgesia

Mindfulness meditation reduces pain in experimental and clinical settings. However, it remains unknown whether mindfulness meditation engages pain-relieving mechanisms other than those associated with the placebo effect (e.g., conditioning, psychosocial context, beliefs). To determine whether the analgesic mechanisms of mindfulness meditation are different from placebo, we randomly assigned 75 healthy, human volunteers to 4 d of the following: (1) mindfulness meditation, (2) placebo conditioning, (3) sham mindfulness meditation, or (4) book-listening control intervention. We assessed intervention efficacy using psychophysical evaluation of experimental pain and functional neuroimaging. Importantly, all cognitive manipulations (i.e., mindfulness meditation, placebo conditioning, sham mindfulness meditation) significantly attenuated pain intensity and unpleasantness ratings when compared to rest and the control condition (p < 0.05). Mindfulness meditation reduced pain intensity (p = 0.032) and pain unpleasantness (p < 0.001) ratings more than placebo analgesia. Mindfulness meditation also reduced pain intensity (p = 0.030) and pain unpleasantness (p = 0.043) ratings more than sham mindfulness meditation. Mindfulness-meditation-related pain relief was associated with greater activation in brain regions associated with the cognitive modulation of pain, including the orbitofrontal, subgenual anterior cingulate, and anterior insular cortex. In contrast, placebo analgesia was associated with activation of the dorsolateral prefrontal cortex and deactivation of sensory processing regions (secondary somatosensory cortex). Sham mindfulness meditation-induced analgesia was not correlated with significant neural activity, but rather by greater reductions in respiration rate. This study is the first to demonstrate that mindfulness-related pain relief is mechanistically distinct from placebo analgesia. The elucidation of this distinction confirms the existence of multiple, cognitively driven, supraspinal mechanisms for pain modulation. SIGNIFICANCE STATEMENT Recent findings have demonstrated that mindfulness meditation significantly reduces pain. Given that the “gold standard” for evaluating the efficacy of behavioral interventions is based on appropriate placebo comparisons, it is imperative that we establish whether there is an effect supporting meditation-related pain relief above and beyond the effects of placebo. Here, we provide novel evidence demonstrating that mindfulness meditation produces greater pain relief and employs distinct neural mechanisms than placebo cream and sham mindfulness meditation. Specifically, mindfulness meditation-induced pain relief activated higher-order brain regions, including the orbitofrontal and cingulate cortices. In contrast, placebo analgesia was associated with decreased pain-related brain activation. These findings demonstrate that mindfulness meditation reduces pain through unique mechanisms and may foster greater acceptance of meditation as an adjunct pain therapy.

Neural correlates of mindfulness meditation-related anxiety relief

Anxiety is the cognitive state related to the inability to control emotional responses to perceived threats. Anxiety is inversely related to brain activity associated with the cognitive regulation of emotions. Mindfulness meditation has been found to regulate anxiety. However, the brain mechanisms involved in meditation-related anxiety relief are largely unknown. We employed pulsed arterial spin labeling MRI to compare the effects of distraction in the form of attending to the breath (ATB; before meditation training) to mindfulness meditation (after meditation training) on state anxiety across the same subjects. Fifteen healthy subjects, with no prior meditation experience, participated in 4 d of mindfulness meditation training. ATB did not reduce state anxiety, but state anxiety was significantly reduced in every session that subjects meditated. Meditation-related anxiety relief was associated with activation of the anterior cingulate cortex, ventromedial prefrontal cortex and anterior insula. Meditation-related activation in these regions exhibited a strong relationship to anxiety relief when compared to ATB. During meditation, those who exhibited greater default-related activity (i.e. posterior cingulate cortex) reported greater anxiety, possibly reflecting an inability to control self-referential thoughts. These findings provide evidence that mindfulness meditation attenuates anxiety through mechanisms involved in the regulation of self-referential thought processes.

Pain sensitivity is inversely related to regional grey matter density in the brain.

Summary Highly sensitive individuals had the least grey matter density in the bilateral precuneus, posterior cingulate cortex, posterior parietal cortex, and left primary somatosensory cortex. ABSTRACT Pain is a highly personal experience that varies substantially among individuals. In search of an anatomical correlate of pain sensitivity, we used voxel‐based morphometry to investigate the relationship between grey matter density across the whole brain and interindividual differences in pain sensitivity in 116 healthy volunteers (62 women, 54 men). Structural magnetic resonance imaging (MRI) and psychophysical data from 10 previous functional MRI studies were used. Age, sex, unpleasantness ratings, scanner sequence, and sensory testing location were added to the model as covariates. Regression analysis of grey matter density across the whole brain and thermal pain intensity ratings at 49 °C revealed a significant inverse relationship between pain sensitivity and grey matter density in bilateral regions of the posterior cingulate cortex, precuneus, intraparietal sulcus, and inferior parietal lobule. Unilateral regions of the left primary somatosensory cortex also exhibited this inverse relationship. No regions showed a positive relationship to pain sensitivity. These structural variations occurred in areas associated with the default mode network, attentional direction and shifting, as well as somatosensory processing. These findings underscore the potential importance of processes related to default mode thought and attention in shaping individual differences in pain sensitivity and indicate that pain sensitivity can potentially be predicted on the basis of brain structure.

Mindfulness-Meditation-Based Pain Relief Is Not Mediated by Endogenous Opioids

Mindfulness meditation, a cognitive practice premised on sustaining nonjudgmental awareness of arising sensory events, reliably attenuates pain. Mindfulness meditation activates multiple brain regions that contain a high expression of opioid receptors. However, it is unknown whether mindfulness-meditation-based analgesia is mediated by endogenous opioids. The present double-blind, randomized study examined behavioral pain responses in healthy human volunteers during mindfulness meditation and a nonmanipulation control condition in response to noxious heat and intravenous administration of the opioid antagonist naloxone (0.15 mg/kg bolus + 0.1 mg/kg/h infusion) or saline placebo. Meditation during saline infusion significantly reduced pain intensity and unpleasantness ratings when compared to the control + saline group. However, naloxone infusion failed to reverse meditation-induced analgesia. There were no significant differences in pain intensity or pain unpleasantness reductions between the meditation + naloxone and the meditation + saline groups. Furthermore, mindfulness meditation during naloxone produced significantly greater reductions in pain intensity and unpleasantness than the control groups. These findings demonstrate that mindfulness meditation does not rely on endogenous opioidergic mechanisms to reduce pain. SIGNIFICANCE STATEMENT Endogenous opioids have been repeatedly shown to be involved in the cognitive inhibition of pain. Mindfulness meditation, a practice premised on directing nonjudgmental attention to arising sensory events, reduces pain by engaging mechanisms supporting the cognitive control of pain. However, it remains unknown if mindfulness-meditation-based analgesia is mediated by opioids, an important consideration for using meditation to treat chronic pain. To address this question, the present study examined pain reports during meditation in response to noxious heat and administration of the opioid antagonist naloxone and placebo saline. The results demonstrate that meditation-based pain relief does not require endogenous opioids. Therefore, the treatment of chronic pain may be more effective with meditation due to a lack of cross-tolerance with opiate-based medications.

From cue to meaning: Brain mechanisms supporting the construction of expectations of pain

Summary Cues arising from different sensory modalities ultimately engage common brain mechanisms that reflect the meaning of the cue. ABSTRACT The brain mechanisms by which sensory cues become transformed into expectations of impending events are a critical component of cognitive tuning of sensory processing. However, distinctions among the afferent processing of cue‐related activity itself versus those mechanisms supporting the contextual meaning imparted to the cue remain limited. Do sensory cues with equal meaning engage similar patterns of brain activations even if they are delivered in separate modalities? To address this question, we used functional magnetic resonance imaging of an expectation paradigm in which cues were delivered with visual or innocuous thermal stimuli. Cues were designed to be highly meaningful because they predicted the delivery of high and low painful stimuli. As expected, the cues themselves activated unimodal sensory cortices. This cue modality‐specific activation was transformed into a pattern of activity reflecting cue meaning. Cues signaling high pain produced greater activity in the left dorsolateral prefrontal cortex and anterior cingulate cortex. Such activity is consistent with the graded encoding of the magnitude of expected pain. In contrast, cues signaling low pain produced greater activity in the right intraparietal sulcus. This activation may reflect processes directing spatial attention to the stimulated body region in order to more accurately evaluate the relatively weak, low pain stimulus. Taken together, these findings indicate that cues arising from different sensory modalities ultimately engage common brain mechanisms that reflect the meaning of the cue. This meaning‐related activity is presumably critical for preparing sensory systems to optimally process afferent information.