PLoS One
March 25, 2008
Antoine Lutz, Julie A. Brefczynski-Lewis, Tom Johnstone et al.
942 citations
During loving-kindness-compassion meditation, expert practitioners show greater brain activation in the insula and limbic regions when hearing emotional sounds, especially negative ones, compared to novices. This enhanced response correlates with self-reported meditation intensity. Experts also exhibit increased activity in the amygdala, temporo-parietal junction, and posterior superior temporal sulcus, suggesting improved detection of emotional vocalizations and mental state reasoning. The findings indicate that training in cultivating positive emotion alters neural circuits associated with empathy and theory of mind.
PLoS One
August 31, 2010
Erich Studerus, Alex Gamma, Franz X. Vollenweider
693 citations
The original OAV scales measured multidimensional constructs. Eleven new lower-order scales were developed and showed good psychometric properties. These new scales are probably better for assessing altered states of consciousness caused by drugs.
PLoS One
April 16, 2015
Rinske A. Gotink, Paula Chu, Jan J. V. Busschbach et al.
546 citations
Mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT) modestly improve depressive symptoms, anxiety, stress, quality of life, and physical functioning across a range of chronic conditions. A systematic review and meta-analysis of 23 reviews covering 115 randomized controlled trials and 8,683 individuals found that, compared with waitlist or treatment as usual, these programs yielded small to moderate benefits: depressive symptoms (Cohen's d=0.37), anxiety (d=0.49), stress (d=0.51), quality of life (d=0.39), and physical functioning (d=0.27). The evidence supports their use as adjunct treatments for cancer, cardiovascular disease, chronic pain, depression, anxiety disorders, and prevention in healthy adults and children, though heterogeneity, possible publication bias, and limited long-term follow-up temper confidence.
PLoS One
September 2, 2014
Marwan N. Baliki, Ali Mansour, Alex T. Baria et al.
539 citations
Chronic pain reorganizes the brain's default mode network (DMN). Using resting-state functional magnetic resonance imaging, patients with chronic back pain, complex regional pain syndrome, and knee osteoarthritis all showed reduced connectivity between the medial prefrontal cortex and posterior DMN regions, alongside increased connectivity to the insular cortex proportional to pain intensity. Multiple DMN regions, especially the medial prefrontal cortex, exhibited increased high-frequency oscillations and decreased phase locking with parietal attention-processing regions. Both phase and frequency changes correlated with pain duration in osteoarthritis and chronic back pain patients. These findings suggest chronic pain reflects maladaptive neural dynamics across different pain types.
PLoS One
May 24, 2017
Jared R. Lindahl, Nathan E. Fisher, David J. Cooper et al.
468 citations
Meditation practices derived from Buddhism are widely used for health promotion, but their traditional sources also describe a broader range of effects. The Varieties of Contemplative Experience study used interviews with Western Buddhist practitioners and experts from Theravāda, Zen, and Tibetan traditions, plus a follow-up survey, to investigate underreported meditation-related experiences, especially those that are challenging, distressing, or impairing. Thematic analysis produced a taxonomy of 59 experiences across 7 domains: cognitive, perceptual, affective, somatic, conative, sense of self, and social. Interpretations and responses varied greatly, with valence ranging from very positive to very negative and distress from minimal to severe. The study identified 26 influencing factors across 4 domains: practitioner-level, practice-level, relationships, and health behaviors.
PLoS One
February 18, 2015
Fernanda Palhano-Fontes, Kátia C. Andrade, Luís Fernando Tófoli et al.
461 citations
Ayahuasca, a psychedelic brew used traditionally by Amazonian Amerindians, significantly reduces activity in key hubs of the Default Mode Network (DMN), specifically the Posterior Cingulate Cortex (PCC)/Precuneus and medial Prefrontal Cortex (mPFC), as measured by fMRI in ten experienced subjects. Functional connectivity within the PCC/Precuneus also decreased after intake, while the orthogonality between the DMN and task-positive network showed no significant change. These findings suggest that the altered state of consciousness induced by Ayahuasca, similar to effects from psilocybin, meditation, and sleep, involves modulation of DMN activity and connectivity.
PLoS One
February 17, 2012
Erich Studerus, Alex Gamma, Michael Kometer et al.
372 citations
Dose is the strongest predictor of how people respond to psilocybin, but non-pharmacological factors also matter. Among 409 administrations to 261 healthy volunteers, pleasant and mystical-type experiences were most strongly associated with high Absorption personality trait, emotional excitement and activity just before the drug, and few recent psychological problems. Unpleasant or anxious reactions were most strongly predicted by high Emotional Excitability, younger age, and undergoing a PET scan during the session. The findings confirm that personality, mood, and setting significantly shape psilocybin's effects, though dose remains the dominant factor.
PLoS One
August 19, 2013
Teri Suzanne Krebs, Pål-ørjan Johansen
338 citations
Lifetime use of classical serotonergic psychedelics (LSD, psilocybin, mescaline) is not associated with an increased risk of mental health problems. Analyzing data from over 130,000 US adults, researchers found no significant link between psychedelic use and higher rates of serious psychological distress, mental health treatment, or specific psychiatric disorders including panic disorder, major depression, mania, social phobia, and PTSD. In some cases, psychedelic use correlated with lower rates of mental health issues. The findings suggest that psychedelics are not an independent risk factor for mental health problems.
PLoS One
May 28, 2009
Chao‐gan Yan, Dongqiang Liu, Yong He et al.
315 citations
The default mode network (DMN), a set of brain regions active at rest, shows higher functional connectivity and stronger low-frequency fluctuations when people keep their eyes open (with or without a fixation point) than when they keep them closed. Although the overall connectivity patterns look similar across conditions, statistical comparisons reveal these differences. An order effect also appears: two eyes-closed sessions differ from each other. These findings suggest that having eyes open during rest may involve more non-specific visual gathering, evaluation, and mind wandering, and that researchers should carefully choose and order resting-state conditions in experimental designs.
PLoS One
August 8, 2012
José Carlos Bouso, Débora González, Sabela Fondevila et al.
313 citations
Regular ayahuasca use over one year is associated with better psychological well-being, mental health, and cognitive performance compared to active controls in non-ayahuasca religions. Users scored higher on Reward Dependence and Self-Transcendence, lower on Harm Avoidance and Self-Directedness, and showed significantly lower psychopathology scores. They performed better on tests of attention, executive function, and working memory (Stroop test, Wisconsin Card Sorting Test, Letter-Number Sequencing). Life attitude measures indicated greater spiritual orientation, purpose in life, and psychosocial well-being. No evidence of psychological maladjustment, mental health deterioration, or cognitive impairment emerged in the ayahuasca group.
PLoS One
February 17, 2015
Daniel Lim, Paul Condon, David Desteno
297 citations
After three weeks of mobile-app based mindfulness meditation training, people were more likely to give up their seat to a person on crutches displaying discomfort than those who completed cognitive skills training. Empathic accuracy—the ability to read others' emotions—did not improve with mindfulness practice, indicating that mindfulness-enhanced compassionate behavior does not rely on better emotional decoding. The experiment used an ecologically valid situation in a public waiting area to measure real compassionate responding.
PLoS One
January 1, 2010
Olivier Jacques Manzoni, Thomas S. Ray
295 citations
Psychedelic drugs are known to produce their mental effects primarily by activating 5-HT2A and 5-HT2C serotonin receptors. This reference work presents new data on the binding affinity of twenty-five psychedelic drugs at fifty-one receptors, transporters, and ion channels, along with literature data on ten additional drugs. A new method normalizes affinity data to allow direct comparison across drugs. The findings show that psychedelic drugs, particularly phenylalkylamines, are not as selective as commonly thought, interacting with forty-two of forty-nine broadly tested sites. The thirty-five drugs display diverse interaction patterns across eighteen different receptors, suggesting that this diversity may underlie the qualitative differences in their subjective effects.
PLoS One
September 24, 2012
Milan Scheidegger, Martin Walter, Mick Lehmann et al.
282 citations
Ketamine, an NMDA receptor antagonist that modulates glutamate signaling, rapidly reduces functional connectivity between the default mode network (DMN) and the dorsal nexus, a dorsal medial prefrontal cortex region linked to depression. In a randomized, placebo-controlled, double-blind, crossover resting-state fMRI study in healthy subjects, ketamine decreased connectivity from the DMN's posterior cingulate cortex hub to the dorsal nexus, pregenual anterior cingulate, and medioprefrontal cortex. This subacute modulation at 24 hours overlaps with ketamine's peak antidepressant efficacy in treatment-resistant depression, suggesting that targeting glutamatergic system-driven network dysconnectivity may underlie successful depression treatment.
PLoS One
June 10, 2016
Katharine N Thakkar, Heathman S Nichols, Lindsey G Mcintosh et al.
273 citations
People with schizophrenia experience a stronger rubber hand illusion (RHI) than matched controls, suggesting a more flexible body representation and weakened sense of self. In the RHI, watching a rubber hand being stroked while one's own unseen hand is stroked synchronously creates a sense of ownership over the rubber hand. In 24 schizophrenia patients and 21 controls, synchronous stimulation produced greater proprioceptive drift and stronger self-reported illusion in patients. Stimulation-dependent temperature changes occurred in both groups. One patient reported an out-of-body experience during the illusion, linking body disownership to psychotic experiences. The findings indicate abnormalities in temporo-parietal networks involved in body ownership, which may underlie delusions of passivity in schizophrenia.
PLoS One
April 23, 2019
Roland R. Griffiths, Ethan Hurwitz, Alan K. Davis et al.
249 citations
Experiences interpreted as personal encounters with God, whether occurring naturally or after taking psychedelic drugs, share striking similarities. In an online survey of over 4,200 people, those who had a nondrug encounter most often called it God, whereas those who had a psychedelic encounter most often called it Ultimate Reality. Regardless of origin, most participants vividly remembered the encounter as involving a conscious, benevolent, intelligent, sacred, eternal, and all-knowing presence. About half of all encounters met criteria for a complete mystical experience. More than two-thirds of self-identified atheists no longer identified as atheist afterward.
PLoS One
May 15, 2012
A Chiesa, A Chiesa, A Chiesa et al.
217 citations
Two experiments tested whether mindfulness practice reduces cognitive rigidity using a water jar task where initial problems required a complex formula, but later problems also allowed a simpler solution. Experienced meditators showed significantly less persistence with the complex formula compared to non-meditators in Experiment 1. In Experiment 2, non-meditators who completed an eight-session mindfulness program also had lower rigidity scores than a waiting list group. The authors conclude that mindfulness meditation reduces the tendency to be blinded by past experience, promoting more adaptive and flexible problem-solving.
PLoS One
June 30, 2015
Mahiko Konishi, Donald George McLaren, Haakon Engen et al.
210 citations
The default mode network (DMN) is more active when people make decisions based on stored information from a previous trial than when they respond to current perceptual input. Using fMRI, the study found increased BOLD activity in the medial prefrontal cortex and posterior cingulate cortex when individuals recalled the location of a shape from the prior trial, and decreased activity when they judged the current location. This challenges the view of the DMN as merely task-negative or emotion-sensitive. Instead, the DMN's core hubs enable cognition to be guided by internal representations rather than immediate sensory input, explaining its involvement in higher-order thought such as imagining the future or considering another's perspective.
PLoS One
September 25, 2012
Kieran C. R. Fox, Pierre Zakarauskas, Matthew L. Dixon et al.
194 citations
People who meditate for many years are better at accurately reporting their own internal bodily sensations than beginners. The study compared subjective reports of touch sensitivity in 20 body regions during a body-scanning meditation with objective measures of tactile sensitivity from prior research. Expert meditators (1–15,000 hours of experience) showed significantly greater introspective accuracy than novices, and overall meditation experience predicted individual accuracy. The findings suggest that long-term meditation practice may enhance the ability to accurately introspect.
PLoS One
January 1, 2014
Attila Szabo, Attila Kovács, Ede Frecska et al.
191 citations
The sigma-1 receptor, a protein found in the central nervous system and immune cells, can be activated by the psychedelic compounds N,N-dimethyltryptamine (NN-DMT) and 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) to dampen inflammatory responses in human immune cells. When human dendritic cells were exposed to inflammatory triggers along with these compounds, production of pro-inflammatory cytokines IL-1β, IL-6, TNFα, and chemokine IL-8 decreased, while the anti-inflammatory cytokine IL-10 increased. The compounds also reduced the cells' ability to activate inflammatory T-cells. This suggests dimethyltryptamines may act as endogenous regulators of inflammation and immune balance, pointing toward potential treatments for autoimmune and chronic inflammatory conditions.
PLoS One
September 2, 2008
Giuseppe Pagnoni, Milos Cekic, Ying Guo
189 citations
Zen meditation practitioners show a reduced duration of neural response in default-network brain regions during conceptual processing, suggesting that meditative training may help regulate the automatic cascade of semantic associations and spontaneous thought. Using fMRI and a lexical decision task, regular Zen practitioners and matched controls performed similarly behaviorally, but practitioners' brain activity linked to conceptual processing was briefer.
PLoS One
September 5, 2017
Ausiàs Cebolla, Marcelo Demarzo, Patricia Silveira Martins et al.
186 citations
About a quarter (25.4%) of meditation practitioners report unwanted effects (UEs), which are usually temporary and do not lead to stopping practice or seeking medical help. UEs are more common during focused attention meditation, when practicing alone for more than 20 minutes, and during individual practice; body awareness practices are associated with fewer UEs. The findings come from an online survey of 342 experienced meditators (at least two months of practice), mostly women from Spain with university education. The authors recommend using standardized questionnaires to better assess these effects in future research.
PLoS One
May 13, 2014
Krzysztof J. Gorgolewski, Daniel J. Lurie, Sebastian Urchs et al.
180 citations
Self-generated thoughts—such as daydreaming or mind-wandering—are linked to distinct patterns of spontaneous brain activity. Using the New York Cognition Questionnaire (NYC-Q) and resting-state fMRI data from the Nathan Kline Rockland Enhanced sample, researchers found that thoughts cluster into dimensions of content (future-related, past-related, positive, negative, social) and form (words, images, specificity). Individuals who reported more imagery showed greater low-frequency fluctuations in perigenual cingulate cortex, part of the default-mode network. Those with more future-oriented thoughts showed less homogeneous neural fluctuations in lateral occipital cortex, suggesting decoupling from sensory processing. Self-generated thought is a heterogeneous category, and studying its content helps understand brain dynamics.
PLoS One
September 30, 2009
Sam Harris, Jonas Kaplan, Ashley Curiel et al.
173 citations
Religious and nonreligious thinking activate different broad brain regions, but the neural difference between believing and disbelieving a statement is the same regardless of whether the content is religious or ordinary. This suggests that the brain's acceptance of statements as true or false operates through a content-independent mechanism, which may help explain how people come to accept any kind of statement as a valid description of the world.
PLoS One
October 24, 2023
Jules Evans, Oliver Robinson, Eirini K. Argyri et al.
166 citations
Long-term adverse experiences after psychedelic use can last weeks, months, or even years and are understudied. A mixed-method study of 608 participants who reported extended difficulties found the most common challenges were anxiety and fear, existential struggle, social disconnection, depersonalization, and derealization. For about one-third of participants, problems persisted over a year; for one-sixth, they lasted more than three years. Shorter difficulties were predicted by knowing the dose and drug type and by lower difficulty during the experience; a narrower range of difficulties was predicted by taking the drug in a guided setting. Implications for harm reduction are discussed.
PLoS One
August 15, 2012
Tatia M C Lee, Mei-Kei Leung, Wai-Kai Hou et al.
163 citations
Focused-attention meditation (FAM) and loving-kindness meditation (LKM) produce distinct patterns of brain activity during cognitive and emotional tasks. In a study of 44 male Chinese meditators, FAM practice was linked to expertise-related improvements in attention task performance and corresponding neural activation differences, while LKM did not carry over to attention performance. Both forms of meditation affected neural responses to affective pictures: during viewing of sad faces, FAM practitioners showed activation consistent with attention-related processing, whereas LKM experts showed responses more aligned with differentiating emotional contagion from compassion or emotional regulation. These findings provide the first report of distinct neural activity associated with these meditation forms during sustained attention and emotion processing.