Progress in Brain Research
January 1, 2019
Zoran Josipovic
A non-representational reflexivity theory is proposed to explain the nature of consciousness-as-such, which is distinct from the contents of awareness and levels of arousal. The theory posits that consciousness-as-such is a non-conceptual, nondual awareness whose essential property is non-representational reflexivity, making it phenomenologically, cognitively, and neurobiologically unique and irreducible to any contents, functions, or states, including an indeterminate substrate. The precuneus network hypothesis for nondual awareness is discussed in relation to this reflexivity and other neural correlate hypotheses.
Progress in Brain Research
January 1, 2024
Fabio Marson, Revital Naor-Ziv, Patrizio Paoletti et al.
Empathy, the ability to infer others' emotions, is linked to bodily sensations from the autonomic nervous system. A survey of 581 participants found that people who meditate score higher on empathy than non-meditators. Lower autonomic reactivity in organs above the diaphragm was associated with higher empathy. Among participants with high autonomic reactivity, empathy was positively linked to interoceptive components of abstract concepts. The results suggest that meditation and low autonomic reactivity relate to empathy, possibly by downregulating autonomic responses.
Progress in Brain Research
January 1, 2023
Kenji Hashimoto
Neuroinflammation is central to major depressive disorder (MDD) and treatment-resistant depression (TRD), with patients showing higher inflammatory biomarkers. The gut-microbiota-brain axis, mediated by the vagus nerve, contributes to neuroinflammation. Fecal microbiota transplantation (FMT) from depressed humans or rodents induces depression-like behaviors and systemic inflammation in rodents, effects blocked by subdiaphragmatic vagotomy. Vagotomy also blocks antidepressant effects of serotonergic drugs. The antidepressant arketamine may restore altered gut microbiota in depressed rodents. This chapter reviews the vagus nerve-dependent gut-microbiota-brain axis in depression and discusses FMT, vagus nerve stimulation, and arketamine as potential TRD treatments.
Progress in Brain Research
January 1, 2023
Loredana Verdone, Fabio Marson, Micaela Caserta et al.
A movement meditation called Quadrato Motor Training (QMT) reduced levels of the proinflammatory cytokine interleukin-1beta (IL-1β) and increased creativity in healthy adults. Thirty participants were divided into a QMT group that practiced for two months and a passive control group. Salivary IL-1β protein decreased and performance on the Alternate Uses Task, a measure of creativity, improved in the QMT group compared with controls. The findings suggest that non-pharmacological mind-body practices can reduce inflammation and support cognitive function.
Progress in Brain Research
January 1, 2019
Amrendra Singh, V. S. Chandrasekhar Pammi, A. Guleria et al.
Long-term concentrative meditation practice alters visual awareness by strengthening attentional control. Using negative color afterimages in a functional MRI study, activity increased in right inferior occipital and inferior frontal cortex, suggesting these brain regions are key to how attention modulates conscious visual experience. The findings indicate that meditation may change the link between attention and conscious experience.
Progress in Brain Research
January 1, 2019
Marieke K. van Vugt, Amir Moye, Joshua Pollock et al.
Analytical meditation and monastic debate, contemplative practices central to Tibetan Buddhist monastic training at Sera Jey Monastic University, have been largely unexplored in Western science. Based on discussions with teachers and senior students and preliminary experiments, the authors outline a theory of the psychological mechanisms underlying this highly physical form of debate. They propose that successful debating requires reasoning, critical thinking, attentional focus, working memory, emotion regulation, confidence in reasoning, and social connectedness. The cumulative hours of debate practice over 20+ years of monastic training likely cultivate these skills. Scientific research is needed to test these hypotheses and determine debate's role in psychological wellbeing and educational achievement.
Progress in Brain Research
January 1, 2019
Ratna Jyothi Kakumanu, Ajay Kumar Nair, Arun Sasidharan et al.
Long-term Vipassana meditation practice, both in duration and quality, is linked to graded differences in brain activity during a cognitive task. After an hour of meditation, three groups of practitioners—novices, seniors, and teachers—performed a gamified oddball task while EEG was recorded. All groups performed well and showed similar overall brain-wave patterns, but more experienced meditators exhibited reduced theta synchrony, enhanced alpha desynchronization, and lesser theta-alpha coherence. Teachers differed most from novices, with seniors forming an intermediate group. The findings suggest that both the quantity and quality of meditation influence EEG dynamics during cognitive processing, and that meditating before a task can amplify these state-trait effects.
Progress in Brain Research
January 1, 2019
Aviva Berkovich-Ohana, Patricia A. Jennings, Shiri Lavy
Mindfulness meditation alters the neural networks underlying self-awareness, which may help teachers manage stress and create supportive learning environments. This review connects insights from contemplative neuroscience with education, proposing that changes in self-awareness are a core mechanism linking mindfulness practice to improved teacher well-being and educational outcomes. The authors argue that incorporating these neuroscientific findings into contemplative pedagogy has significant implications for educational policy.
Progress in Brain Research
January 1, 2019
A. Raffone, L. Marzetti, C. del Gratta et al.
A unified Brain Theory of Meditation (BTM) is proposed, grounded in the roles of the central executive, salience, and default mode networks and the brain's energetic limitation that only about 1% of cortical neurons can be concurrently active. The theory suggests distinct mechanisms for different meditation forms: down-regulation of brain network activities in focused attention meditation, gating and tuning of network coupling in open monitoring meditation, and state-related up-regulation in compassion and loving kindness meditation. It also advances a leftward asymmetry in top-down regulation and enhanced inter-hemispheric integration in meditation states and traits, with implications for understanding conscious access. Meditation provides a meta-function for efficient brain resource allocation, related to mindfulness.
Progress in Brain Research
January 1, 2018
Tanya Calvey, Fleur M Howells
Psychedelic drugs produce acute experiences and long-lasting neurobiological changes by activating several neuromodulatory systems. Classic and atypical psychedelics are grouped by neuro-receptor affinities, each with distinct treatment potentials. Brain imaging studies show discrepancies between neural activity and hemodynamic needs, requiring further investigation to understand brain 'state' changes. The psychedelic brain state is often compared to acute psychosis, and animal models and human imaging studies are reviewed to contrast the two. Psychedelics have anti-amnesic effects and can make unconscious material conscious through brain state changes, with growing evidence for epigenetic mechanisms supporting traditional therapeutic use for healing ancestral trauma.
Progress in Brain Research
January 1, 2018
K. Murnane
Human research with psychedelics is producing groundbreaking discoveries, modifying enduring personality traits and reducing anxiety, depression, and substance dependence in small but well-designed clinical studies. Psychedelics are advancing through pharmaceutical regulatory systems, and neuroimaging has related their effects to select brain networks. However, preclinical studies have lagged behind this renaissance. Preclinical research offers tight control of experimental parameters, subjects with documented drug histories, and the ability to elucidate signaling cascades and conduct invasive mechanistic studies. Safety pharmacology, biomarkers, and pharmacokinetics can be assessed in disease models to advance psychedelics toward clinical practice. This chapter argues that new preclinical studies would benefit the field.
Progress in Brain Research
January 1, 2009
A. Raffone, N. Srinivasan
A theoretical framework for the neural correlates of consciousness (NCC) is proposed, integrating endogenous attention, access consciousness, phenomenal awareness, metacognitive consciousness, and a non-referential unified consciousness. The adaptive workspace hypothesis builds on the global workspace model, emphasizing transient resonant neurodynamics and prefrontal cortex function, particularly the anterior prefrontal cortex. Transient dynamic links within an adaptive coding net, involving ongoing intrinsic and long-range signal exchanges between prefrontal cortex and the rest of the brain, flexibly regulate the interplay among these processes. Moment-to-moment modulation by body and environment states, along with brain regions associated with interoceptive and exteroceptive self-awareness (as highlighted in open monitoring meditation), play a key modulatory role in adaptive workspace transitions.
Progress in Brain Research
January 1, 2008
Rahul Banerjee
A classical Indian model of consciousness from the Abhidhamma, part of the Pali Canon, is reviewed. Based on observations during advanced vipassana meditation, the model culminates in 24 'Bridging Relations' that causally link the stream of consciousness, its contents, and associated physical events. This first-person approach may offer useful ideas for future research.
Progress in Brain Research
January 1, 2008
Dhananjay V Chavan
Vipassana, a first-person method taught by the Buddha for examining conscious experience, is most thoroughly detailed in the Satipatthana Sutta. This chapter reviews salient features of Vipassana practice as described in that text. The authors suggest that formal first-person methods may become necessary for tracking internal subjective states in the scientific study of consciousness, and that reviewing classical methods could guide further research.
Progress in Brain Research
January 1, 2005
Igor Aleksander
A review of work from several laboratories on modeling consciousness, ranging from functional models that prioritize behavior to material models grounded in brain anatomy. Functional approaches include applications for job-finding where a machine must be indistinguishable from a conscious human, using global workspace theories. Material approaches model attentional brain mechanisms and biochemical processes in children. The chapter distinguishes between attempts to model phenomenology (synthetic phenomenology) and those that do not. Studying consciousness through machine design is expected to produce a computational language for expressing consciousness and computational methods for building flexible, competent machinery.
Progress in Brain Research
January 1, 2005
Bernard J. Baars
Global workspace theory proposes that conscious cognition involves widespread brain activity, especially in frontoparietal and medial temporal regions, while unconscious processing is limited to local areas. The theory emerged from cognitive architecture research and generates predictions for conscious aspects of perception, emotion, learning, and voluntary control. Brain imaging studies show that conscious tasks produce broad cortical activation, whereas unconscious conditions activate only local regions such as visual projection areas. Frontoparietal hypometabolism is also observed in unconscious states including deep sleep, coma, vegetative states, epileptic loss of consciousness, and general anesthesia. These findings support the global workspace hypothesis, which is endorsed by many scientists and philosophers.
Progress in Brain Research
January 1, 2005
Silvia Bünning, Olaf Blanke
Out-of-body experiences (OBEs) involve feeling awake while perceiving one's body and surroundings from a location outside the physical body, characterized by disembodiment, an elevated and distanced visuo-spatial perspective, and seeing one's own body (autoscopy). OBEs have been reported across cultures throughout history. This review examines classic triggers such as sleep, drug use, and general anesthesia, alongside recent neurological and neurocognitive findings. The evidence suggests OBEs result from a functional disintegration of lower-level multisensory processing and abnormal higher-level self-processing at the temporo-parietal junction. Investigating interactions between these mechanisms, using neuroimaging and behavioral techniques, may advance understanding of corporal awareness and self-consciousness.