Frontiers in Physiology
February 11, 2020
Thomas A. W. Bolton, Diana Wotruba, Roman Buechler et al.
83 citations
Altered coordination between the default mode, central executive, and salience networks is linked to schizophrenia, but its role in earlier at-risk stages is unclear. Using dynamic functional connectivity and co-activation pattern analysis of resting-state fMRI, this study examined right anterior insula interactions in 19 individuals with subthreshold delusions and hallucinations (UHR), 28 with basic symptoms of self-experienced subclinical disturbances (BS), and 29 healthy controls. The right anterior insula governs transitions from the central executive to default mode network, which become dysfunctional before psychosis onset, especially when attenuated psychotic symptoms emerge.
Frontiers in Physiology
January 23, 2023
Aravind Natarajan
36 citations
Heart rate variability (HRV) metrics commonly used in biofeedback, such as RMSSD, preferentially weight higher-frequency heart rate fluctuations, making them unsuitable for tracking slow, mindful breathing. A new metric called the autonomic balance index (ABI) uses Respiratory Sinus Arrhythmia to quantify the fraction of HRV contributed by the parasympathetic nervous system. Applied to data from two meditation techniques, ABI was significantly elevated during mindful breathing, indicating it is a good signal for biofeedback during meditation sessions.
Frontiers in Physiology
September 2, 2022
Charles Verdonk, Marion Trousselard, Takfarinas Medani et al.
Body awareness is thought to be a cognitive mechanism of mindfulness, but neuroscience evidence is limited. Postural control during quiet standing relies on body cues, especially with eyes closed. Postural signals were recorded from 156 healthy participants standing quietly with eyes closed and eyes open. Each participant completed the Freiburg Mindfulness Inventory. Machine learning models were trained to estimate mindfulness scores and classify participants as mindful or non-mindful from their postural signals. Models using eyes-closed data performed much better than those using eyes-open data. These findings provide the first physiological evidence supporting the hypothesis that mindfulness involves enhanced body awareness.
Frontiers in Physiology
January 1, 2018
Brian Key, Deborah J Brown
Subjective sensory experience, or what it feels like, arises in the cerebral cortex of humans and mammals. While humans verbally report their experiences, other species' awareness is inferred from behavior. Cephalopods have been considered sentient due to complex behavior, but analyzing avoidance learning and brain lesion studies shows no evidence they feel pain. Anthropometric assumptions become questionable with greater phylogenetic distance. Understanding invertebrate sentience requires defining the neural circuits for subjective awareness, which depends on observer neural networks that introspect sensory processing and create predictive internal models. An algorithm using parallel observer networks generates multiple awareness levels; human cortical regions match its predicted circuitry for pain awareness, but cephalopod brains lack the necessary neural architecture. Thus, no compelling evidence indicates cephalopods feel pain.
Frontiers in Physiology
July 4, 2016
Anirban eBhaduri, Dipak eGhosh
Cardiac dynamics during meditation show measurable changes in complexity when analyzed with two non-linear techniques: multi-fractal detrended fluctuation analysis and visibility network analysis. Using instantaneous heart rate data from subjects performing Kundalini Yoga and Chi meditation, the study found consistent differences in quantitative parameters between the two analysis methods. These results suggest that meditation alters the fractal and network properties of heart rate variability, providing preliminary evidence that such techniques can serve as objective measures of the physiological impact of meditation.
Frontiers in Physiology
January 1, 2011
Stephanie L Hawkins
William James, the American psychologist and philosopher, sought a naturalistic understanding of consciousness through unorthodox methods including experiments with nitrous oxide and hallucinogenic drugs, as well as investigations of spiritualist mediums. His training in brain physiology and experimental psychology could not fully account for the "hard problems" of consciousness. James developed a "radically empiricist" philosophy that privileged discontinuity and plurality, arguing against philosophical monism and scientific materialism. He was convinced that naturalistic explanations existed for transcendent experiences associated with hysteria, genius, and religious ecstasy. His "transmission theory" of consciousness, ideas on "knowing of things together," and concept of "the compounding of consciousness" suggest he was working toward a "distributive model" of consciousness as awareness interacting dynamically within its environment.