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Anira Escrichs

Center for Brain and Cognition, Department of Information Technologies and Communications (DTIC), Universitat Pompeu Fabra, Barcelona, Spain.

8 papers in the library · 49 citations · publishing 2022-2026

Papers

Effects of classic psychedelic drugs on turbulent signatures in brain dynamics

Network Neuroscience January 1, 2022 Josephine Cruzat, Yonatan Sanz Perl, Anira Escrichs et al. 28 citations

Psychedelic drugs like LSD and psilocybin may treat neuropsychiatric disorders by dose-dependently altering the brain's functional hierarchy—the organization of neural activity across regions. Using a turbulence framework that measures local synchronization (vorticity) in both space and time, researchers found that both drugs produce consistent and distinct effects, particularly compressing the default mode network, a higher-level network. These findings support the hypothesis that psychedelics modulate the functional hierarchy and provide a quantitative comparison of how LSD and psilocybin change brain dynamics, with implications for therapeutic use.

ENIGMA-Meditation: Worldwide Consortium for Neuroscientific Investigations of Meditation Practices.

Biological psychiatry. Cognitive neuroscience and neuroimaging April 1, 2025 Saampras Ganesan, Fernando A Barrios, Ishaan Batta et al. 6 citations

Meditation practices, which have shown therapeutic benefits for conditions like depression, pain, addiction, and anxiety, have been studied with neuroimaging over the past decade. However, existing neuroscientific models are based on small, heterogeneous datasets, limiting generalizability and replicability. The ENIGMA-Meditation consortium is the first worldwide collaborative effort to conduct systematic meta- and mega-analyses of globally distributed neuroimaging data using standardized methods. This framework aims to improve statistical power and address multidomain heterogeneity in meditation practice types, experience, and experimental design. The consortium will generate rigorous neuroscientific insights into the mechanisms underlying meditation's therapeutic effects on psychological and cognitive attributes.

Long-term effects of psilocybin on dynamic and effectivity connectivity of fronto-striatal-thalamic circuits

bioRxiv (Cold Spring Harbor Laboratory) November 7, 2024 Lorenzo Pasquini, Jakub Vohryzek, Anira Escrichs et al. 4 citations preprint

Psilocybin induces fast and sustained improvements in mental well-being, yet its long-term mechanisms are not fully understood. Four weeks after a full dose, fronto-striatal-thalamic (FST) circuitry—involved in goal-directed behavior and motivation—shows increased dynamic activity and flexibility in healthy volunteers. Computational modeling indicates that reduced structural constraints on functional dynamics cause this increased flexibility. Long-term changes include increased bottom-up and reduced top-down information flow, mediated by serotonergic (5-HT2A) and dopaminergic (D2) receptor systems. This functional re-organization of FST circuits may represent a common mechanism underlying clinical improvements across neuropsychiatric disorders such as substance abuse, major depression, and anorexia.

Inducing a meditative state by artificial perturbations: A mechanistic understanding of brain dynamics underlying meditation.

Network neuroscience (Cambridge, Mass.) January 1, 2024 Paulina Clara Dagnino, Javier A Galadí, Estela Càmara et al. 4 citations

Meditation produces distinct whole-brain dynamics compared to rest. Using fMRI data from expert meditators and controls, the authors defined probabilistic metastable substates (PMS) for each condition, capturing different probabilities of dynamic brain patterns. They then fit a whole-brain model to these substates and performed in silico perturbations to simulate transitions between resting-state and meditation. The results show that localized artificial perturbations can induce such transitions, and the sensitivity of different brain areas to perturbation varies. This mechanistic framework clarifies how meditation alters brain dynamics and suggests potential applications for health and therapy.

Nonequilibrium brain dynamics elicited as the origin of perturbative complexity.

PLoS computational biology June 6, 2025 Wiep Stikvoort, Eider Pérez-Ordoyo, Iván Mindlin et al. 3 citations

A person's level of consciousness can be assessed by how the brain reacts to stimulation, but this study shows that the brain's unperturbed activity already contains that information. Using personalized whole-brain models fitted to resting-state fMRI data from people in altered states of consciousness (deep sleep, disorders of consciousness), the researchers measured the brain's out-of-equilibrium dynamics—specifically, the asymmetry of effective connections and time irreversibility. They found that states with lower arousal or awareness had less asymmetric connectivity, less irreversibility, and lower complexity in simulated responses compared to controls. The asymmetry in connections drives the nonequilibrium state and, in turn, the differences in complexity.

ENIGMA-Meditation: Worldwide consortium for neuroscientific investigations of meditation practices

April 8, 2024 Saampras Ganesan, Aki Tsuchiyagaito, Greg J. Siegle et al. 2 citations preprint

Meditation practices, which have been adapted into manualized interventions for conditions like depression, pain, addiction, and anxiety, show therapeutic promise, but their neuroscientific basis remains unclear. Current neuroimaging studies rely on small, heterogeneous datasets that vary in practice types, participant experience, clinical targets, and imaging methods, limiting generalizability and replicability. To address this, the ENIGMA-Meditation consortium was formed as a global collaboration to conduct systematic meta- and mega-analyses of distributed neuroimaging data using standardized methods. This framework aims to improve statistical power and rigorously characterize the neural mechanisms underlying meditation's effects on psychological and cognitive attributes, advancing the field of contemplative neuroscience.

Distinct brain responses to psilocybin and escitalopram in depression captured by the Fluctuation-Dissipation Theorem

bioRxiv (Cold Spring Harbor Laboratory) June 16, 2026 Paulina Clara Dagnino, Irene Acero-Pousa, Gorka Zamora‐lópez et al. 1 citation

Psilocybin and the conventional antidepressant escitalopram produce opposite changes in the brain's hierarchical non-equilibrium dynamics when treating major depressive disorder. Using resting-state fMRI before and after treatment, researchers built whole-brain models and measured how much each patient's brain activity deviated from the fluctuation-dissipation theorem. Baseline measures distinguished treatment responders from non-responders within each group. The deviation from the fluctuation-dissipation theorem may serve as a marker to differentiate the brain effects of psilocybin and escitalopram, contributing to understanding how these treatments work for depression.

Inducing a meditative state by artificial perturbations: A causal mechanistic understanding of brain dynamics underlying meditation

bioRxiv Preprint Server July 27, 2023 Paulina Clara Dagnino, Javier A. Galadí, Estela Càmara et al. 1 citation preprint

Meditation produces distinct whole-brain dynamics compared to rest, particularly in the triple-network model (executive control, salience, and default-mode networks). Using a causal mechanistic framework, researchers defined probabilistic metastable substates from dynamic brain patterns and adjusted a whole-brain model of the resting state to simulate transitions to meditation. They successfully induced the meditative state through localized artificial perturbations, primarily shifting areas in the somatomotor and dorsal attention networks. The work suggests meditation can be studied as a practice for health and as a potential therapy for brain disorders.