Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2024
Balázs Szigeti, Boris D Heifets
62 citations
Clinical trials of psychedelics such as psilocybin, LSD, and DMT have challenged how nondrug factors like participant expectations are measured and controlled in mental health research. Higher doses of these psychoactive substances make it harder to conceal treatment conditions in double-blind, placebo-controlled designs. Growing public enthusiasm for psychedelic therapy raises questions about whether trial results are biased by positive expectancy. This review covers key concepts of expectancy and its measurement, examines expectancy effects reported in modern microdose and macrodose trials, and considers expectancy as a physiological process that can be independent of or interact with drug effects. Expectancy can be harnessed to improve outcomes and managed to enhance trial rigor.
Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2024
Robin J Murphy, Suresh Muthukumaraswamy, Harriet de Wit
31 citations
Taking regular low doses of psychedelic drugs (microdosing) has drawn attention for potential psychotherapeutic effects, but controlled studies have lagged. A review of 14 rigorous double-blind placebo-controlled studies using investigator-supplied lysergic acid diethylamide (LSD) at 5-20 micrograms found that acute microdoses dose-dependently altered blood pressure, sleep, neural connectivity, social cognition, mood, and perception of pain and time. Perceptible drug effects occurred at 10-20 micrograms but not 5 micrograms. No serious adverse effects were reported. Repeated doses did not alter mood or cognition on any measures. Low doses of LSD appear safe and produce acute behavioral and neural effects in healthy adults, warranting further study in patient samples and with other psychedelics.
Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2024
Mark A. Geyer
30 citations
Classic serotonergic psychedelics like LSD, psilocybin, and mescaline profoundly alter mood, thought, perception, and self-experience. Their use spans cultural rituals and healing practices. Modern research into their effects has been closely linked to studies of the neurotransmitter serotonin, with early hypotheses supported by animal and human studies. While early attempts to use psychedelics as psychotomimetics to model psychosis had limited success, recent work explores them as psychotherapeutic agents. Even one or two treatments have produced robust and sustained reductions in clinical symptoms across psychiatric disorders, sparking renewed interest in their mechanisms.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Vaibhav Tripathi, Ishaan Batta, Andre Zamani et al.
23 citations
The default mode network (DMN) is linked to self-referential thinking, memory, and goal-directed cognition. Its functional connectivity with frontoparietal networks involved in attention and executive control may indicate cognitive health. This review examines DMN connectivity metrics as potential biomarkers across states like attention, mind wandering, and meditation, and in conditions such as Alzheimer's disease, Parkinson's disease, depression, and ADHD. It also addresses the reliability of network estimation and offers recommendations for using functional connectivity measures as biomarkers of cognitive health.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Antoine Lutz, Oussama Abdoun, Yair Dor-Ziderman et al.
18 citations
The neurophenomenology research program, pioneered by Varela, rigorously examines subjective experience using first-person methodologies inspired by phenomenology and contemplative practices. This review explores recent advancements, particularly their application to meditation practices and potential clinical translations. It examines innovative multidimensional phenomenological assessment tools designed to capture subtle, dynamic shifts in experiential content and structures of consciousness during meditation, shedding light on mechanisms and trajectories of meditation practice.
Biological psychiatry. Cognitive neuroscience and neuroimaging
July 1, 2023
Stefano Delli Pizzi, Piero Chiacchiaretta, Carlo Sestieri et al.
18 citations
LSD alters brain functional connectivity and local signal amplitude in opposite directions depending on the type of serotonin receptor involved. In healthy volunteers, LSD increased activity and connectivity in cortical regions of the default mode and attention networks, which have high densities of 5-HT2A receptors; these changes correlated with visual hallucinations. Conversely, LSD decreased activity and connectivity in limbic areas rich in 5-HT1A receptors. The spatial patterns of these functional changes overlapped with the distribution of the two serotonin receptor subtypes, suggesting distinct receptor-mediated mechanisms underlie LSD's reorganization of brain networks.
Biological psychiatry. Cognitive neuroscience and neuroimaging
July 1, 2024
Sepehr Mortaheb, Larry D Fort, Natasha L Mason et al.
15 citations
Psilocybin produces profound alterations in both brain connectivity and subjective experience. In a randomized study, healthy volunteers received psilocybin or placebo and underwent ultrahigh field 7T fMRI scanning during the peak drug effect. Psilocybin caused widespread increases in averaged brain functional connectivity and a recurrent hyperconnected brain pattern with low blood oxygen level-dependent signal amplitude, suggesting heightened cortical arousal. This hyperconnected pattern was linked to feelings of oceanic boundlessness and visionary restructuralization. The brain's tendency to enter this hyperconnected-hyperarousal state may underlie the variant mental associations characteristic of the psychedelic experience.
Biological psychiatry. Cognitive neuroscience and neuroimaging
August 1, 2024
Xuefeng Xu, Xuefeng Ma, Haosen Ni et al.
14 citations
Mindfulness meditation reduced addiction severity and game craving in people with internet gaming disorder more effectively than progressive muscle relaxation. After one month of training, functional connectivity between the executive control network and both the default mode network and reward-related brain regions increased. These connectivity changes correlated negatively with dopamine and acetylcholine transporters and positively with serotonin and GABA receptors. The findings suggest mindfulness meditation enhances top-down control over cravings by altering brain network interactions.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Ruchika S Prakash, Anita Shankar, Vaibhav Tripathi et al.
13 citations
Network neuroscience examines brain organization by mapping connections between its elements. This review describes how mindfulness meditation may alter structural and functional brain networks. Although evidence is preliminary, studies suggest mindfulness shifts connector hubs—the anterior cingulate cortex, thalamus, and mid-insula—and reduces intraconnectivity within the default mode network. Global connectivity findings are mixed. The authors call for rigorous study designs, open science, and diverse samples to better understand mindfulness's impact on brain networks.
Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2024
Mihai Avram, Felix Müller, Katrin H Preller et al.
13 citations
In a double-blind, placebo-controlled, crossover study with 25 healthy participants, LSD, MDMA, and d-amphetamine all increased effective connectivity from the thalamus to specific unimodal cortices while reducing the influence of those cortices back onto the thalamus, indicating stronger bottom-up and weaker top-down information flow. For transmodal cortices, including parts of the salience network, amphetamines showed opposite effects. LSD uniquely increased effective connectivity from the thalamus to both unimodal and transmodal cortices, suggesting a breakdown in the hierarchical organization of brain activity. These findings refine models of how psychedelics alter brain connectivity.
Biological psychiatry. Cognitive neuroscience and neuroimaging
January 18, 2025
Brian J Roach, Judith M Ford, Spero Nicholas et al.
7 citations
Abnormalities in the 40-Hz auditory steady-state response (ASSR), a measure of gamma-band brain activity, appear in schizophrenia and in animal models with reduced NMDA receptor function. This study compared 40-Hz ASSR deficits in schizophrenia patients to those induced by ketamine (an NMDA receptor antagonist) in healthy participants. Schizophrenia patients showed increased prestimulus broadband gamma power and reduced evoked power, total power, and phase-locking factor, replicating prior work, but no phase delay. Ketamine similarly increased prestimulus gamma power and reduced evoked power, total power, and phase-locking factor, while also advancing the ASSR phase. Direct comparison revealed significant differences only in phase, suggesting NMDA receptor hypofunction contributes to gamma oscillation abnormalities in schizophrenia.
Biological psychiatry. Cognitive neuroscience and neuroimaging
October 1, 2024
Manoj K Doss, Pablo Mallaroni, Natasha L Mason et al.
7 citations
Two psychedelics, psilocybin and 2C-B, impair the encoding of detailed recollections and distort feelings of familiarity for emotional memories. In a double-blind, placebo-controlled study with 20 participants, both drugs reduced estimates of recollection and familiarity the next day, but increased false alarms based on familiarity, especially for negative and positive images. The drugs also tended to impair metamemory for negative and neutral memories while enhancing it for positive ones, though these effects were less reliable. The similar pattern across both substances suggests a shared neurocognitive mechanism among psychedelics that may underlie other phenomena.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Joseph C C Chen, David A Ziegler
6 citations
Mindfulness meditation can improve well-being, but people often struggle with adherence, session quality, or dosage. Closed-loop systems and real-time neurofeedback—using signals from fMRI or EEG—may help support mindfulness performance and engagement. This review describes how neurofeedback signals such as fMRI activity in the posterior cingulate cortex, default mode network, central executive network, and salience network, as well as EEG alpha, theta, and gamma bands, have been used to provide subjective correlates of mindfulness states. Past work has focused on aligning interventions with the subjective meditation experience. Future research should use control conditions like mindfulness only or sham neurofeedback to quantify the effects of closed-loop and neurofeedback-guided meditation on cognition and well-being.
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.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Brian Lord, John J B Allen, Shinzen Young et al.
4 citations
Mindfulness benefits mental health and cognition through a combination of top-down attention and bottom-up emotional processes, with equanimity—the ability to maintain an open, nonreactive attitude toward all experiences—driving many of these benefits. Noninvasive brain stimulation (NIBS) can alter neural circuits involved in mindfulness, but most studies have focused on cognitive control rather than equanimity. Preliminary findings using focused ultrasound on the posterior cingulate cortex suggest NIBS can directly facilitate equanimity by inhibiting self-referential processing in the default mode network, promoting a more present-centered state. Future research should integrate NIBS with mindfulness training, targeting equanimity to advance contemplative neuroscience and develop individualized wellness interventions.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Yanli Lin, Daniel A Atad, Anthony P Zanesco
4 citations
EEG remains a powerful and non-obsolete tool for studying the neural basis of mindfulness. The review outlines EEG's unique advantages for experimental design, highlights new analytic approaches and translational paradigms, and gives examples from the authors' work and the broader literature. It argues that EEG can still spark new insights in both basic science and clinical applications of mindfulness, and encourages investigators to fully use its capabilities to advance contemplative neuroscience.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Clemens C C Bauer, Daniel A Atad, Norman Farb et al.
3 citations
The observer effect—the idea that observing a phenomenon changes it—is often seen as a problem to control, but this paper argues it should be actively studied and used. Mindfulness practices, which cultivate present-moment, nonjudgmental awareness, are proposed as a way to account for and intentionally harness this effect. In research, mindfulness training may help participants give more precise self-reports by reducing reactive biases. Evidence suggests mindfulness improves interoceptive awareness and reduces automatic judgment, potentially increasing measurement validity. Clinically, therapies often aim to make unconscious patterns observable; mindfulness cultivates meta-awareness, allowing individuals to observe cravings or anxiety without reactivity, facilitating psychological change. The paper proposes developing an observer-effect index to code observer influence.
Biological psychiatry. Cognitive neuroscience and neuroimaging
April 1, 2025
Jarrod A Lewis-Peacock, Tor D Wager, Todd S Braver
2 citations
Using multivariate predictive models to identify brain mechanisms underlying the benefits of mindfulness meditation is a promising methodology that departs from conventional brain mapping. Two strategies—state induction and neuromarker identification—are highlighted, with examples distinguishing focused attention from mind wandering and showing effects of mindfulness interventions on somatic pain and drug-related cravings. Future research must address tradeoffs between personalized and population-based predictive modeling.
Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2026
Zachary Anderson, Matthew Gunn, Emily Jones et al.
A moderate oral dose of THC (7.5 mg) reduced resting-state functional connectivity within several brain networks, including corticostriatal circuits and networks involved in sensory processing, interoception, and spatial reasoning, in 33 healthy occasional young adult cannabis users. THC also decreased connectivity between two specific networks: one involving the anterior cingulate cortex and dorsal insula, and another involving the ventral insula and lingual gyrus. These connectivity changes were not related to subjective drug effects or recent cannabis use. The findings indicate that even a single moderate THC dose broadly disrupts intrinsic brain network connectivity.
Biological psychiatry. Cognitive neuroscience and neuroimaging
January 13, 2026
Caitlin Baten, Gladys Zamora, Amanda M Klassen et al.
A meta-analysis of 135 fMRI studies involving 6,391 participants found that youth and adults with major depressive disorder (MDD) show different patterns of brain activation during tasks. Compared to adults with MDD, youth with MDD had distinct activation differences in the subgenual anterior cingulate cortex (sgACC) and dorsolateral prefrontal cortex (dlPFC). After controlling for illness duration, youth showed less activation than adults with shorter-duration MDD in regions like the sgACC. Among adults, those with longer-duration MDD showed less activation in the dlPFC compared to those with shorter-duration MDD. These results suggest that both age and length of illness matter for understanding brain changes in depression.