NeuroImage
January 18, 2017
Hannah Scheibner, Carsten Bogler, Tobias Gleich et al.
136 citations
Focused attention meditation is linked to reduced activity in the default mode network (DMN) compared to mind-wandering, regardless of whether attention is directed internally or externally. In twenty meditation-naïve adults who practiced mindfulness of sound and breathing for four days, brain scans showed that during mindful attention, regions like the medial prefrontal cortex, posterior cingulate cortex, and left temporoparietal junction were less active than during mind-wandering. Deactivation in the posterior cingulate cortex was stronger during internal attention than external attention. Refocusing after mind-wandering engaged the left inferior frontal gyrus. These findings suggest that mindful attention, not the focus of attention, drives DMN reduction.
Journal of Psychopharmacology
March 4, 2021
Tomislav Majić, Meike Sauter, Felix Bermpohl et al.
14 citations
An online survey of 386 mostly well-educated individuals who had used Kambô, the secretion of the Giant Maki Frog, found that motivations included general healing, detoxification, and spiritual growth. Acute effects involved severe physical reactions and mild psychoactive experiences, with 41.97% reporting a feeling of connection to the frog's spirit. Most participants (87.31%) reported increased well-being or life satisfaction, and 64.26% considered Kambô of high spiritual significance. Few reported lasting physical (2.85%) or mental (1.81%) health problems attributed to Kambô. The authors note that further research is needed to understand how setting and expectations influence reported effects.
Scientific Reports
December 9, 2020
Timo Torsten Schmidt, Simon Reiche, Caroline L. C. Hage et al.
12 citations
Kambô, the secretion of the Amazonian Giant Leaf Frog, contains many bioactive peptides and was traditionally used by indigenous Amazonian communities as medicine to improve hunting. In Western urban healing circles, its use has spread over the past 20 years. This retrospective study assessed psychological effects in 22 anonymous users using standardized questionnaires for altered states of consciousness. Acute effects were mild to moderate, with no psychedelic-type perceptual or thinking distortions. Persisting effects were predominantly positive, with high scores on personal and spiritual significance.
Progress in neuro-psychopharmacology & biological psychiatry
April 2, 2025
Simon Reiche, Tim Hirschfeld, Anna Lena Gröticke et al.
5 citations
People who have used psychedelics such as psilocybin, LSD, or ayahuasca a mild to moderate number of times over their lives show broadly equivalent neuropsychological performance to non-users, but with a modest advantage in executive functions, particularly cognitive flexibility as measured by the Wisconsin Card Sorting Test (WCST). In matched-pair analyses, users performed better on the WCST, and dose-response analyses within the user group found that greater lifetime use was positively associated with fewer total errors, perseverative responses, perseverative errors, non-perseverative errors, and more conceptual level responses. The study did not find any negative associations between sporadic psychedelic use and cognition.
bioRxiv (Cold Spring Harbor Laboratory)
July 24, 2020
Timo Torsten Schmidt, Simon Reiche, Caroline L. C. Hage et al.
preprint
Kambô, the secretion of the Giant Leaf Frog (Phyllomedusa bicolor), is ritually used by Amazonian ethnicities against bad luck in hunting and has spread to Western urban centers, often alongside ayahuasca. A retrospective study of 22 anonymous users (mean age 39 years, 45.5% female) assessed acute and subacute psychological effects with standardized questionnaires. Acutely, participants reported mild to moderate psychological effects without psychedelic-type perceptual or thinking distortions. Persisting effects were predominantly positive and pleasant, with surprisingly high personal and spiritual significance. Subacute and long-term effects overlapped with the 'afterglow' phenomena following serotonergic psychedelics.