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Brian N. Mathur

University of Maryland, Baltimore

2 papers in the library · 60 citations · publishing 2021-2025

Papers

Psychedelics and Consciousness: Distinctions, Demarcations, and Opportunities

The International Journal of Neuropsychopharmacology May 10, 2021 Natalie Gukasyan, David B. Yaden, Matthew W. Johnson et al. 56 citations

Psychedelic substances produce unusual changes in conscious experience, leading some to propose they offer unique insights into consciousness. However, psychedelics are unlikely to provide information relevant to the "hard problem of consciousness," which involves explaining how first-person experience emerges. Instead, they bear on multiple "easy problems of consciousness," involving relations between subjectivity, brain function, and behavior. This review discusses common meanings of "consciousness" regarding psychedelics and considers models of their effects on the brain linked to explanatory claims about consciousness. It calls for epistemic humility about psychedelic research's potential to explain the hard problem while noting ways psychedelics may advance study of specific aspects of consciousness.

Serotonin and psilocybin activate 5-HT1B receptors to suppress cortical signaling through the claustrum

Nature Communications August 19, 2025 Maxwell B. Madden, Chloe Schaefgen, Binita Vedak et al. 4 citations

Serotonin activates 5-HT1B receptors on anterior cingulate cortex inputs to the claustrum, suppressing signaling to parietal association cortex-projecting claustrum neurons. Psilocybin, metabolized to the serotonin receptor agonist psilocin, similarly activates these presynaptic 5-HT1B receptors, reducing cortical signaling through the claustrum. This gain-control mechanism may be directly targeted by psilocybin to modulate downstream cortical network states, offering insight into how the classic psychedelic disrupts widespread brain activity.