Psychedelic states can help researchers understand how the brain reorganizes at a large scale. In nine people scanned before and after taking ayahuasca, topological data analysis of resting-state fMRI connectivity showed a nominal decrease in persistent entropy of H2 features—a measure of higher-dimensional topological structure—that did not survive correction for multiple comparisons and was not reproduced with signed correlations. Exploratory analyses of signal complexity found descriptive but non-significant increases. These preliminary, hypothesis-generating results highlight persistent homology as a potential framework for studying psychedelic-related brain changes, but replication in larger placebo-controlled studies is needed.
Qualia, the first-person subjective qualities of conscious experience, have resisted physical explanation. This paper hypothesizes that qualia are generated in the brain during quantum computational resolution of difficult inverse problems, specifically when non-Clifford magic states are consumed above a threshold rate. Magic states are a quantum resource needed for universal quantum computation. Inverse problems in cognition, like reconstructing 3D shape from a blurry 2D retinal image, are ill-posed and computationally costly. The hypothesis reframes philosophical thought experiments, predicts qualia arise in posterior sensory cortices due to challenging inverse problems in vision and hearing, and explains their absence in simple or many complex systems. The authors discuss recent empirical findings from the Cogitate Consortium.