Cognitive psychiatry of mediumship: A genetic, neuroconnectomic, interhemispheric, and psychofunctional hypothesis of brain organization in mediums

Abstract

Mediumship is a complex human phenomenon that can be investigated by cognitive psychiatry and consciousness neuroscience without theological assumptions or psychopathological reductionism. This study aimed to formulate and theoretically substantiate a neuroconnectomic, genetic, and psychofunctional hypothesis of mediumship as a network phenotype characterized by greater interhemispheric integration and lower functional segregation of cognitive-affective processes, and to establish formal guidelines for a comparative multimodal experimental protocol to test it empirically. This theoretical-heuristic essay presents a narrative synthesis of genomic, neurophysiological, psychometric, and preclinical evidence and delineates a prospective case–control protocol. The historical hypothesis of greater interhemispheric integration was compared with a 2025 exome study that identified recurrent rare variants in candidate genes, including EPHB6 and GPRIN2, without demonstrating causality or a genotype–connectome association. Studies published from 2023 to 2026 indicate state-dependent changes in spectral power and network topology during mediumistic trance and hypnosis, heterogeneous neural correlates across trance practices, metric-dependent sex differences in connectivity, and no replicable stable association between trait absorption and brain connectivity. Preclinical evidence supports a role for EphB6/EphrinB2 in cortical neuronal spacing but cannot be extrapolated to human connectivity or mediumship. The model is biologically plausible and empirically testable, but remains hypothetical. Independent replication requires prespecified phenotyping, equivalent active controls, confirmatory genotyping, DTI, resting-state fMRI, high-density EEG, psychometrics, and rigorous control of ancestry, brain size, motion, task, and multiple comparisons.