An international team pooled data from 11 functional MRI studies—over 500 brain scans of 267 volunteers dosed with LSD, psilocybin, mescaline, DMT or ayahuasca—to pin down how classic psychedelics reshape neural wiring. Instead of tearing down major networks like the default mode system, they found these drugs boost cross-talk between sensory regions (vision, touch, hearing) and higher-order hubs for abstract thought and self-reflection. In plain terms, psychedelics break down the usual barrier between perceiving the outside world and internal mental chatter. Lead author Manesh Girn of UCSF says that by running all scans through a single analytical framework, the consortium uncovered reliable “benchmarks” for psychedelic effects on brain connectivity. They saw consistent increases in information flow through core circuits that coordinate perception and action. Other claimed effects—like wholesale network disintegration—didn’t hold up once everyone agreed on processing methods. Observers such as Amy Kuceyeski of Weill Cornell praise the rigor but note gaps, like how age or sex might shape these neural shifts. Joshua Siegel from NYU Langone points out that these agreed-upon biomarkers will steer efforts to design new compounds that retain therapeutic value without hallucinogenic side-effects. Danilo Bzdok at McGill, who helped broker the project’s cross-continent collaboration, emphasizes how rare such consensus is in the fragmented field of psychedelic research. Having a shared set of brain-connectivity markers could speed up trials of the 150 new “psychedelic-like” drugs now in development.