The multimodal Ganzfeld-induced altered state of consciousness induces decreased thalamo-cortical coupling.
Scientific Reports October 29, 2020 Timo Torsten Schmidt, Nisha Jagannathan, Michal Ljubljanac et al.
An altered state of consciousness (ASC) induced by non-pharmacological Ganzfeld stimulation—where participants are exposed to intense, homogeneous visual and auditory input—progressively decouples the thalamus from the cortex, as measured by fMRI. This decoupling contrasts with psychedelic-induced ASCs, which typically show increased thalamo-cortical coupling. The Ganzfeld ASC also increased eigenvector centrality in core regions of the default mode network (DMN), opposite to the reduced DMN activity seen with psychedelics. These findings suggest an imbalance between sensory bottom-up and internally generated top-down signaling.