SPEAKERS

Recent pharmacological studies on the nature of altered states of consciousness with psychedelic substances such as LSD and psilocybin have emphasized the importance of thalamo-cortical interactions for the emergence of hallucinations. The finding of increased thalamo-cortical coupling suggested reduced thalamic filtering to be a driving mechanism of hallucinations. Here, I will present data from two fMRI studies in which non-pharmacological methods were used to induce altered states of consciousness that comprise hallucinatory experiences. In the first study (N = 19) we used multimodal Ganzfeld stimulation – a technique of perceptual deprivation, where participants are exposed to intense, however, unstructured, homogenous visual and auditory stimulation. In the second study (N = 20) we applied visual flicker stimulation with 3 Hz or 11 Hz, which is frequently used as recreational technique and is well known for its induction of intense, colorful and vivid illusory percepts with strong immersive properties. Before, during and after the interventions we acquired fMRI resting-state data.