The claustrum, a thin sheet of neurons deep within the cortex with extremely rich and global input and output connections to myriad other brain regions, has been suspected by neuroscientists of being the seat of consciousness. Because of its location in the brain, the claustrum has been difficult to access or assess. Now a new study from Johns Hopkins, utilizing a new functional MRI (fMRI) technique developed for the purpose, demonstrates a downturn in activity in the claustrum after psilocybin use as compared with taking a placebo. This may be the neural basis of the reduced sense of self or ego, and feeling of connection to the cosmos, in psychedelic experiences. Now the researchers plan to examine claustral activity in various psychiatric disorders such as depression and psychosis as well as assess the effect of other psychedelic substances on its function.
— Via Psych Central