Cortex in German also called cortex is a term for cortical structures and describes in the physiological sense the outer layer of an organ. In the CNS (central nervous system), there is the cerebral cortex (cortex cerebri) and the cerebellar cortex (cortex cerebrelli). Both are cortical structures, the cortex is usually used here to describe the brain surface, i.e. the gray matter. In hypnosis, the client is put into a hypnotic trance. During the trance, two regions of the brain are shut down: the prefrontal cortex and the precuneus. The former is responsible for planning and linking reason and decisions. Thus, under hypnosis, it is possible to turn off reason or even the inner critic and pave the way to the subconscious mind.