Thought blocking (German: Sperrung), or simply blocking, is a phenomenon that occurs in people with psychiatric illnesses (usually schizophrenia). A person's speech is suddenly interrupted by silences that may last a few seconds to a minute or longer. When the person begins speaking again, after the block, they will often speak about a subject unrelated to what was being discussed when blocking occurred. Blocking is described as an experience of unanticipated, quick and total emptying of When doc...