Thought as action: Inner speech, self-monitoring, and auditory verbal hallucinations

Passivity experiences in schizophrenia are thought to be due to a failure in a neurocognitive action self-monitoring system (NASS). Drawing on the assumption that inner speech is a form of action, a recent model of auditory verbal hallucinations (AVHs) has proposed that AVHs can be explained by a failure in the NASS. In this article, we offer an alternative application of the NASS to AVHs, with separate mechanisms creating the emotion of self-as-agent and other-as-agent. We defend the assumption that inner speech can be considered as a form of action, and show how a number of previous criticisms of applying the NASS to AVHs can be refuted. This is achieved in part through taking a Vygotskian developmental perspective on inner speech. It is suggested that more research into the nature and development of inner speech is needed to further our understanding of AVHs. (c) 2005 Elsevier Inc. All rights reserved.