Abstract

In this chapter we have explored the model of impaired self-monitoring which has been proposed to underlie the pathophysiology of auditory hallucinations and delusions in schizophrenia. We begin with an overview of the model from its beginnings in sensorimotor literature to its elaboration by Chris Frith. We then review the neuropsychological support and functional neuroimaging data of verbal self-monitoring in healthy individuals, inner speech and auditory hallucinations. A summary of our most recent data of overt verbal self-monitoring as measured by functional magnetic resonance imaging in healthy individuals as well as in patients with schizophrenia, both acutely psychotic and in remission, follows. We complete the chapter with a proposal for the neural circuitry involved in self-monitoring based on our behavioural and neuroimaging data and proposals for future research.

Introduction

That we recognize our thoughts, even the most bizarre and unpleasant ones, as arising from our own minds is a phenomenon which we take for granted. Associated with this is our ability to distinguish ourselves from others at a basic physical level and in terms of more nebulous concepts like ideas, beliefs and values. Yet most of us can also recall moments, such as upon wakening, when we've wondered if an experience was real or a dream. The experience of psychosis may represent an extreme example of this uncertainty. A hallucination, one of the cardinal features of psychosis, is a perception which occurs in the absence of a corresponding sensory stimulus.