Mechanisms of internalization in schizophrenia: The roles of salience dysregulation and cognitive dysmetria

The positive symptoms of schizophrenia (hallucinations and delusions) are unique to the schizophrenic disorders, and are a particularly debilitating symptom of psychopathology (APA, 2000). Salience dysregulation theory attempts to explain the presence of hallucinations and delusions through the notion of augmented incentive salience, wherein irregular dopamine neurotransmission results in otherwise neutral or innocuous stimuli becoming salient (Berridge & Robinson, 1998; Kapur, 2003, 2004). The result is the perception of images and associations that do not exist (Kapur, 2003, 2004). Alternatively, cognitive dysmetria theory conceptualizes schizophrenia in terms of cerebellar-cerebrum disconnectivity resulting in mis-processing of incoming information. The disconnectivity results in an inability to distinguish between internal and external sources of information, causing hallucinations and delusions (Andreasen, Nopoulos, O’Leary, Miller, Wassink, & Flaum, 1999; Andreasen & Pierson, 2008). Problematically, neither salience dysregulation theory nor cognitive dysmetria theory is capable of accounting for the dependent relationship between salience attribution and information processing. A framework built on the basis of the wake-sleep algorithm for unsupervised learning in neural networks (Hinton, Dayan, Frey, & Neal, 1995) is proposed to facilitate the synthesis of salience dysregulation theory and cognitive dysmetria theory to provide a causal explanation of the neurocognitive mechanisms underlying the positive symptoms of schizophrenia. Abstract Mechanisms of internalization in schizophrenia: The roles of salience dysregulation and cognitive dysmetria