Thought disorder in schizophrenia: impairment in contextual processing via integrative failures in cognition

Formal thought disorder is a critical dysfunction in schizophrenia whose cause remains uncertain, but whose explanation may greatly further our understanding of the disease. Thought disorder in patients with schizophrenia has been hypothesized to involve a disturbance in the internal representation of context. Positive symptoms of schizophrenia attributable to thought disorder display a lack of organization that may be accounted for by an absence of normal contextual processing occurring within the operations of the executive system. But the precise nature and pervasiveness of the deficient cognitive operation remain undistinguished. It is proposed here that the assimilatory functions of the brain appear to lack the ability to perform a particular type of integrative operation when presented with heterogeneous information. This deficit involves committing cognitive misattributions through a confusion of mental terms via a process in thought analogous to a linguistic failure to correctly interpret deictic referents. Both proposed deficits in mental deixis and analogous "metarepresentational" deficits in schizophrenia potentially involve a failure to draw information for a conclusion from a separate framework of relations in integrative fashion. These deficits appear to involve a failure to take an interpreted piece of information as an output from a particular mental task and incorporate it into a new operational scheme, and a central attribute to the deficit is that there is a loss of an effective or adequate integration of separate strata of information. Potential neurobiological correlates to such a system based on current knowledge about schizophrenia neurocircuitry, as well as implications for testing, are also discussed.