Left striato-pallidal hyperactivity in schizophrenia. Part II: Phenomenology and thought disorder.

Our previous paper summarized abundant evidence that schizophrenic patients show forms of sensory and motor hemineglect compatible with a left striato-pallidal hyperactivity model of schizophrenia. In this paper we discuss how the model may also account for some of the cognitive and phenomenological aspects of this disorder. Hemineglect can be associated with pallidal hyperactivity through its mediation of the anterior attention system of the frontal lobe. We postulate that this same attentional deficit can also affect higher functions such as the control of language and thought by internal motivations. Many symptoms of schizophrenia can be explained as a form of hemineglect of these higher functions.