The association of symptoms of schizophrenia and dysfunction of specific brain regions
Most previous attempts to determine the neurophysiological mechanisms associated with schizophrenia have examined schizophrenia as an unitary, or at most a binary (e.g., positive versus negative), entity. This study made use of a system-level approach in which individual symptoms were examined for their relationship to the dysfunction of specific brain regions. Twenty-seven patients with schizophrenia were assessed for severity of alogia, affective flatness, hallucinations, and delusions. Dysfunction of specific brain regions was assessed using neuropsychological tests sensitive to damage of selective brain regions. Of these, the reliable ones used in the analyses were word fluency for left-frontal functioning, design fluency for right-frontal functioning, and digit-sequences recall for left-temporohippocampal functioning. As expected, alogia was associated with left-frontal dysfunction. Unexpectedly, alogia was also associated with right-frontal dysfunction. In addition, as expected, affective flatness was associated with right-frontal dysfunction, but this association was not significantly greater than that of affective flatness with left-temporohippocampal dysfunction. By contrast, hallucinations and delusions were not associated with dysfunction of any of these brain regions. A neuropsychological model is presented to account for two patterns of affective flatness and alogia: their co-occurrence, associated with general frontal dysfunction, and affective flatness occurring without alogia, associated with right-, but not left-, frontal dysfunction.
Biology, Neuroscience, Psychology, Psychobiology, Psychology, Clinical, Psychology, Physiological
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign