Selective Deficits in Prefrontal Cortex Function in Medication-Naive Patients With Schizophrenia

Abstract

DISTURBANCES in prefrontal cortex (PFC) functioning have long been implicated in schizophrenia and have been linked to working memory (WM) deficits.¹ Working memory is typically defined as the ability to temporarily maintain and manipulate information on-line.² Several lines of research support a link between PFC and WM dysfunction in schizophrenia^3-19 (for contrasting evidence, see the articles by Manoach et al¹⁷ and Fletcher et al²⁰). However, many studies have examined large areas of PFC, combining subregions that may be functionally distinct.^9,13,15,16 Thus, it is not clear whether all or only certain subregions of PFC show disturbed patterns of cognition-related activation in schizophrenia. Additionally, most functional imaging studies have chosen tasks based on their sensitivity to frontal lobe dysfunction (eg, Wisconsin Card Sorting Test)^16,19 or used tasks that tap multiple components of WM,^9,14,15 making it difficult to determine which specific processes are disturbed in schizophrenia.