title: Impaired working memory capacity is not caused by failures of selective attention in schizophrenia.
abstract: The cognitive impairments associated with schizophrenia have long been known to involve deficits in working memory (WM) capacity. To date, however, the causes of WM capacity deficits remain unknown. The present study examined selective attention impairments as a putative contributor to observed capacity deficits in this population. To test this hypothesis, we used an experimental paradigm that assesses the role of selective attention in WM encoding and has been shown to involve the prefrontal cortex and the basal ganglia. In experiment 1, participants were required to remember the locations of 3 or 5 target items (red circles). In another condition, 3-target items were accompanied by 2 distractor items (yellow circles), which participants were instructed to ignore. People with schizophrenia (PSZ) exhibited significant impairment in memory for the locations of target items, consistent with reduced WM capacity, but PSZ and healthy control subjects did not differ in their ability to filter the distractors. This pattern was replicated in experiment 2 for distractors that were more salient. Taken together, these results demonstrate that reduced WM capacity in PSZ is not attributable to a failure of filtering irrelevant distractors.
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Catonsville, MD; merickson@mprc.umaryland.edu.
authors.forename: Molly A
authors.initials: MA
authors.lastname: Erickson
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Catonsville, MD;
authors.forename: Britta
authors.initials: B
authors.lastname: Hahn
authors.affiliation: University of California Davis, Center for Mind and Brain, Davis, CA.
authors.forename: Carly J
authors.initials: CJ
authors.lastname: Leonard
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Catonsville, MD;
authors.forename: Benjamin
authors.initials: B
authors.lastname: Robinson
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Catonsville, MD;
authors.forename: Brad
authors.initials: B
authors.lastname: Gray
authors.affiliation: University of California Davis, Center for Mind and Brain, Davis, CA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Luck
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Catonsville, MD;
authors.forename: James
authors.initials: J
authors.lastname: Gold
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*; D013028:Space Perception / Q000502:physiology*
keywords: schizophrenia; selective attention; working memory