James M Gold1, Sonia Bansal2, Alan Anticevic3, Youngsun T Cho4, Grega Repovš5, John D Murray3, Britta Hahn2, Benjamin M Robinson2, Steven J Luck6. 1. Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland. Electronic address: jgold@som.umaryland.edu. 2. Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland. 3. Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut. 4. Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut; Child Study Center, Yale University School of Medicine, New Haven, Connecticut. 5. Department of Psychology, University of Ljubljana, Ljubljana, Slovenia. 6. Center for Mind & Brain and Department of Psychology, University of California, Davis, Davis, California.
Abstract
BACKGROUND: Impairments in spatial working memory (sWM) have been well documented in schizophrenia. Here we provide a comprehensive test of a microcircuit model of WM performance in schizophrenia that predicts enhanced effects of increasing delay duration and distractors based on a hypothesized imbalance of excitatory and inhibitory processes. METHODS: Model predictions were tested in 41 people with schizophrenia (PSZ) and 32 healthy control subjects (HCS) performing an sWM task. In one condition, a single target location was followed by delays of 0, 2, 4, or 8 seconds. In a second condition, distractors were presented during the 4-second delay interval at 20°, 30°, 40°, 50°, or 90° from the original target location. RESULTS: PSZ showed less precise sWM representations than HCS, and the rate of memory drift over time was greater in PSZ than in HCS. Relative to HCS, the spatial recall responses of PSZ were more repelled by distractors presented close to the target location and more attracted by distractors presented far from the target location. The degree of attraction to distant distractors was correlated with the rate of memory drift in the absence of distractors. CONCLUSIONS: Consistent with the microcircuit model, PSZ exhibited both a greater rate of drift and greater attraction to distant distractors relative to HCS. These two effects were correlated, consistent with the proposal that they arise from a single underlying mechanism. However, the repulsion effects produced by nearby distractors were not predicted by the model and thus require an updated modeling framework.
BACKGROUND: Impairments in spatial working memory (sWM) have been well documented in schizophrenia. Here we provide a comprehensive test of a microcircuit model of WM performance in schizophrenia that predicts enhanced effects of increasing delay duration and distractors based on a hypothesized imbalance of excitatory and inhibitory processes. METHODS: Model predictions were tested in 41 people with schizophrenia (PSZ) and 32 healthy control subjects (HCS) performing an sWM task. In one condition, a single target location was followed by delays of 0, 2, 4, or 8 seconds. In a second condition, distractors were presented during the 4-second delay interval at 20°, 30°, 40°, 50°, or 90° from the original target location. RESULTS: PSZ showed less precise sWM representations than HCS, and the rate of memory drift over time was greater in PSZ than in HCS. Relative to HCS, the spatial recall responses of PSZ were more repelled by distractors presented close to the target location and more attracted by distractors presented far from the target location. The degree of attraction to distant distractors was correlated with the rate of memory drift in the absence of distractors. CONCLUSIONS: Consistent with the microcircuit model, PSZ exhibited both a greater rate of drift and greater attraction to distant distractors relative to HCS. These two effects were correlated, consistent with the proposal that they arise from a single underlying mechanism. However, the repulsion effects produced by nearby distractors were not predicted by the model and thus require an updated modeling framework.
Authors: Sonia Bansal; Gi-Yeul Bae; Kyle Frankovich; Benjamin M Robinson; Carly J Leonard; James M Gold; Steven J Luck Journal: J Abnorm Psychol Date: 2020-09-03
Authors: John H Krystal; Alan Anticevic; Genevieve J Yang; George Dragoi; Naomi R Driesen; Xiao-Jing Wang; John D Murray Journal: Biol Psychiatry Date: 2017-01-13 Impact factor: 13.382
Authors: Sonia Bansal; Gi-Yeul Bae; Kyle Frankovich; Benjamin M Robinson; Carly J Leonard; James M Gold; Steven J Luck Journal: J Abnorm Psychol Date: 2020-09-03