Assessing functional connectivity among a putative response inhibition network in people with schizophrenia
Item
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Title
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Assessing functional connectivity among a putative response inhibition network in people with schizophrenia
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Identifier
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d_2009_2013:3fedd11b9c50:11199
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identifier
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11525
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Creator
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Nair-Collins, Sangeeta,
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Contributor
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Matthew J. Hoptman
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Date
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2012
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Language
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English
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Publisher
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City University of New York.
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Subject
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Clinical psychology | Cognitive psychology
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Abstract
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Schizophrenia (SZ) is a psychotic disorder that results in, among other deficits, cognitive impairments that may affect a person's inability to integrate meaningfully into society, maintain interpersonal skills, and remain employed. Pervasiveness of cognitive impairments is recognized as a primary predictor of poor global outcome and chronic and is linked to long-term functioning. One of these impairments is response inhibition, the ability to withhold a prepotent response. Researchers have attempted to study this deficit by assessing response inhibition during performance of the stop signal task.;The dysconnection hypothesis of schizophrenia suggests that the symptoms of schizophrenia may result from impaired functional connectivity among neural structures. To examine this hypothesis, we used functional magnetic resonance imaging (fMRI) to assess functional connectvity among distinct neural structures involved in response inhibition. Subjects also were tested with a stop signal task. Our studies revealed the following: First, we observed large effect size deficits (ranging from 0.44 to 0.55) in functional connectivity at rest among structures involved in response inhibition and this deficit was increased among the inpatient population. Second, we found evidence of continued functional dysconnectivity among regions during task performance among the inpatient population, a finding absent among the outpatient population. Additionally, behavioral results mimicked this pattern of deficit among the inpatient population. Third, as expected we observed a temporal stability of the resting state functional connectivity among controls. Interestingly, although outpatients initially exhibited decreased connectivity patterns at rest, these patterns normalized during the course of task performance as well as during the rest period following task performance. This pattern was not observed in the inpatient population.;Taken together, these findings suggest that people with schizophrenia exhibit impaired connectivity among structures in the response inhibition network at rest and during task and these deficits may be related to an impaired ability to control motor action, thus leading to undesirable behavior. In addition, the observed post-task normalization of the network among outpatients may suggest that they are able to better recruit these regions during task performance and may be reflective of improved symptomatology.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Psychology
