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Hochberger WC, Thomas ML, Joshi YB, Swerdlow NR, Braff DL, Gur RE, Gur RC, Light GA. Deviation from expected cognitive ability is a core cognitive feature of schizophrenia related to neurophysiologic, clinical and psychosocial functioning. Schizophr Res 2020; 215:300-307. [PMID: 31744751 DOI: 10.1016/j.schres.2019.10.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/03/2019] [Accepted: 10/06/2019] [Indexed: 11/26/2022]
Abstract
Cognitive functioning in schizophrenia is characterized by a generalized impairment in current cognitive ability based on traditional population-based norms. However, these norms assume a normal cognitive trajectory and do not directly account for illness-related declines from expected cognitive potential. Indeed, schizophrenia patients exhibit even greater deviation between their observed and expected cognitive functioning based on expanded norms that leverage premorbid variables resistant to illness-related features. The current study further quantified the extent to which illness-related features account for this deviation from expectation and assessed its relationship to neurophysiologic (mismatch negativity, P3a, theta oscillations), clinical, and psychosocial functioning in schizophrenia patients. Expected cognitive ability (PENN-CNB global cognition) in patients (n = 684) was calculated using healthy comparison subject (n = 660) weighted regression based on premorbid variables resistant to illness-related decline (demographics, single-word reading, parental education). The magnitude of any deviation between current (observed) and regression-predicted (expected) cognitive ability was calculated. Results indicated that 24% (n = 164) of the total patient population exhibited significant (≥-1.96 SD) deviation between observed and expected global cognitive ability. Interestingly, 20% of the total patient population (n = 136) had "normal" range cognitive performance when using traditional population-based norms, but also had significant deviation from expected cognitive ability. The magnitude of this deviation was associated with more severe neurophysiologic abnormalities, longer illness duration, higher levels of negative symptoms, and worse psychosocial functioning. Assessment of cognitive deviation is thus a complementary metric for characterizing the severity of illness-related cognitive declines in patients, while also reflecting the expression and severity of key endophenotypes of schizophrenia.
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Affiliation(s)
- W C Hochberger
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - M L Thomas
- Department of Psychology, Colorado State University, Fort Collins, CO, USA
| | - Y B Joshi
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - N R Swerdlow
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - D L Braff
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - R E Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | - R C Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | - G A Light
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California San Diego, La Jolla, CA, USA.
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Hochberger WC, Joshi YB, Zhang W, Thomas ML, Braff DL, Swerdlow NR, Light GA. Decomposing the constituent oscillatory dynamics underlying mismatch negativity generation in schizophrenia: Distinct relationships to clinical and cognitive functioning. Int J Psychophysiol 2019; 145:23-29. [PMID: 30586570 PMCID: PMC7261144 DOI: 10.1016/j.ijpsycho.2018.12.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 12/04/2018] [Accepted: 12/21/2018] [Indexed: 12/31/2022]
Abstract
Abnormalities in early auditory information processing (EAIP) contribute to higher-order deficits in cognition and psychosocial functioning in schizophrenia. A passive auditory oddball paradigm is commonly used to evoke event-related potential (ERP) measures of EAIP reflecting auditory sensory registration and deviance detection, including mismatch negativity (MMN) and P3a responses. MMN and P3a have been extensively studied in healthy subjects and neuropsychiatric patient populations and are increasingly used as translational biomarkers in the development of novel therapeutics. Despite widespread use, relatively few studies have examined the constituent oscillatory elements and the extent to which sensory registration and deviance detection represent distinct or intercorrelated processes. This study aimed to determine the factor structure and clinical correlates of these oscillatory measures in schizophrenia patients (n = 706) and healthy comparison subjects (n = 615) who underwent clinical, cognitive, and functional characterization and EEG testing via their participation in the Consortium of Genomics in Schizophrenia (COGS-2) study. Results revealed significant deficits in theta-band (4-7 Hz) evoked power and phase locking in patients. Exploratory factor analyses of both ERP and oscillatory measures revealed two dissociable factors reflecting sensory registration and deviance detection. While each factor shared a significant correlation with social cognition, the deviance detection factor had a unique relationship to multiple cognitive and clinical domains. Results support the continued advancement of functionally relevant oscillatory measures underlying EAIP in the development of precognitive therapeutics.
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Affiliation(s)
- W C Hochberger
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States of America; Department of Psychiatry, University of California San Diego, La Jolla, CA, United States of America
| | - Y B Joshi
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States of America
| | - W Zhang
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States of America
| | - M L Thomas
- Colorado State University, Department of Psychology, Fort Collins, CO, United States of America
| | - D L Braff
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States of America
| | - N R Swerdlow
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States of America
| | - G A Light
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States of America; Department of Psychiatry, University of California San Diego, La Jolla, CA, United States of America.
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