Cognition in schizophrenia (SCZ) has been reported to be heterogeneous. Some have ascribed this to the existence of cognitive subtypes, while others have attributed heterogeneity to the types of assessments used and the implications of various research designs. In absence of a uniform standardized battery, The MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) Consensus Cognitive Battery (MCCB) was developed to measure the effects of pharmacological treatment. Other neuropsychological tasks such as the Attention Network Test (ANT), Change Localization (CL), and Stop Signal Task (SST) have also been heavily researched in this population. The overall aim of this dissertation is to assess not only the participant performance on these tasks, but also the test-rest reliability of these assessments in a relatively short retest interval (14±2 days) in a Healthy Volunteer (HV) and SCZ group. In addition, the relationship between Continuous Performance Test-Identical Pairs (CPT-IP), an attention task (ANT), and working memory task (CL) was explored to examine the potential working memory (WM) component of CPT-IP. Lastly, to better understand the heterogeneity of cognition observed in SCZ, Intraindividual Variability (IIV) in performance of SST was compared in relation to other tasks. The results indicated that the MCCB has fair to excellent test-retest reliability in both groups with minimal practice effect (PE) in SCZ. Most interesting, two distinct cognitive profiles were observed: cognitively-normal and below-normal. The 4-digit condition of CPT-IP was found to be the most difficult in both groups. The primary metrics of CPT-IP lacked an association with the three primary domains of ANT in HV and SCZ. No relationship was observed between WM and CPT-IP in HV, primarily due to CL’s ceiling effect, while in SCZ, moderate to strong associations in these tasks were observed. Lastly, little to no relationship was observed between IIV and MCC domain scores in HV and SCZ. The HV group demonstrated some relationship between IIV and domains of ANT. The SCZ group failed to show similar relationships primarily due to larger inter-individual variability. Taken together, the findings of this dissertation suggest the potential for cognitive heterogeneity unrelated to PE and reliability of tasks. / 2021-10-07T00:00:00Z
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/38585 |
| Date | 07 October 2019 |
| Creators | Shaafi Kabiri, Nina |
| Contributors | Thomas, Kevin C., Palumbo, Carole |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
| Rights | Attribution-NonCommercial-ShareAlike 4.0 International, http://creativecommons.org/licenses/by-nc-sa/4.0/ |
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