Development and Validation of Norm-Referenced Measures of Reaction Time Inconsistency
| dc.contributor.author | Brewster, Paul W. H. | |
| dc.contributor.supervisor | MacDonald, Stuart Warren Swain | |
| dc.contributor.supervisor | Tuokko, Holly A. | |
| dc.date.accessioned | 2015-04-28T20:25:07Z | |
| dc.date.available | 2015-04-28T20:25:07Z | |
| dc.date.copyright | 2015 | en_US |
| dc.date.issued | 2015-04-28 | |
| dc.degree.department | Department of Psychology | |
| dc.degree.level | Doctor of Philosophy Ph.D. | en_US |
| dc.description.abstract | Objective: The purpose of this dissertation was to determine whether measures of reaction time inconsistency (RTI) can be applied clinically to detect cognitive impairment in older adults. Methods: Data were obtained from the Victoria Longitudinal Study (VLS), a longitudinal study of healthy aging, and PREVENT, a multivariate study of risk factors for Alzheimer’s disease. Study 1 examined effects of task complexity and computational approach on the association between RTI and physical and cognitive functioning in participants of the VLS. Study 2 assembled normative data from the VLS and standardized RTI data from an independent VLS cohort against these normative data. Significant Study 1 findings were replicated in Study 2 using the obtained RTI T-Scores, and the clinical utility of results were evaluated using stratum specific likelihood ratios (SSLRs). Study 3 replicated Study 2 analyses in data from PREVENT. Results: Results of Study 1 identified four operationalizations of RTI from a choice reaction task that yielded consistent significant associations with cross-sectional cognitive performance. Consistent associations were not observed between these scores and cognitive change or performance on measures of physical functioning. Study 2 replicated Study 1 findings in an independent sample using RTI T-Scores. SSLRs supported the clinical utility of measures of RTI for detecting prevalent cognitive impairment. Study 3 replicated findings from Study 2, but SSLRs indicated that only low RTI scores yielded associations of sufficient reliability for clinical interpretation. Consistent with Study 1 and Study 2, associations between RTI T-Scores and measures of physical function were nonsignificant. Conclusions: Low RTI T-Scores were shown across two samples to be associated with a clinically meaningful reduction in the odds of cognitive impairment. Further research is needed in order to clarify the utility of high RTI scores for positive prediction of cognitive impairment. | en_US |
| dc.description.scholarlevel | Graduate | en_US |
| dc.identifier.uri | http://hdl.handle.net/1828/6041 | |
| dc.language | English | eng |
| dc.language.iso | en | en_US |
| dc.rights | Available to the World Wide Web | en_US |
| dc.rights.uri | http://creativecommons.org/publicdomain/zero/1.0/ | * |
| dc.subject | Aging | en_US |
| dc.subject | Reaction time | en_US |
| dc.subject | Intraindividual variability | en_US |
| dc.subject | Psychometrics | en_US |
| dc.subject | Cognitive impairment | en_US |
| dc.title | Development and Validation of Norm-Referenced Measures of Reaction Time Inconsistency | en_US |
| dc.type | Thesis | en_US |