General Mathematical Ability Predicts PASAT Performance in MS Patients: Implications for Clinical Interpretation and Cognitive Reserve

Objectives: The Paced Auditory Serial Addition Test (PASAT) is used to assess cognitive status in multiple sclerosis (MS). Although the mathematical demands of the PASAT seem minor (single-digit arithmetic), cognitive psychology research links greater mathematical ability (e.g., algebra, calculus) to more rapid retrieval of single-digit math facts (e.g., 5+6=11). The present study evaluated the hypotheses that (a) mathematical ability is related to PASAT performance and (b) both the relationship between intelligence and PASAT performance as well as the relationship between education and PASAT performance are both mediated by mathematical ability. Methods: Forty-five MS patients were assessed using the Wechsler Test of Adult Reading, PASAT and Calculation Subtest of the Woodcock-Johnson-III. Regression based path analysis and bootstrapping were used to compute 95% confidence intervals and test for mediation. Results: Mathematical ability (a) was related to PASAT (β=.61; p\u3c.001) and (b) fully mediated the relationship between Intelligence and PASAT (β=.76; 95% confidence interval (CI95)=.28, 1.45; direct effect of Intelligence, β=.42; CI95=−.39, 1.23) as well as the relationship between Education and PASAT (β=2.43, CI95=.81, 5.16, direct effect of Education, β=.83, CI95=−1.95, 3.61). Discussion: Mathematical ability represents a source of error in the clinical interpretation of cognitive decline using the PASAT. Domain-specific cognitive reserve is discussed. (JINS, 2016, 22, 375–378)

Working Memory Mediates the Relationship Between Intellectual Enrichment and Long-Term Memory in Multiple Sclerosisan Exploratory Analysis of Cognitive Reserve

Some individuals with multiple sclerosis (MS) show decrements in long-term memory (LTM) while other individuals do not. The theory of cognitive reserve suggests that individuals with greater pre-morbid intellectual enrichment are protected from disease-related cognitive decline. How intellectual enrichment affords this benefit remains poorly understood. The present study tested an exploratory meditational hypothesis whereby working memory (WM) capacity may mediate the relationship between intellectual enrichment and verbal LTM decline in MS. Intellectual enrichment, verbal LTM, and WM capacity were estimated with the Wechsler Test of Adult Reading and Peabody Picture Vocabulary Test, delayed recall of the Hopkins Verbal Learning Test-Revised and Logical Memory of the Wechsler Memory Scale, and Digit Span Total, respectively. Intellectual enrichment predicted LTM (B=.54; p=.003) and predicted WM capacity (B=.91; p\u3c.001). WM capacity predicted LTM, (B=.44; p\u3c.001) and fully mediated the relationship between intellectual enrichment (B=.24; p=.27) and LTM (B=.33, p=.03), Sobel test, Z=3.31, p\u3c.001. These findings implicate WM capacity as an underlying mechanism of cognitive reserve and are an initial first step in understanding the relationship between intellectual enrichment, WM, and LTM in MS. (JINS, 2014, 20, 1-5

General Mathematical Ability Predicts PASAT Performance in MS Patients: Implications for Clinical Interpretation and Cognitive Reserve

Objectives: The Paced Auditory Serial Addition Test (PASAT) is used to assess cognitive status in multiple sclerosis (MS). Although the mathematical demands of the PASAT seem minor (single-digit arithmetic), cognitive psychology research links greater mathematical ability (e.g., algebra, calculus) to more rapid retrieval of single-digit math facts (e.g., 5+6=11). The present study evaluated the hypotheses that (a) mathematical ability is related to PASAT performance and (b) both the relationship between intelligence and PASAT performance as well as the relationship between education and PASAT performance are both mediated by mathematical ability. Methods: Forty-five MS patients were assessed using the Wechsler Test of Adult Reading, PASAT and Calculation Subtest of the Woodcock-Johnson-III. Regression based path analysis and bootstrapping were used to compute 95% confidence intervals and test for mediation. Results: Mathematical ability (a) was related to PASAT (β=.61; p\u3c.001) and (b) fully mediated the relationship between Intelligence and PASAT (β=.76; 95% confidence interval (CI95)=.28, 1.45; direct effect of Intelligence, β=.42; CI95=-.39, 1.23) as well as the relationship between Education and PASAT (β=2.43, CI95=.81, 5.16, direct effect of Education, β=.83, CI95=-1.95, 3.61). Discussion: Mathematical ability represents a source of error in the clinical interpretation of cognitive decline using the PASAT. Domain-specific cognitive reserve is discussed