B - 100 Psychomotor Vs. Cognitive Processing Speed in Episodic Verbal Memory

Abstract Objective Processing speed has been shown to positively correlate with episodic memory. However, few studies have explored the nuanced relationship between processing speed and memory. This study explores the types of processing speed measures (e.g., psychomotor vs. cognitive) in relation to episodic verbal memory. Method Participants (N = 231; Mage = 56.73; female = 62.3%) completed the Weschler Test of Adult Reading (WTAR), Grooved Pegboard Test (GPB), Weschler Adult Intelligence Scale-Fourth Edition Coding (WAIS-CD), Trail Making Test-A (TMT-A), Delis-Kaplan Executive Function System-Word Reading (DKEFS-1), and the DKEFS-Color Naming (DKEFS-2) as part of a neuropsychological assessment. Sum of normed z-scores from the California Verbal Learning Test-Second Edition Immediate Recall, List-B, Short-Delayed Free Recall, and Long-Delayed Free Recall created a composite score representing memory. Results Hierarchical linear regression showed premorbid (p < 0.001) and motor functioning (p < 0.001) in a significant Model 1 (p < 0.001), explaining 19.8% of the variance (AdjustedR2 = 0.198). Model 2 was significant (F (6, 178) = 12.95, p < 0.001) and explained an additional 8.2% (AdjustedR2 = 0.280). Only WAIS-CD (β = 0.20, p = 0.014) and TMT-A (β = 0.19, p = 0.012) emerged as significant independent predictors. Conclusion Results showed that both variables involving psychomotor processing speed were independent predictors of episodic verbal memory even after controlling for premorbid and motor functioning. Results provide further clarity into the relationship between processing speed and episodic memory. Future research should attempt to more stringently control for other physical factors that may account for variance in this relationship to ensure replicability.