The relation of executive functioning to CVLT-II learning, memory, and process indexes

Previous research has found that executive functioning plays a role in memory performance. This study sought to determine the amount of variance accounted for in the California Verbal Learning Test-Second Edition (CVLT-II) by a global executive-functioning factor score. Archival data were extracted from 285 outpatients in a mixed neurologic sample. Measures used included: CVLT-II, Wisconsin Card-Sorting Test (Perseverative Errors), Trail-Making Test-Part B, Controlled Oral Word Association Test, Animal Naming, and Wechsler Adult Intelligence Scale-Third Edition Similarities. Executive data were reduced to a single executive-functioning factor score for each individual. Regression was used to determine the amount of variance accounted for by executive functioning in CVLT-II performance. Executive functioning accounted for minimal variance (0%-10%) in the following CVLT-II indexes: Total Learning (Trials 1-5), Semantic Clustering, Repetitions, Intrusions, and False Positives. However, executive functioning accounted for substantial variance (24%-31%) in CVLT-II performance for both Short- and Long-Delay Recall indexes and most discriminability indexes. CVLT-II indexes that would intuitively be associated with executive functioning accounted for a smaller-than-expected amount of variance. Additionally, level of executive functioning was related to level of CVLT-II performance. These results suggest that clinicians should consider executive deficits when interpreting mild-to-moderate memory impairments in recall and discriminability functions but that executive abilities have little effect on other aspects of memory.