Differential impact of executive dysfunction on verbal list learning and story recall

The California Verbal Learning Test (CVLT) and the Logical Memory (LM) subtest from the Wechsler Memory Scale-Revised (WMS-R) are generally thought to be interchangeable measures of verbal memory. However, little is known about the effects of executive dysfunction on these tasks. The present study involved 96 patients referred for neuropsychological evaluation who were classified as having either significant executive dysfunction (SED) or minimal executive dysfunction (MED) based on the number of impaired executive tasks. Results showed that the SED group performed significantly worse on CVLT total words learned and most of the recall conditions compared to the MED patients (p <.01). However, performance on both immediate and delayed LM did not significantly differentiate the groups. CVLT measures of semantic clustering, perseveration, intrusions, and false positive errors did not appear to account for the group differences. The current study strongly suggests that the CVLT and the LM subtest are differentially associated with executive dysfunction, and argues for the inclusion of both types of tasks in a comprehensive neuropsychological evaluation.