A-193: Premorbid IQ Predicts Verbal Memory Performance Independent of Executive Function

Abstract

Objective: Cognitive reserve is a concept that suggests cognitive abilities are built up over the life course and may compensate for brain damage and cognitive changes. Research has found that educational attainment is associated with cognitive reserve in domains such as executive function and memory performance. However, limited research has explored executive function as a mediator between cognitive reserve and verbal memory performance. Method/Data Selection: Examinees were one hundred-forty-seven adults (mean age=64.1[SD=9.0]) who underwent clinical neuropsychological evaluation for memory concerns. Examinees completed the Test of Premorbid Functioning (TOPF), California Verbal Learning Test-3rd Ed.-Brief (CVLT), Trail Making Test-Part B (TMT-B), and Wisconsin Card Sorting Test (WCST; n=55). Two mediation analyses were run with TMT-B and WCST Perseverative Errors T-scores as respective mediators between TOPF estimated IQ and CVLT Long Delay. Results/Data Synthesis: Significant direct effects were observed between TOPF and CVLT (ps<.05) for both models. No significant indirect effects were seen for the TMT-B model (B=.002;p=.81) and TOPF was not associated with TMT-B (B=.018;p=.09). All paths in the WCST model were significant (ps<.05), but significant indirect effects were not seen (B=.037;p=.09). Conclusions: Current results were mixed. TMT-B was not a significant mediator of cognitive reserve (TOPF) and verbal memory (CVLT Long Delay). WCST was not a significant mediator, but demonstrated significant associations with cognitive reserve and verbal memory. Limitations include selection effects, as patients with severe cognitive impairment may have been unable to TMT-B or WCST, and limited power, as only 55 examinees completed the WCST.