VALIDITY OF THE CONSTRUCT OF NONVERBAL MEMORY - A FACTOR-ANALYTIC STUDY IN A NORMAL ELDERLY SAMPLE

One problem in evaluating the construct of nonverbal memory is finding a purely nonverbal memory measure. Encouraged by initial research wit h a new measure, the Visual Spatial Learning Test (VSLT), we examined nonverbal memory in a normal elderly sample. Subjects were 460 communi ty-dwelling individuals between the ages of 55-95. All received neurop sychological batteries which included the Wechsler Adult Intelligence Scale-Revised, the Wechsler Memory Scale-Revised, the Rey Auditory Ver bal Learning Test, and the VSLT. Two variable sets were created to avo id overlapping immediate and delayed recall trials for the same stimul us materials. Exploratory factor analyses using two different extracti on methods were performed. Across analyses a single general memory fac tor was observed, no modality or time specific factors were found. If it can be assumed that we used adequate measures of nonverbal memory, our results combine with prior research to challenge the validity of t he construct of nonverbal memory as distinct from verbal memory, espec ially in older normal adult populations.