14 The Moderating Effects of Working Memory on Sex and Nonverbal Learning and Memory Among Elderly Adults

Abstract

Objective:Previous research evidences men, on average, perform better than women on nonverbal tasks. Conversely, literature evidences women, on average, perform better on memory tasks. Proposed explanations for this discrepancy include, increased parietal lobe volume to hormonal differences. Some research also suggests men have greater working memory (WM) abilities than women on tasks involving holding visual information. As such, it is possible more robust WM performance in men may translate to better performance on nonverbal tasks with an immediate and delayed visual memory component. The current study examined if WM performance moderates the relationship between sex and nonverbal learning and memory in a community clinic population of older adults referred for cognitive concerns.Participants and Methods:Data was drawn from archival medical records of patients who underwent neuropsychological assessment in an outpatient, community clinic after being referred for cognitive concerns in the context of a variety of neurodegenerative and neurological conditions. Records of patients between the ages of 65 and 91 who completed the Brief Visuospatial Memory Test (BVMT-R) and WAIS-IV Digit Span (DS) were selected from the broader clinic sample of patients seen between 2019 and 2022. The total sample consisted of 302 older adults with a mean age of 75.11 (SD=6.06) and an average of 15.54 years of education (SD=2.51); 145 (48%) were women. Hierarchical regression analyses were used to examine the effects of sex, WM, and the interaction between sex and WM on BVMT learning and memory scores, while controlling for age and education. An independent samples t-test was also computed to examine sex differences on DS working memory scores.Results:The optimal linear combination of sex, WM, and the interaction between sex and WM accounted for 24.7% of the variance in BVMT total learning scores (F(5, 296)=20.79, p>0.05). There were no significant main effects of sex or the interaction between sex and WM on nonverbal learning or nonverbal memory (p>0.05). However, a strong trend was observed for the effect of sex on nonverbal memory (B=-0.69, t(5)=-1.91, p=0.057). A main effect of WM on nonverbal learning (B=0.42, 95% CI [0.25, 0.59], p<0.05) and memory (B=0.21, 95% CI [0.12, 0.29], p<0.05) was observed. Sex differences on WM measures were not observed (p>0.05).Conclusions:Significant main effects of sex on nonverbal learning and memory were not found, though strong trends were observed between sex and nonverbal memory performance. While the relationships between WM and nonverbal learning and memory were trending toward significance, the predicted sex differences on WM performance were not found. The trend toward significance observed between sex and nonverbal memory may be the “carryover” effect from ancillary spatial skills that prior research has shown to be more robust amongst men, including mental rotation and visual construction. Findings from the current study align with the BVMT-R technical manual, which reported no significant contribution from sex in any learning or recall scores within their normative sample.