Increased working memory-related brain activity in middle-aged women with cognitive complaints

Abstract

Individuals who report subjective cognitive complaints but perform normally on neuropsychological tests might be at increased risk for pathological cognitive aging. The current study examined the effects of the presence of subjective cognitive complaints on functional brain activity during a working memory task in a sample of middle-aged postmenopausal women. Twenty-three postmenopausal women aged 50-60 completed a cognitive complaint battery of questionnaires. Using 20% of items endorsed as the threshold, 12 women were categorized as cognitive complainers (CC) and 11 were noncomplainers (NC). All subjects then took part in a functional magnetic resonance imaging scanning session during which they completed a visual-verbal N-back test of working memory. Results showed no difference in working memory performance between CC and NC groups. However, the CC group showed greater activation relative to the NC group in a broad network involved in working memory including the middle frontal gyrus (Brodmann area [BA] 9 and 10), the precuneus (BA 7), and the cingulate gyrus (BA 24 and 32). The CC group recruited additional regions of the working memory network compared with the NC group as the working memory load and difficulty of the task increased. This study showed brain activation differences during working memory performance in a middle-aged group of postmenopausal women with subjective cognitive complaints but without objective cognitive deficit. These findings suggest that subjective cognitive complaints in postmenopausal women might be associated with increased cortical activity during effort-demanding cognitive tasks.

Figure 1

Activation map for cognitive complainers (CC) – non-complainers (NC) as working memory load was parametrically increased from 0-back to 3-back (p < .005). Orange colors represent activation that is greater for the CC group relative to the NC group as the working memory load increased.