Loss of financial capacity in Alzheimer's disease: The role of working memory

Recent research has demonstrated that loss of financial capacity is a common consequence of Alzheimer's disease (AD). While progressive cognitive decline is a defining feature of AD, the relationship between such decline and loss of financial capacity in AD remains unclear. Working memory may be strongly associated with financial abilities, as many financial tasks require temporary storage and manipulation of numerical and other data. The present study examined the relationship between financial capacity and working memory in AD patients. Participants included 20 AD patients and 23 cognitively intact older controls. Working memory was conceptualized using Baddeley and colleagues' model, which posits that the three components of the working memory system are the visuospatial sketchpad, phonological loop, and central executive system. The present study examined only the latter two components of working memory. Each participant was administered the Financial Capacity Instrument (FCI), an instrument that directly assesses eight domains of financial activity, and the WAIS-III Working Memory subtests (Digit Span, Arithmetic, Letter-Number Sequencing). AD patients as a group performed significantly below controls on the FCI Total Score and on each of the eight FCI domains and working memory subtests. Within the AD group, measures of the central executive component of working memory (WAIS-III Digits Backward, Arithmetic, and Letter-Number Sequencing tests) showed strong correlations with the FCI domains of basic monetary skills, checkbook management, bank statement management, and bill payment and FCI total score, while a measure of the phonological loop component of working memory (WAIS-III Digits Forward) was not significantly correlated with any FCI domains or with the FCI total score. The results suggest that the multiple domains of financial capacity are primarily correlated with the central executive component of working memory.