Using an Implicit Memory Task to Estimate Premorbid Memory

Abstract

Clinicians are often asked to determine if significant memory loss has occurred. Clinical judgment figures prominently in making these determinations, because there is no accepted, objective method for estimating premorbid memory. Two studies were designed to explore the utility of an implicit memory task, Anagrams Solutions, for estimating premorbid memory ability. A secondary goal was to identify predictors of immediate and delayed memory measured by the Repeatable Battery for the Assessment of Neuropsychological Status using selected intellectual (IQ) and demographic variables. Participants in both studies were administered the implicit memory task, explicit memory measures, and IQ estimate. Results revealed that Anagrams Solutions was not a useful estimate of premorbid memory and that a combination of IQ and demographic variables accounted for 24-31% of the variance in measured memory performances. Findings point to the need for caution in interpreting scores on these variables as valid estimates of premorbid memory functioning.

Predicting Premorbid Memory Functioning in Older Adults

“…The current study sought to predict premorbid memory abilities with demographic variables and premorbid intellect in a sample of cognitively intact older adults, and then apply those prediction formulae to a sample of cognitively impaired older adults. Consistent with the limited research in this area (Gladsjo et al, 1999; Hilsabeck & Sutker, 2009; Isella et al, 2005; Schretlen et al, 2005; Williams, 1997), current scores on verbal and visual learning and memory measures in cognitively intact elders were predicted by demographic variables and an estimate of premorbid intellect. Interestingly, the estimate of premorbid intelligence (WRAT-3 Reading) significantly contributed to three of the models, as there has been considerable debate within neuropsychology as to how much intelligence and other cognitive abilities should correlate (Dodrill, 1997; Tremont, Hoffman, Scott, & Adams, 1998).…”

“…Second, the current study only examined two measures of learning and memory, and specific formulae are needed for other memory tests. Third, as noted earlier, the variance accounted for in the current formulae was low, and additional demographic variables (e.g., occupation, significant medical events) or cognitive scores (e.g., Matrix Reasoning (Hilsabeck & Sutker, 2009)) might notably improve the prediction of premorbid memory. Regardless of these limitations, the current results support the search for additional estimates of premorbid memory functioning, as well as their validation in healthy and impaired samples.…”

“…However, he noted that using demographic variables and other performance measures may improve the prediction of prior memory abilities. In this vein, Hilsabeck and Sutker (2009) tried to predict premorbid memory functioning in older adults with demographic variables and cognitive measures. Using multiple regression analyses, it was observed that gender and “hold” tests from the Wechsler Adult Intelligence Scale – III could be used to predict premorbid memory abilities.…”