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2019 Alzheimer's Association Research Fellowship (AARF)

Assessment of Cognitive Effort in Alzheimer Disease

Does willingness to exert mental effort and motivation decline in early stage Alzheimer’s dementia?

Andrew Aschenbrenner, Ph.D.
Washington University
St. Louis, MO - United States


In early stages of Alzheimer’s, cognitive decline is subtle and is often difficult to detect. Researchers gauge cognitive performance using a variety of cognitive tests that measure mental abilities, learning, memory etc. Past studies suggest that performance on cognitive tests depends on the individual’s motivation and willingness to exert effort in the given moment, termed “cognitive effort” and may not be truly reflective of an individual’s cognitive ability. Studies also show that among individuals who demonstrate the same cognitive ability, those with higher motivation at the time of a test appear to score higher on the cognitive outcome than others. Dr. Andrew Aschenbrenner and colleagues propose to administer a way to evaluate cognition while also measuring their effort and motivation to better understand how these are linked.

Research Plan

To conduct their study, Dr. Aschenbrenner and his team will first recruit 100 middle aged and older adults from the local community. This recruitment will be facilitated by Volunteers for Health, a registry of individuals in St. Louis, who are interested in participating in research. The researchers will use a previously validated and objective test of cognitive effort called COGED (Cognitive Effort Discounting Paradigm). The COGED tool will produce a continuous measure of effort while simultaneously assessing performance on an important cognitive measure - memory. The researchers plan to use COGED repeatedly at different time points to test the individual’s effort level. This will enable Dr. Aschenbrenner to measure changes in motivation over time as well as assess the reliability of COGED.
Furthermore, the researchers plan to apply COGED to another group of participants recruited from Knight Alzheimer’s Disease Research Center to evaluate the relationship between cognitive effort and the various biological markers associated with Alzheimer’s. Dr. Aschenbrenner proposes that cognitive effort will decline with increasing Alzheimer’s-related brain changes.


If successful, the study could be used to associate outcomes from the cognitive test (COGED) with Alzheimer’s biological markers (such as beta-amyloid plaques in the brain). These results may also help with accurate detection of an individual’s true cognitive performance to enable better therapeutic interventions. The study results could also be used to evaluate the utility of “cognitive effort” as a biological marker of early changes associated with Alzheimer’s or other dementias.

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