Exaggerated reaction to novelty as a predictor of incipient cognitive decline among community-dwelling older adults.

OBJECTIVE: The ability to detect covert markers of incipient cognitive decline among older adults before cognitive decline becomes overtly evident on traditional cognitive tests represents an important topic of research. Exaggerated reactions to novelty, reflected in novelty-induced increases in action planning latencies ("novelty effect"; NE) and low openness to experience (openness), have been previously associated with incipient cognitive decline among older adults who appeared cognitively normal at baseline. The purposes of the present study were to extend prior research on the utility of these markers by examining whether (a) NE and openness each predict cognitive change uniquely, and (b) whether these indices predict cognitive change above and beyond measures of memory, executive functions, processing speed/efficiency, premorbid IQ, and depressive symptoms.

METHOD: Sixty-one cognitively normal community-dwelling older adults were administered a battery of tests assessing the relevant constructs at baseline and one-year follow up. Changes in cognitive status were assessed using the Demetia Rating Scale, 2nd Edition, NE was assessed using the Push-Turn-Taptap task (an electronic motor sequence learning task), and openness using the NEO Personality Inventory-Revised. The Test of Premorbid Functioning, and subtests from Repeatable Battery for the Assessment of Neuropsychological Status, Delis-Kaplan Executive Function System, and Wechsler Adult Intelligence Scale, 4th Edition, were used for additional assessment of baseline cognition. Depressive symptoms were assessed using the Geriatric Depression Scale.

RESULTS: Results confirmed our hypothesis that both NE and openness contribute to prediction of cognitive change beyond baseline cognition and depressive symptoms, but none of the covariates (i.e., depression, executive functions, processing efficiency, or memory) themselves contributed to the model. NE and openness each contributed unique variance and were independent of each other.

CONCLUSIONS: Openness and NE have the potential to provide evidence-based methods for estimating risk of future cognitive change in persons with currently normal standardized test scores.