Neuropsychological and resting-state electroencephalographic markers of older adult neurocognitive adaptability

Abstract

Objective: This study was undertaken to explore multimethod neurocognitive screening tools to aid in detection of older adults who may be at heightened risk of pathological cognitive decline (preclinical dementia). In so doing, this study advances the theoretical conceptualization of neurocognitive adaptability in the context of aging and dementia.

Method: This article reports original data from the baseline measurement occasion of a longitudinal study of healthy, community-dwelling older adults from the Victoria, British Columbia region. Participants were diagnosed as normal, subtle decline, or mild cognitive impairment according to actuarial neuropsychological criteria (adjusted for age only or adjusted for age and premorbid IQ). Diagnostic classification was employed to illustrate group differences in a novel metric of multi-timescale neural adaptability derived from 4-min of resting-state electroencephalographic data collected from each participant (immediately following their neuropsychological evaluation).

Results: Prior findings were replicated; adjusting raw neuropsychological test scores for individual differences in estimated premorbid IQ appeared to increase the sensitivity of standardized clinical tasks to subtle cognitive impairment. Moreover, and consistent with prior neuroscientific research, timescale-specific (i.e. at ∼12–20 ms timescales) differences in resting-state neural adaptability appeared to characterize groups who differed in terms of neuropsycholgoical diagnostic classification.

Conclusions: Recently proposed actuarial neuropsychological criteria for subtle cognitive decline identify older adults who show timescale-specific changes in resting brain function that may signal the onset of preclinical dementia. The subtle decline stage may represent a critical inflection point—partial loss of neurocognitive adaptability—on a pathological aging trajectory. These findings illustrate areas of potential future development in neurocognitive health care.

Keywords:

• Aging
• preclinical dementia
• multimethods
• electroencephalography
• multiscale sample entropy

Acknowledgments

Dedicated to Michael A. Persinger (1945 – 2018). This work was supported by Alzheimer Society Research Program/Pacific Alzheimer Research Foundation under Doctoral Award #1343. Thanks to Corson Areshenkoff and Patrick Frisby for technical assistance, and to Jacob Koudys, Jon Shepherd, and Lara Oberg for help with data collection and data entry. Extra special thanks to the participants – without whom this project would not have been possible – for their dedication and enthusiasm.

Disclosure statement

The authors declare that no actual or potential conflict of interest exerted inappropriate influence over this work.

Additional information

Funding

Dedicated to Michael A. Persinger (1945 – 2018). This work was supported by Alzheimer Society Research Program/Pacific Alzheimer Research Foundation under Doctoral Award #1343. Thanks to Corson Areshenkoff and Patrick Frisby for technical assistance, and to Jacob Koudys, Jon Shepherd, and Lara Oberg for help with data collection and data entry. Extra special thanks to the participants – without whom this project would not have been possible – for their dedication and enthusiasm