Metacognition, cortical thickness, and tauopathy in aging

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Self-appraisal of cognitive performance is crucial for daily functioning in aging.
• Understanding appraisal discrepancy (difference between perceived and actual performance) is key in older adults.
• Alzheimer's disease (AD) pathology, including amyloid and tau, impacts cognition and self-awareness.

Purpose of the Study:

• To investigate self-appraisal and appraisal discrepancy in cognitively healthy older adults.
• To examine the relationship between self-appraisal, appraisal discrepancy, and brain structure (cortical thickness).
• To explore the association with Alzheimer's disease biomarkers (amyloid and tau).

Main Methods:

• 151 cognitively healthy older adults underwent neuropsychological testing and structural MRI.
• A subset (N=66) received amyloid-PET and tau-PET imaging.
• Analysis correlated self-appraisal, appraisal discrepancy, cortical thickness, and AD biomarker levels.

Main Results:

• Worse cognitive performers exhibited lower self-appraisal but still overestimated their abilities (Dunning-Kruger effect).
• Greater appraisal discrepancy (overestimation) correlated with reduced cortical thickness in specific brain regions (temporal, fusiform, cingulate).
• Lower self-appraisal was associated with increased tau pathology in the entorhinal and inferior temporal cortices.

Conclusions:

• Overestimation of cognitive performance may relate to structural brain atrophy independent of AD pathology.
• Lower self-appraisal could indicate early behavioral changes linked to AD pathology, suggesting subjective cognitive decline.
• Distinct relationships exist between self-appraisal, appraisal discrepancy, brain structure, and AD biomarkers in aging individuals.