Healthy Aging Effects on Semantic Processing of Faces and Objects

Abstract

Neurodegenerative disorders such as Alzheimer's disease (AD) and mild cognitive impairment (MCI) remain significant health and economic burdens, affecting millions worldwide. Creating affordable and accurate early diagnostic instruments for these disease states potentiates a higher quality of life for those affected by providing sufficient time for individuals to begin preventative pharmacotherapies before AD/MCI symptoms ensue. The current study aimed to utilize electroencephalogram (EEG) on a cognitively healthy population (n = 21) of varying ages (aged 20 - 72) to assess the effects of normal, healthy aging on semantic processing of faces and objects. Analysis of the results determined that age had a significant effect on two event-related potential (ERP) components, with the highest correlation attained from P600 latency at electrode Pz (= - 0.697) indicating faster semantic processing of familiar faces with increased age. Results from scalp current density (TLT) analysis supported these findings, indicating that semantic processing of familiar faces occurred quicker for older groups, however, revealed sustained cortex activation for younger groups. The findings from this study highlight potential neural biomarkers that may be used to differentiate healthy elderly populations from those affected by AD and MCI.