title: Regional electroencephalogram (EEG) alpha power and asymmetry in older adults: a study of short-term test-retest reliability.
abstract: Although regional alpha power and asymmetry measures have been widely used as indices of individual differences in emotional processing and affective style in younger populations, there have been relatively few studies that have examined these measures in older adults. Here, we examined the short-term test-retest reliability of resting regional alpha power (7.5-12.5 Hz) and asymmetry in a sample of 38 active, community-dwelling older adults (M age = 71.2, SD = 6.5 years). Resting electroencephalogram recordings were made before and after a perceptual computer task. Pearson and intra-class correlations indicated acceptable test-retest reliability for alpha power and asymmetry measures in all regions. Interestingly, alpha asymmetry appeared to be less affected by the task than was alpha power. Findings suggest that alpha asymmetry may reflect more enduring, "trait-like" characteristics, while alpha power may reflect more "state-like" processes in older adults.
authors.affiliation: Department of Psychology, Neuroscience and Behaviour, McMaster University Hamilton, ON, Canada.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Mathewson
authors.affiliation: Department of Psychology, Neuroscience and Behaviour, McMaster University Hamilton, ON, Canada.
authors.forename: Ali
authors.initials: A
authors.lastname: Hashemi
authors.affiliation: Department of Psychology, Neuroscience and Behaviour, McMaster University Hamilton, ON, Canada.
authors.forename: Bruce
authors.initials: B
authors.lastname: Sheng
authors.affiliation: Department of Psychology, Neuroscience and Behaviour, McMaster University Hamilton, ON, Canada.
authors.forename: Allison B
authors.initials: AB
authors.lastname: Sekuler
authors.affiliation: Department of Psychology, Neuroscience and Behaviour, McMaster University Hamilton, ON, Canada.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Bennett
authors.affiliation: Department of Psychology, Neuroscience and Behaviour, McMaster University Hamilton, ON, Canada.
authors.forename: Louis A
authors.initials: LA
authors.lastname: Schmidt
keywords: aging; alpha power; electroencephalogram (EEG); frontal asymmetry; psychophysiology; test–retest reliability