Age, theta/beta ratios, and individual peak alpha frequency in older adults

Descriptors: EEG, Theta/Beta Ratio, Peak Alpha

Prior research has found the ratio of fronto‐central Theta (4–7 Hz) and Beta oscillations (13–30 Hz; Theta/Beta Ratio [TBR]) is negatively correlated with attentional control, reinforcement learning, executive function, and age. While TBRs have been found to decrease with age in adolescents and undergraduate samples, theta has been found to increase with age. Moreover, age‐related decreases in individual peak Alpha frequency (IPAF) may be artifactually inflating the Theta component of TBRs. Collectively, these factors lead to an incomplete understanding of how TBRs predict a variety of constructs across the lifespan, particularly in older adults. Here, we present a preregistered analysis of data from the MIDUS 2 Neuroscience Project, reporting on cross‐sectional associations between resting TBRs, age, and IPAF (n = 319; age 36–84, M = 55.28, SD = 11.10). We found that age was negatively correlated with TBRs and IPAF, such that older participants had lower TBRs and lower IPAF. Although we also observed a significant negative correlation between Theta and IPAF, there was limited evidence for a correlation between Theta and age. Notably, the correlation between TBR and age remained after controlling for IPAF. Our results replicate observations that TBR and IPAF are cross‐sectionally associated with age, and show that the decreases observed in adolescents and young‐adults are also seen across adulthood into older age. Our results also show that age‐related decreases in TBR are not due to age‐related decreases in IPAF.

Funding: The MIDUS Neuroscience Project was funded by the National Institute on Aging (P01‐ AG020166, U19‐AG051426) and by the Waisman Intellectual and Developmental Disabilities Research Center (U54‐HD090256) awarded by the National Institute of Child Health and Human Development.