No significant associations were observed between IAF and age for frontal (β = 0.01, SE = 0.02, t = 0.75, p = .46), central (β = 0.01, SE = 0.02, t = 0.65, p = .52), occipital (β = −0.02, SE = 0.01, t = −1.59, p = .12) and left (β = −0.03, SE = 0.02, t = −1.89, p = .06) and right (β = −0.02, SE = 0.02, t = −1.07, p = .29) temporal regions. Similarly, there were no associations between IAF and theta power for central (β = −0.02, SE = 0.98, t = −0.02, p = .98), occipital (β = −0.24, SE = 0.25, t = −0.94, p = .35) and left (β = −0.13, SE = 0.19, t = −0.70, p = .49) and right (β = −0.23, SE = 0.12, t = −1.89, p = .07) temporal regions. For the frontal region, a significant association was observed (β = −0.77, SE = 0.26, t = −2.99, p = .004). However, Cook's distance and robust regression analyses identified three observations as outlying cases.
