Our results also indicate that APOEε4 is associated with neural changes in youth, paralleling findings observed in older individuals with AD. We found that APOEε4 was associated with decreased intercept of LFC alpha EEG coherence in males and decreased RFC alpha EEG coherence in females. A systematic review of studies of EEG coherence in Alzheimer’s disease (Fischer et al., 2023) found strong evidence of decreased alpha EEG coherence among individuals with AD compared to controls, with effects most pronounced in left frontal regions. There is also evidence that APOEε4 carriers have decreased alpha EEGc in frontal regions (Jelic et al., 1997), as well as changes in other EEG measures, such as more pronounced decreases in alpha EEG power (Ponomareva, Korovaitseva, & Rogaev, 2008) and increased EEG complexity (Gutiérrez-de Pablo et al., 2020). However, existing studies of APOEε4 and EEG phenotypes have typically used smaller (N<100) cross-sectional studies in older adults. Thus, our finding that APOEε4 was associated with decreased intercept but increased slope in adolescence provides a novel contribution to our understand of the way these associations may change over
