interventions targeting positive affect could have potential in mitigating pathological processes associated with cognitive and functional decline through increasing flexible and adaptive responses (e.g. thought-action repertoires) to environmental demands and/or optimizing cerebral glucose metabolism within these particular brain regions. Of course, this is highly speculative, and warrants examination with more sophisticated modeling techniques and measures to further clarify the causal relationships between these variables. There are potential limitations of our study that deserve mentioning. First, because over half the participants in this study have a family history of AD (66.9%), were late middleaged (m ¼ 59.29 yrs-old), highly educated (m ¼ 16.97 yrs) and predominantly Caucasian (97.0%), the generalizability of our results is limited and would benefit from replication in more diverse samples. Second, while we included a measure of perceived health, which has been shown to attenuate the association between happiness and all-cause mortality (Liu et al., 2016), we did not examine a variety of specific psychological (e.g. personality, coping style), health (e.g. cardiovascular, endocrine, exercise) and social factors (e.g. social stress and support, income) that may be associated with positive affect (Lyubomirsky et al., 2005). Lastly, we speculate based on the literature regarding possible connectivity between regions, thus future analyses employing connectivity methods for FDG-PET **data** would be useful.