“…Critically, the basal forebrain emerges as one of the first brain regions to show neuropathology in association with early asymptomatic or prodromal phases of neurodegenerative diseases such as AD (Arendt, Brückner, Morawski, Jäger, & Gertz, 2015;Mesulam, Shaw, Mash, & Weintraub, 2004;Nie et al, 2017;Schmitz et al, 2016;Schmitz et al, 2018;Teipel et al, 2014;Yi et al, 2016), PD (Bohnen & Albin, 2011;Zeighami et al, 2015), and LBD (Grothe et al, 2014). Emerging evidence supports the use of resting-state fMRI as an imaging biomarker of neurodegenerative diseases (Cope et al, 2018;Hampton et al, 2020;Hohenfeld, Werner, & Reetz, 2018;Wisch et al, 2020) suggesting that in early, preclinical phases of neurodegenerative diseases, moment-to-moment variability in BOLD signal at rest may be related to the load of neurodegeneration associated neuropathology (Millar et al, 2020), and may signal either abnormalities in neurovascular coupling (Hillman, 2014;Solis, Hascup, & Hascup, 2020) or alterations in functional connectivity specifically associated with the basal forebrain (Chiesa et al, 2019;Wang, Belden, Hanser, Geddes, & Loui, 2020).…”