MAPT and Alzheimer disease: The pathological accumulation of tau is associated with the spatial and episodic memory impairments that characterize both healthy aging (Crary et al., 2014; Hirni et al., 2016; Khan et al., 2014; Maass et al., 2019; Reagh et al., 2018) and Alzheimer's disease (AD) (Backman et al., 2004; Dubois et al., 2007; McKhann et al., 2011).