MAPT and memory impairment: Thus, our results on the lack of relationship between PiB retention and the decline of cognitive function are also consistent with previous reports (Jack et al., 2009; Villemagne et al., 2011) and may support the view that tau deposition and astrogliosis/neurodegeneration, rather than Aβ pathology, have a close relationship with cognitive decline, predominantly memory impairment, in AD.