MAPT and Apathy: Consistently, positron emission tomography (PET) studies have reported that AD-related apathy is associated with increased Aβ accumulation in the orbitofrontal cortex (OFC) bilaterally and in the left superior frontal cortex [19] and increased p-tau accumulation in the left superior parietal cortex [20] and in the right anterior cingulate (ACC) and dorsolateral prefrontal cortices (PFC) [21].