MAPT and Mental deterioration: Indeed, in AD cognitive decline correlates more closely with the progression of tau aggregate pathology than with the presence of amyloid‐β plaques.[10, 11, 12] However, small soluble aggregates are thought to exert potent cellular toxicity[13, 14] and appear to spread from cell to cell as a potential mechanism for the propagation of tau pathology throughout the brain.[15, 16]