We provide rigorous psychometric evidence for distinct patterns of cognitive impairment for Alzheimer's disease (AD) and cerebral infarctions using 440 participants from the Religious Order Study. Latent variable models were used to decompose the effects of AD pathology and cerebral infarctions assessed at autopsy on overall cognition and specific neuropsychological tests at one and five years prior to death. Results support clinical and univariate psychometric analyses that memory impairment is more pronounced in AD, and executive impairment is more pronounced in the presence of cerebral infarctions. These specific effects are subtle relative to the stronger associations of both AD neuropathology and cerebral infarctions with overall levels of cognitive impairment.