Priming in perceptual identification of pseudowords is normal in Alzheimer's disease

Patients with Alzheimer's disease (AD) have deficits in recall and recognition memory, and show dissociable performance in repetition priming tasks: They exhibit impaired priming in word-completion and word-generation tasks, but normal priming is perceptual identification of words. In order to examine whether AD patients can show normal priming with novel, unfamiliar stimuli, the present study examined their performance in perceptual identification of pseudowords. Despite impaired recognition memory performance, AD patients showed normal priming in perceptual identification of pseudowords. These results extend the boundaries of intact repetition priming in AD, demonstrating that such priming is not limited to stimuli that are pre-morbidly represented in long-term knowledge. Preserved repetition priming in AD may reflect the operation of perceptual processes localized to posterior visual circuits that are relatively spared in AD.