Preserved word-stem-completion priming of semantically encoded information in Alzheimer's disease.

Alzheimer's disease (AD) patients and normal elderly control subjects completed 80 standardized sentence frames with single words, yielding a measure of semantic memory. Memory for best fit sentence endings was then tested either explicitly, with a forced-choice recognition task, or implicitly, with a word-stem-completion task. The patients completed fewer sentences with best fit word endings than did the control subjects. Explicit retention was markedly defective in the AD group, but word-stem completion was normal. The preserved word-stem completion in AD is discussed in terms of encoding operations and transfer-appropriate processing.