RETRIEVAL FROM SEMANTIC MEMORY AND ITS IMPLICATIONS FOR ALZHEIMERS-DISEASE

In 3 experiments, participants generated category exemplars (e.g., kin ds of fruits) while a voice key and computer recorded each response la tency relative to the onset of responding. In Experiment 1, mean respo nse latency was faster when participants generated exemplars from smal ler categories, suggesting that smaller mental search sets result in f aster mean latencies. In Experiment 2, a concurrent secondary task inc reased mean response latency, suggesting that slowed mental processing results in slower mean latencies. In Experiment 3, the mean response latency of Alzheimer's participants was faster than that of elderly co ntrols, which is consistent with the idea that the semantic memory imp airments of Alzheimer's disease patients stem primarily from a reducti on in available items (as in Experiment 1) rather than retrieval slowi ng (as in Experiment 2).