EXPLORING THE LOSS OF SEMANTIC MEMORY IN SEMANTIC DEMENTIA - EVIDENCEFROM A PRIMED MONITORING STUDY

An on-line primed monitoring study was used in an exploration of the n ature of semantic memory loss in a patient (P.P.) with semantic dement ia who showed a profound semantic impairment on a range of off-line ta sks. Priming for pairs of words taken from a common category (e.g., ca t-dog, spade-rake, ruby-emerald) was contrasted with that for word pai rs from different categories that were related functionally (e.g., sha mpoo-hair, broom-poor, theater-play). Control participants showed robu st priming for both types of semantic relation. P.P., in contrast. sho wed a normal priming effect for the functionally related conditions bu t no priming for category coordinates. This result suggests that P.P.' s semantic memory loss cannot be explained solely as a loss of stored representations or as a problem with deliberate controlled access to t hat information. Rather, elements of both explanations apply for diffe rent kinds of semantic information.