Contextual facilitation of lexical processing in Alzheimer's disease: intralexical priming or sentence-level priming?

Studies of semantic priming (facilitation of lexical processing by a prior semantic context) suggest that semantic-memory structure remains intact in Alzheimer's disease (AD). Recently, however, it has been claimed that the priming produced by single-word primes reflects merely the facilitation of preexisting lexical associations (intralexical priming) and thus reveals nothing about semantic memory in AD. Other studies showing normal priming in AD have used sentences as primes. However, intralexical priming originating from individual words within the sentence might also account for this type of contextual priming. This possibility was examined by reanalyzing previous sentence-priming results using data only from those trials where there was little likelihood of intralexical priming. This did not change the previous pattern of priming facilitation, suggesting that the normal sentence priming found in AD patients derives from the message conveyed by the sentence as a whole, rather than from simple intralexical associations.