METALINGUISTIC JUDGMENTS IN NORMAL AGING AND ALZHEIMERS-DISEASE

This study compared sentence acceptability judgments from young and he althy older adults and older adults with dementia due to probable Alzh eimer's disease. Two types of sentences were contrasted: one type invo lved contrasts among verb alternations in which semantic distinctions between verbs regulate the acceptability of phrase structure variation s; the second type involved contrasts among directional transformation s in which constraints on the movement of noun phrases determine the l inear order of main and embedded clauses. The primary findings were th at metalinguistic judgments by healthy alder adults as wed as those wi th probable Alzheimer's reflected processing demands on working memory . In addition, metalinguistic judgments by adults with probable Alzhei mer's reflected the breakdown of semantic information about verbs.