Selective naming (and comprehension) deficits in Alzheimer's disease?
The study addresses the issue of the selective preservation of verbs in Alzheimer's disease (AD). Twenty three AD patients and age-matched controls named pictures of objects and actions and took part in a word-picture verification task. The results for picture naming revealed that both patients and controls were faster and produced more target responses for objects than actions. In the comprehension task, accuracy levels were comparable for nouns and verbs, but response times were longer for verbs. Although patients were more error prone and had longer latencies in both tasks than controls, the only qualitative difference in performance between the groups was in response to trials with semantically related foils in the word-picture verification task. Patients were particularly error prone in this condition. We conclude that the results do not provide support for the notion that verbs are selectively preserved in AD. They also do not provide conclusive evidence for claims that depressed naming and comprehension is (always) due to loss of semantic knowledge or inadequate access to semantic knowledge. Finally, we discuss the findings in relation to comparable investigations in patients with semantic dementia.
Masterson
Jackie
J
Psychology and Human Development, Institute of Education, University of London, UK. j.masterson@ioe.ac.uk
Druks
Judit
J
Kopelman
Michael
M
Clare
Linda
L
Garley
Claire
C
Hayes
Maureen
M
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications*; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D006801:Humans; D007806:Language Disorders / Q000150:complications*; D007807:Language Tests; D016555:Matched-Pair Analysis; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D012016:Reference Values; D012660:Semantics; D014705:Verbal Behavior / Q000502:physiology*