Intentional and automatic measures of specific-category effect in the semantic impairment of patients with Alzheimer's disease.
The breakdown of semantic knowledge relative to living and non-living categories was studied in patients with Alzheimer's disease (AD). The same living and non-living items were used in a semantic battery and in a semantic priming paradigm exploring automatic access to the semantic system. Although AD patients showed a semantic deficit on the intentional semantic battery, they demonstrated normal semantic facilitation on the priming task. In the AD group as a whole, the semantic impairment did not preferentially affect the living category either in the intentional or automatic condition. Instead, a prevalent deficit for the living category was found in three AD patients (14% of the group) on the intentional semantic tasks, but not on the automatic one. These findings support the view that the category effect may not be a generalised phenomenon in AD but may be restricted to a limited number of patients. The intentional/automatic dissociation of the semantic breakdown demonstrated by AD patients is discussed in relation to different theories regarding the organisation of semantic memory.
Perri
Roberta
R
IRCCS Fondazione Santa Lucia, Via Ardeatina 306, 00179 Rome, Italy. r.perri@hsantalucia.it
Carlesimo
Giovanni A
GA
Zannino
Gian Daniele
GD
Mauri
Marco
M
Muolo
Barbara
B
Pettenati
Carla
C
Caltagirone
Carlo
C
D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology* / Q000523:psychology; D001245:Association Learning / Q000502:physiology*; D002965:Classification; D005260:Female; D006801:Humans; D007600:Judgment; D016015:Logistic Models; D008297:Male; D016555:Matched-Pair Analysis; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D010363:Pattern Recognition, Automated; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D012044:Regression Analysis; D012660:Semantics; D014705:Verbal Behavior / Q000502:physiology; D014706:Verbal Learning / Q000502:physiology*