Impairments to either perceptual or word-retrieval
processes have been hypothesized to explain confrontation
naming impairments in patients with Alzheimer's disease
(AD). This study measured the effects of structural similarity,
which affects perceptual processing, and name frequency,
which affects word retrieval, on naming latency and accuracy
in 16 AD patients and 16 age-matched controls. AD patients
named pictures more slowly and made more errors than control
participants. Their naming accuracy was disproportionately
affected by name frequency, but not by structural similarity.
The findings indicate that the processing of structural
properties of objects is unaffected in early-stage AD,
and suggest that word-retrieval impairments underlie the
naming deficit in AD. (JINS, 1999, 5,
659–667.)