Naming without picture comprehension? Apropos the oral naming and semantic comprehension of pictures by patients with Alzheimer's disease

There is overwhelming clinical and experimental evidence that patients with dementia of the Alzheimer's type (DAT) suffer from impairment in the ability to name pictures. In spite of some studies which underline the importance of perceptual factors in picture naming by dementing patients (see, for example, Huff et al. 1986, Kirshner et al. 1987, Martin and Fedio 1983) there is general agreement that DAT's naming impairment mainly reflects impaired processing of semantic information (see, for example, Chertkow at nf. 1989, Huff et af. 1986, Margolin et al. 1990). However, recently it was observed that naming impairment can occur post-semantically; that is in the presence of accurate identification of semantic features (Miller Sommers and Pierce 1990). Also, in one (so far exceptional) case description spared naming without comprehension was reported in a patient with degenerating illness (Kremin 1986).