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Previous studies have shown that in the so-called opaque languages (those in which spelling does not correspond to pronunciation), there are relatively independent routes for lexical and nonlexical processing, that is, for words and nonwords, both in spoken and in written language. On the other hand, in the so-called transparent languages (those in which pronunciation corresponds to written forms), empirical evidence is scarcer. In this study of a neurological patient (parieto-temporal lesion), speaker of a transparent language (Spanish) showing a specific deficit in nonlexical reading processing, linguistic analysis for words was relatively preserved. This finding suggests the use of various routes in the processing of transparent languages.

Recent modifications of the lexical model of oral reading make the prediction that under conditions where sublexical reading processes alone cannot achieve the target pronunciation (i.e., when words have exceptional spellings or when sublexical processes are impaired), patients with severe semantic impairment should have more difficulty reading aloud semantically impaired words than semantically retained words. In a battery of lexical-semantic and reading tasks, two neurologically normal control subjects and two subjects with probable Alzheimer's disease (AD) and only moderate semantic impairment read aloud all words accurately. One AD subject with severe semantic impairment was impaired in word reading but demonstrated no difference in reading words with regular and exceptional spellings. Another AD subject with severe semantic impairment read aloud without error virtually all regular and exception words. Neither severely impaired AD subject demonstrated any relationship between oral reading accuracy and semantic knowledge of exception words. These findings support a model of word reading incorporating lexical, nonsemantic processes by which lexical orthographic input representations directly activate lexical phonological output representations without the necessity of semantic mediation.

Background: Pre-morbid intelligence level is routinely assessed in Alzheimer's disease using the National Adult Reading Test (NART). This practice is based on the assumption that pronunciation of irregular words remains unaffected by the disease process. Recent reports have suggested that reading ability may become compromised in moderately demented subjects., Method: Sixty-eight probably Alzheimer patients were classified into stages of severity (minimal, mild and moderate) using the Mini-Mental State Examination (MMSE). NART and demographic equations were used to estimate pre-morbid ability., Results: A significant correlation emerged between dementia severity and reading ability, NART v. MMSE scores, r = 0.46, P < 0.01. When the total sample was subdivided into moderate, mild and minimal subgroups, significant between-group differences emerged, despite the groups being well matched for age, sex, and years of full-time education. Pre-morbid IQ, as estimated by demographic regression equations, did not correlate with dementia severity., Conclusion: NART performance is compromised in moderate Alzheimer disease, and the measure provides a serious underestimate of pre-morbid IQ in patients with an MMSE of 13 or less.

The aim of this study was to investigate whether reading is a preserved ability in patients suffering from dementia, as was first suggested by Nelson and McKenna (1975). The 57 patients included in the study had possible or probable Alzheimer's disease or similar degenerative conditions and were assessed longitudinally. Their performance on the National Adult Reading Test [(NART); Nelson, 1982, 1991] is compared to that on a shortened version of the WAIS-R. It is found that although performance on the NART does decline gradually over time, the deterioration on formal tests of IQ is more rapid and more severe. It seems that the decline in reading across the group is due to those patients who have a lower verbal IQ (VIQ) than performance IQ (PIQ). It is concluded that generally the NART can be used as a predictor of the premorbid intellectual functioning of a patient with dementia, given that the VIQ is greater than PIQ.

We document the unexpected dissociation of preserved reading skills in a patient with severely impaired semantic memory. The common co-occurrence between impairment of word meaning and surface dyslexia has not been observed. The patient (hereafter called DRN) had marked naming and word comprehension difficulties. A strong word frequency effect was observed on tests of word comprehension but was absent in a test of word reading. DRN's ability to read both regular and exception words that he failed to comprehend was remarkably well preserved. We will argue that these findings provide further support for the independence of semantic and phonological processing.

A case is reported in which mercury intoxication produced visual symptoms with an unusual compensation. The similarity of this patient to Schn., a much reported neuropsychiatric case, was striking and prompted correlation of the two cases. Experimental psychological studies performed on the present case provide a basis for an understanding of both cases.