Comparison of reading and spelling in patients with probable Alzheimer's disease.

Abstract

Patients with probable Alzheimer's disease (AD) are reported to show mild, but reliable, difficulties reading aloud and spelling to dictation exception words, which have unusual or unpredictable correspondence between their spelling and pronunciation (e.g., touch). To understand the cognitive dysfunction responsible for these impairments, 21 patients and 27 age-and education-matched controls completed specially designed tests of single-word oral reading and spelling to dictation. AD patients performed slightly below controls on all tasks and showed mildly exaggerated regularity effects (i.e., the difference in response accuracy between words with regular spellings minus exception words) in reading and spelling. Qualitative analyses, however, did not demonstrate response patterns consistent with impairment in central lexical orthographic processing. The authors conclude that the mild alexia and agraphia in AD reflect semantic deficits and nonlinguistic impairments rather than a specific disturbance in lexical orthographic processing.

Oral Reading in Dementia

“…The second reading task consisted of a list of pronounceable nonwords, or pseudowords (PW's) (Glosser et al, 1999). There were 48 four to six-letter, single-syllable PW's, 24 of each of two types: (1) regular PW's (e.g., brist) had a single or invariant pronunciation and (2) ambiguous PW's (e.g., grour) contained letter combinations that had several potentially acceptable pronunciations.…”

Normal and Impaired Spelling in a Connectionist Dual-Route Architecture

“…In patients with dementia of the Alzheimer's type (DAT), who indeed present with semantic deficits, the finding of surface dysgraphia is not universal, and with disease progression nonphonologically plausible errors increase (see Graham, 2000, for review). Moreover, in DAT patients the effect of spelling regularity is only slightly enhanced in comparison to control subjects (e.g., Glosser, Grugan, & Friedman, 1999a;Glosser, Kohn, Sands, Grugan, & Friedman, 1999b).…”

Intact reversed language-dominance but exaggerated cognate effects in reading aloud of language switches in bilingual Alzheimer’s disease.

“…Highly practiced and more automatic linguistic processing tasks, such as reading, are thought to be relatively preserved (Cummings, Houlihan, & Hill, 1986; Friedman, Ferguson, Robinson, & Sunderland, 1992; Sasanuma, Sakuma, & Kitano, 1992). However, in moderate stages of cognitive impairment patients exhibit increased difficulty reading low-frequency words with irregular spelling-to-sound correspondences (e.g., Strain, Patterson, Graham, & Hodges, 1998, possibly reflecting semantic impairments, Glosser, Grugan, & Friedman, 1999), and articulation rate is decreased while proportion of pauses is increased in connected speech elicited via reading aloud (Martínez-Sánchez, Meilán, García-Sevilla, Carro, & Arana, 2013; see review in Glosser & Grossman, 2004).…”