Quality of spelling breakdown in Alzheimer's disease is independent of disease progression

There is a convergence of evidence from recent studies that spelling is impaired in Alzheimer's Disease (AD) relative to normal aging. However, the literature is more divided over whether there is a logical pattern in spelling deterioration with disease progression. The present study reviewed performance of participants with mild AD, moderate AD, and control participants on a written and oral spelling task. Results suggest that spelling in individuals with AD is impaired relative to controls. Comparison between those with mild AD and moderate AD failed to find evidence of a logical pattern of deterioration. We further examined the effects of word characteristics on spelling performance. Although increasing in quantity with disease progression, analysis of quality of spelling errors reveal a multi-componential disruption of spelling ability, which is independent of disease progression.