On the preservation of syntax in Alzheimer's disease. Evidence from written sentences
S. Kemper, E. LaBarge, F. R. Ferraro, H. Cheung, H. Cheung and M. Storandt
Department of Psychology, University of Kansas, Lawrence.
We examined the syntactic complexity of single written sentences elicited
from 368 adults undergoing examination for possible Alzheimer's disease.
The clause length and composition of the sentences varied with the severity
of dementia. The nondemented adults' sentences contained more propositions,
main and secondary verbs, and conjunctions than those produced by the
mildly and moderately demented adults. Sentence length in clauses,
propositional content, and the use of conjunctions and main and secondary
verbs discriminated among stages of the severity of the disease. The
present results suggest that, while dementia severity affects written
linguistic output, such output is, nonetheless, grammatic and coherent.