Effect of speech rate and complexity on sentence comprehension in Alzheimer’s disease

Abstract

ABSTRACT Previous research has not shown a benefit of slowed speech on the comprehension of sentences by persons with Alzheimer’s disease (AD). The objective of this study was to replicate and extend the findings from previous research by employing a novel speech rate manipulation that inserted strategic pauses at phrase and clause boundaries in sentences. Fourteen participants with AD were instructed to match auditorily presented sentences to one of several pictures that corresponded to the correct meaning of each sentence. The sentences varied in their speech rate and grammatical complexity. The results show that participants’ comprehension did not significantly benefit from the altered speech rate, though participants did demonstrate better comprehension of simpler than more complex sentences. The findings extend previous research by showing that even when employing a more natural method of slowing the speech signal it did not benefit AD participants’ comprehension. The results also contribute to evidence-based clinical recommendations concerning speech modifications to facilitate verbal comprehension in Alzheimer’s disease.