An Investigation of Emphatic Stress Comprehension in Adult Aphasia

Abstract

The differential effects of normal and emphatic stress on the auditory comprehension performance of 9 aphasic and 5 normal adults were assessed. As a partial replication of Pashek and Brookshire (1982), four paragraph-length stimuli were used from the original study. Each paragraph was presented twice. One version was recorded with one fact per sentence receiving normal stress, the second version with emphatic stress. Following each paragraph, subjects answered 16 "yes/no" questions about the eight target facts in each paragraph. This procedure allowed for direct comparison of performance across conditions on the same paragraph rather than on different paragraphs as in the original study. Analysis of the results revealed that the aphasic subjects demonstrated significantly better performance for stimuli presented with emphatic stress. In addition, no significant learning effect was observed over two repetitions of each paragraph. These data are interpreted as successfully replicating the findings of Pashek and Brookshire. The results suggest that emphatic stress plays an important role in auditory comprehension. However, the observed effect of emphatic stress should not be attributed solely to changes incumbent upon the stress bearing word. Alternative explanations are discussed.