The Role of Fundamental Frequency and Duration in the Perception of Linguistic Stress by Individuals With Brain Damage

Two tests of the ability of individuals with left-hemisphere damage (LHD) and right-hemisphere damage (RHD) and non-brain-damaged participants to identify phonemic and emphatic stress contrasts were undertaken. From a set of naturallyproduced base stimuli, two additional stimulus sets were derived. In one, fundamental frequency (F₀) cues to stress were neutralized, whereas in the other duration cues were effectively neutralized. Results demonstrated that individuals with LHD were unable to identify phonemic stress contrasts with better-thanchance accuracy; individuals with RHD performed worse than normal participants but significantly better than the patients with LHD—particularly with the original full-cue stimuli. All groups performed better on the emphatic stress subtest, with the scores of only the patients with LHD at chance level for the F₀-neutralized stimuli. The findings are considered in relation to hypotheses concerning the hemispheric lateralization of prosodic processing, particularly with respect to a hypothesis that posits differential lateralization for specific acoustic parameters.

KEY WORDS: prosody, cerebral, dominance, speech perception, brain damage

Submitted on November 20, 1996
Accepted on August 19, 1997