Using a response-priming procedure, five experiments examined the effects of vowel similarity on the motor programming of spoken syllables. In this procedure, subjects prepared to produce a pair of spoken syllables as rapidly as possible, but sometimes had to produce the syllables in reverse order instead. The spoken responses consisted of consonant-vowel-consonant (CVC) syllables whose medial vowels were /i/, /I/, /λ/, and /α/. Performance was measured as a function of the phonetic relationship between the vowels in a syllable pair. Longer response latencies occurred for syllable pairs that contained similar vowels (e.g., /i/ and /I/) than for syllable pairs that contained dissimilar vowels (e.g., /i/ and /λ/). This inhibitory vowel-similarity effect occurred regardless of whether the initial consonants of the syllables in a pair were the same or different. However, it decreased substantially when the final consonants of the paired syllables were different. These results suggest that a lateral-inhibition mechanism may modulate the motor programming of vowels during speech production. They also provide evidence for the integrity of vowel-consonant (VC) subunits in syllables.
Bibliographical noteFunding Information:
This research was supported by Grant BNS 82-06809 from the National Science Foundation to the University of Michigan, David E. Meyer, Principal Investigator. Ban Yaniv was supported by graduate fellowships from the Hebrew University and the University of Michigan. P. C. Gordon was supported by Grant 87-305 from the Air Force Office of Scientific Research. We thank Wendy Huey for valuable assistance in preparing this manuscript. Correspondence regarding this article and reprint requests should be addressed to: David E. Meyer, Human Performance Center, Dept. of Psychology, University of Michigan, 330 Packard Rd., Ann Arbor, MI 48104.