Yuyu Zeng, PhD
Postdoctoral Research Associate, Brain, Language, & Acoustic Behavior Laboratory
University of Wisconsin-Madison
Word as speech motor planning units revealed by differential adaptation to altered auditory feedback
Syllables are historically taken as the central unit of speech motor planning. There is emerging indirect support for planning units above the syllable level, but direct experimental evidence is still lacking. We use altered auditory feedback to provide straightforwardly interpretable experimental data for words as a potential planning unit. This procedure introduces real-time alteration of speech (saying “bed” but hearing “bad”). With repetition, speakers modified their speech to receive the expected auditory signal (saying “bid” to hear the intended “bed”). In two studies, we applied opposing altered auditory feedback to investigate the word as a potential motor planning unit. In Study 1, speakers learned to produce the same syllable (e.g., “ped”) differently based on the word it belongs to (opposite changes to “pedigree” vs. “pedicure”). In Study 2, learned changes to the production of isolated syllables did not transfer to the same syllables when they were part of a multisyllabic word. Together, these studies strongly suggest the word as a speech motor planning unit.