AUDITORY AND VESTIBULAR SYSTEMSPhonological categorization of vowels: A mismatch negativity studyHill, Penelope R.CA; McArthur, Genevieve M.1; Bishop, Dorothy V. M.Author Information Department of Experimental Psychology, Oxford University, South Parks Road, Oxford, OX1 3UD, UK 1 The Macquarie Centre for Cognitive Science, Macquarie University, Sydney, NSW 2109, Australia CACorresponding Author: PennyHill@OxfordHearing.com Received 5 July 2004; accepted 20 July 2004 NeuroReport: October 5th, 2004 - Volume 15 - Issue 14 - p 2195-2199 Buy Abstract There is electrophysiological evidence that phonological categorization has occurred within 100–200 ms post stimulus onset for the syllables /tae/ and /dae/, which vary in voice onset time. Using a similar paradigm, this study investigated when phonological categorization occurred for the contrast between /I/ and /ε/, using synthesized speech tokens that differed in the frequency of the first formant. Here we show that phonological categorization of these tokens has not occurred 100–200 ms after stimulus onset. However, the presence of a late mismatch negativity (350 ms after stimulus onset) indicated that phonological categorization had taken place by this time. © 2004 Lippincott Williams & Wilkins, Inc.