Open AccessVowel sound extraction in anterior superior temporal cortex
Author(s) -
Obleser Jonas,
Boecker Henning,
Drzezga Alexander,
Haslinger Bernhard,
Hennenlotter Andreas,
Roettinger Michael,
Eulitz Carsten,
Rauschecker Josef P.
Publication year - 2006
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.20201
Subject(s) - formant , auditory cortex , vowel , functional magnetic resonance imaging , psychology , perception , speech perception , temporal cortex , neurocomputational speech processing , audiology , speech recognition , neuroscience , computer science , medicine
We investigated the functional neuroanatomy of vowel processing. We compared attentive auditory perception of natural German vowels to perception of nonspeech band‐passed noise stimuli using functional magnetic resonance imaging (fMRI). More specifically, the mapping in auditory cortex of first and second formants was considered, which spectrally characterize vowels and are linked closely to phonological features. Multiple exemplars of natural German vowels were presented in sequences alternating either mainly along the first formant (e.g., [u]‐[o], [i]‐[e]) or along the second formant (e.g., [u]‐[i], [o]‐[e]). In fixed‐effects and random‐effects analyses, vowel sequences elicited more activation than did nonspeech noise in the anterior superior temporal cortex (aST) bilaterally. Partial segregation of different vowel categories was observed within the activated regions, suggestive of a speech sound mapping across the cortical surface. Our results add to the growing evidence that speech sounds, as one of the behaviorally most relevant classes of auditory objects, are analyzed and categorized in aST. These findings also support the notion of an auditory “what” stream, with highly object‐specialized areas anterior to primary auditory cortex. Hum. Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.