Mental representations of vowel features asymmetrically modulate activity in superior temporal sulcus.
Research in auditory neuroscience illustrated the importance of superior temporal sulcus (STS) for speech sound processing. However, evidence for abstract processing beyond the level of phonetics in STS has remained elusive. In this study, we follow an underspecification approach according to which the phonological representation of vowels is based on the presence vs. absence of abstract features. We hypothesized that phonological mismatch in a same/different task is governed by underspecification: A less specified vowel in second position of same/different minimal pairs (e.g. [e]) compared to its more specified counterpart in first position (e.g. [o]) should result in stronger activation in STS than in the reverse presentation. Whole-brain analyses confirmed this hypothesis in a bilateral cluster in STS. However, this effect interacted with the feature-distance between first and second vowel and was most pronounced for a minimal, one-feature distance, evidencing the benefit of phonological information for processing acoustically minimal sound differences.
Department of Language and Literature, Max Planck Institute for Empirical Aesthetics, Frankfurt, Germany; Institute of Psychology, Department of Cognitive and Biological Psychology, University of Leipzig, Germany. Electronic address: mathias.scharinger@aesthetics.mpg.de.
Mathias
M
Scharinger
Faculty of Education, Free University of Bozen-Bolzano, Italy.
Ulrike
U
Domahs
Leibniz-Institut für Wissensmedien, Tübingen, Germany.
Elise
E
Klein
Institute for Germanic Linguistics, University of Marburg, Germany.
Frank
F
Domahs
D000328:Adult; D001303:Auditory Cortex / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008297:Male; D010700:Phonetics; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*
Phonological features; Place of articulation; Precuneus; Rounding; Superior temporal gyrus; Superior temporal sulcus; Tongue height; Underspecification; fMRI