14th International Congress of Phonetic Sciences (ICPhS-14)
San Francisco, CA, USA
The present study investigated brain hemisphere lateralization effects with respect to the encoding of dynamic aspects of the acoustic speech signal. Using a whole-head device, auditory evoked magnetic fields were recorded in response to vowels as well as syllable-like structures differing either in direction or in duration of the formant transients. All trials used a synthesized vowel as a template against which the deviants had to be matched. Both the N1m component and difference waves between the magnetic fields to standard and respective rare events (MMNm) were calculated. (a) Vowel mismatch (/a/ against /e/) resulted in enlarged N1m amplitude reflecting, most presumably, peripheral adaptation processes. (b) As concerns syllable-like structures differing in their dynamic characteristics, only the shortest transient duration (= 10 ms) elicited a significant lateralization effect toward the left hemisphere. Thus, pre-attentive acoustic pro- cessing already yields lateralization effects and does not seem to depend on encoding of linguistic categories.
Bibliographic reference. Mathiak, Klaus / Hertrich, Ingo / Lutzenberger, Werner / Ackermann, Hermann (1999): "Pre-attentive processing of consonant-vowel syllables at the supratemporal plane: a whole-head MEG study", In ICPhS-14, 2077-2080.