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Abstract:
The present auditory study aims at identifying ERP correlates
for the processing of both sentence accents as such and their
compatibility relative to a context question (information
structure). The spoken German sentence material is based on that
introduced by Steinhauer, Alter and Friederici (1999) but varies
the positions of accents (as indicated by capitals in the examples
below). Due to the wide focus in context-free utterances with
'neutral intonation', sentence accents in the Steinhauer et al.
study were dependent on the syntactic structure only:
A. Peter verspricht Anna zu ARBEITEN und das Buero zu putzen
Peter promises Anna to WORK and to clean the office
B. Peter verspricht ANNA zu entlasten und das Buero zu putzen
Peter promises to support ANNA and to clean the office
In the present study, all sentences were preceded by context
questions establishing a narrow focus on one sentence constituent
such that only the corresponding accentuation pattern provided an
appropriate answer. The following example illustrates both an
appropriate and an inappropriate answer given the context
question:
Question B1 (=sentence type B, focus on NP2):
WEM verspricht Peter zu entlasten und das Buero zu putzen?
(WHOM does Peter promise to support and to clean the office?)
Compatible answer (B1):
Peter verspricht ANNA zu entlasten und das Buero zu putzen.
(Peter promises to support ANNA and to clean the office.)
Incompatible answer (B2):
Peter verspricht Anna zu ENTLASTEN und das Buero zu putzen.
(Peter promises to SUPPORT Anna and to clean the office.)
Acoustic analyses of the 48 speech signals in each condition
confirm that the respective prosodic patterns are reflections of
the information structure rather than the syntactic structure. Note
that incompatible answers violate the required information
structure in two ways: (1) they do not provide the required accent
on the element in focus and (2) they contain an inappropriate
accent. 22 undergraduate students participated in this experiment
and judged the prosodic compatibility of questions and answers.
Preliminary ERP data suggest that in compatible answers, lexical
elements carrying the respective accent elicit a centro-parietal
positivity. The ERP patterns for incompatible answers appear to be
more complex. Depending on both the type of violation and the
position in the sentence we observed either a negative slow wave or
a biphasic sequence of components. The nature of the ERPs will be
discussed in the context of prosodic processing models taking into
account the particular role of information structure in every-day
conversation.
Steinhauer, K., Alter, K. & Friederici, A.D. (1999) Brain
responses indicate immediate use of prosody in natural speech
processing. Nature Neuroscience, 2, 191-196.
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