On the matching of top-down knowledge with sensory input in the perception of ambiguous speech

BMC Neuroscience

Research Article

R Hannemann¹  C Eulitz¹ 

[1] Department of Linguistics, University of Konstanz, Konstanz, Germany;

关键词: Speech Perception;    Mental Lexicon;    Latency Range;    Lexical Information;    Stimulus Class;   

DOI  :  10.1186/1471-2202-11-67

 received in 2008-11-07, accepted in 2010-06-02,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundHow does the brain repair obliterated speech and cope with acoustically ambivalent situations? A widely discussed possibility is to use top-down information for solving the ambiguity problem. In the case of speech, this may lead to a match of bottom-up sensory input with lexical expectations resulting in resonant states which are reflected in the induced gamma-band activity (GBA).MethodsIn the present EEG study, we compared the subject's pre-attentive GBA responses to obliterated speech segments presented after a series of correct words. The words were a minimal pair in German and differed with respect to the degree of specificity of segmental phonological information.ResultsThe induced GBA was larger when the expected lexical information was phonologically fully specified compared to the underspecified condition. Thus, the degree of specificity of phonological information in the mental lexicon correlates with the intensity of the matching process of bottom-up sensory input with lexical information.ConclusionsThese results together with those of a behavioural control experiment support the notion of multi-level mechanisms involved in the repair of deficient speech. The delineated alignment of pre-existing knowledge with sensory input is in accordance with recent ideas about the role of internal forward models in speech perception.

【 授权许可】

CC BY   
© Eulitz and Hannemann; licensee BioMed Central Ltd. 2010