Paper Info
Title
Lexical influences on speech perception: A Granger causality analysis of MEG and EEG source estimates
Abstract
Behavioral and functional imaging studies have demonstrated that lexical knowledge influences the categorization of perceptually ambiguous speech sounds. However, methodological and inferential constraints have so far been unable to resolve the question of whether this interaction takes the form of direct top–down influences on perceptual processing, or feedforward convergence during a decision process. We examined top–down lexical influences on the categorization of segments in a /s/-/∫/ continuum presented in different lexical contexts to produce a robust Ganong effect. Using integrated MEG/EEG and MRI data we found that, within a network identified by 40 Hz gamma phase locking, activation in the supramarginal gyrus associated with wordform representation influences phonetic processing in the posterior superior temporal gyrus during a period of time associated with lexical processing. This result provides direct evidence that lexical processes influence lower level phonetic perception, and demonstrates the potential value of combining Granger causality analyses and high spatiotemporal resolution multimodal imaging data to explore the functional architecture of cognition.
Year
DOI
Venue
2008
10.1016/j.neuroimage.2008.07.027
NeuroImage
Keywords
Field
DocType
electroencephalography,top down,magnetoencephalography,speech perception,magnetic resonance imaging,granger causality,functional imaging,brain mapping
Categorization,Cognitive psychology,Psychology,Functional imaging,Speech recognition,Speech perception,Cognition,Supramarginal gyrus,Perception,Magnetoencephalography,Electroencephalography
Journal
Volume
Issue
ISSN
43
3
1053-8119
Citations 
PageRank 
References 
21
1.34
13
Authors
4
Name
Order
Citations
PageRank
David W. Gow1231.77
Jennifer A. Segawa2211.34
Seppo P. Ahlfors3897.59
Fa-Hsuan Lin424624.33