Cerebral Cortex Advance Access originally published online on November 10, 2008
Cerebral Cortex 2009 19(7):1493-1503; doi:10.1093/cercor/bhn187
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Feature Article |
Retrieval and Unification of Syntactic Structure in Sentence Comprehension: an fMRI Study Using Word-Category Ambiguity
1 F.C. Donders Centre for Cognitive Neuroimaging, 6500 HB Nijmegen, the Netherlands, 2 Cognitive Psychology Unit, Leiden University, 2311 EZ Leiden, the Netherlands, 3 Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, the Netherlands
Address correspondence to Tineke Snijders, F.C. Donders Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Box 9101, 6500 HB Nijmegen, The Netherlands. Email: tineke.snijders{at}fcdonders.ru.nl.
Sentence comprehension requires the retrieval of single word information from long-term memory, and the integration of this information into multiword representations. The current functional magnetic resonance imaging study explored the hypothesis that the left posterior temporal gyrus supports the retrieval of lexical-syntactic information, whereas left inferior frontal gyrus (LIFG) contributes to syntactic unification. Twenty-eight subjects read sentences and word sequences containing word-category (noun–verb) ambiguous words at critical positions. Regions contributing to the syntactic unification process should show enhanced activation for sentences compared to words, and only within sentences display a larger signal for ambiguous than unambiguous conditions. The posterior LIFG showed exactly this predicted pattern, confirming our hypothesis that LIFG contributes to syntactic unification. The left posterior middle temporal gyrus was activated more for ambiguous than unambiguous conditions (main effect over both sentences and word sequences), as predicted for regions subserving the retrieval of lexical-syntactic information from memory. We conclude that understanding language involves the dynamic interplay between left inferior frontal and left posterior temporal regions.
Key Words: integration left inferior frontal gyrus lemma retrieval parsing temporal lobe