Poster E85, Thursday, August 22, 2019, 3:45 – 5:30 pm, Restaurant Hall
Localization of gap-filler integration and garden-path effect of Chinese relative clause
Yanyu Xiong1, Aina Puce1, Sharlene Newman1;1Indiana University Bloomington
The grammatical features of Chinese relative clauses offer the possibilities of not only investigating gap-filler dependency by itself, but also how the hierarchical syntactic integration interacts with ambiguous sentence context. Our previous ERP study has found that at the relative marker de, an early left anterior negativity for the gap-filler integration effect (110-220ms) was followed by a left-lateralized negativity for the context effect (411-441ms) and a late centro-posterior positivity for the garden-path effect (540-620ms) (Xiong, Dekydtspotter & Newman, 2019). Although the temporal information reveals that gap-filler integration is modulated by sentence context in a highly dynamic manner, the neural sources of the modulation have not been identified. The present study used the boundary element method to localize the neural generators of the processes. The distributed dipole source localization was performed on the functional EEG data with the volume conduction model and source model constructed based on the MRI anatomical image of the subjects. The participants were presented with subject-gap and object-gap relative clauses either modifying the subject or object of the matrix sentences in the Rapid Serial Visual Presentation (RSVP) paradigm. The results show that between 100-200ms after the word onset of the relative marker de, object-gap relative clauses evoke greater activation in the left mid-lateral prefrontal cortex with the maximum dipole strength at the inferior frontal junction. The left-lateralized negativity of the context effect was localized at the left anterior temporal lobe between 250-350ms, which is earlier than our previous finding. In the time window between 500-600ms, the garden path effect of object-gap object-modifying relative clauses elicited more activation in the left inferior parietal cortex (including supramarginal gyrus and angular gyrus) and the fusiform gyrus. The results suggest that the left mid-lateral prefrontal cortex, as involved in a network of working memory system (Nee, et al., 2012), supports gap-filler integration in terms of maintaining and retrieving the unsolved constituents. Different from the previous report of N400 effect localized in the left superior temporal lobe (Service, et al. 2007), our finding reveals that the processing of sentence context is supported by the anterior temporal lobe in an earlier time window, indicating that the computation of phrase structure beyond the clausal level also relies on the information transferred from the anterior temporal cortex to the frontal cortex (Grodzinsky & Friederici, 2006). In addition, the garden-path effect was found to be supported by the left inferior parietal cortex and the fusiform gyrus in the late time window of de, suggesting that syntactic-semantic integration may be implemented to solve the ambiguity.
Themes: Reading, Syntax
Method: Electrophysiology (MEG/EEG/ECOG)