Presentation
Search Abstracts | Symposia | Slide Sessions | Poster Sessions | Lightning Talks
An EEG investigation into early syntactic processing: A rapid parallel visual presentation study of agreement and WH-dependencies in English
There is a Poster PDF for this presentation, but you must be a current member or registered to attend SNL 2023 to view it. Please go to your Account Home page to register.
Poster D120 in Poster Session D, Wednesday, October 25, 4:45 - 6:30 pm CEST, Espace Vieux-Port
Donald Dunagan1, Dustin A Chacón1; 1University of Georgia
The majority of research and theorizing in language processing assumes that language is understood word-by-word. However, during naturalistic reading, readers make use of information from multiple words in parallel (Schotter, Angele, & Rayner, 2011; Snell & Grainger, 2019). Findings from the rapid parallel visual presentation paradigm (RPVP), where multi-word sentential stimuli are briefly presented, demonstrate that sentence recall is more accurate when the stimuli are semantically congruent (Asano & Yokosawa, 2011) and syntactically well-formed (Snell & Grainger, 2017). This is evidence for some early, form-based syntactic processing. These processes are reflected in EEG recordings; Wen, Snell & Grainger (2019) found greater negative amplitude for scrambled stimuli compared to grammatical stimuli ~300ms . We build upon this work, asking: what kinds of syntactic features is this brain response sensitive to? [METHODS] N = 12 English speakers participated in two adaptations of the Snell & Grainger (2017) paradigm, in which short sentences were displayed briefly, followed by a memory probe. In the first task, stimuli were 48 sets of 5-word, grammatical sentences, ungrammatical sentences with a subject-verb number agreement error, ungrammatical scrambled sentences, and consonant strings matched in length to the sentential stimuli. In the second task, stimuli were 64 sets of 5-word sentences. We manipulated whether the subject was a wh-expression (±WH-Subject), and whether the object was a wh-expression (±WH-Object). EEG signals were recorded with a 64-channel BrainVision actiCHamp+ system, with FCz as on-line reference. [RESULTS] For both tasks, sensor space spatio-temporal cluster-based permutation tests were conducted in 'N400' (200–500ms) and 'P600' (500–800ms) time windows, plus an additional exploratory analysis in the entire time window (0–800ms). For the first task, we identified a cluster 380–693 ms, showing a difference among the 4 conditions over left lateral sensors (p < 0.01). Qualitatively, the consonant string waveform diverges negatively from the waveforms of the linguistic conditions. Subsequent pairwise spatio-temporal cluster-based permutation tests between grammatical stimuli and the three other conditions identified an effect of consonant strings, 200–500ms, distributed over posterior midline sensors (p < 0.01). For the second task, we identified a cluster 258–335ms, showing greater positivity for NP subjects over WH subjects, irrespective of the form of the object, over left lateral and left posterior sensors (p < 0.03). [CONCLUSION] While grammatical vs ungrammatical EEG differences do not yet emerge in the first task---even though they would be expected---the results of the first task do suggest that linguistically plausible stimuli are processed differently from linguistically content-less consonant strings. With respect to the second task, interrogatives with NP subjects require 'do'-insertion, regardless of the object's form– 'Did she pet this dog?', 'Which dog did she pet?' vs 'Who pet this dog?', 'Who pet which dog?. Thus, the early divergence in EEG signals may reflect sensitivity to this superficial cue to syntactic structure. When data collection is complete, we will use the digitized sensor positions coregistered with the freesurfer average ('fsaverage') template brain to compute the inverse solution using the sLORETA method to identify the source space correlates of any significant sensor-space clusters.
Topic Areas: Reading, Syntax and Combinatorial Semantics