The role of working memory in interference resolution during Chinese sentence comprehension: Evidence from event-related potentials (ERPs)
Martin, Randi C.
Doctor of Philosophy
Interference during sentence comprehension occurs when readers use semantic and syntactic cues to retrieve earlier sentence information to integrate with later information and intervening material partially matches these cues, resulting in more parsing difficulty. This thesis collected event-related brain potentials (ERPs) while participants processed Chinese sentences with semantic and syntactic interference to address two main questions: 1) When do semantic and syntactic interference effects occur and do they interact with each other? 2) What is the role of working memory (WM) mechanisms in interference resolution? Semantic and syntactic interference were examined during processing of the critical main clause verb (e.g., “complain”) that required the retrieval of a human subject noun. The degree of semantic interference was manipulated through varying the semantic plausibility of a distracting noun (e.g., human vs. non-human), and syntactic interference was manipulated through varying the distracting noun’s grammatical role in the relative clause (i.e., subject vs. object). Individual differences measures were collected on aspects of working memory, executive function, and verbal knowledge. Regarding the timing of interference effects, the ERP results at the critical verb showed negative anterior effects between 300 – 500 ms for both syntactic and semantic interference. Syntactic interference also induced a P600 effect and semantic interference also induced a late left anterior negativity. I interpret the early anterior negativities as reflecting a first stage process of detecting the semantic or syntactic interference, and the late ERPs as reflecting a second stage of reanalysis/revision during sentence processing. Importantly, the current results demonstrated that semantic processing plays an immediate and important role in Chinese, because the semantic interference effect was observed as early as the syntactic interference effect even when the distracting noun’s syntactic features strongly eliminated it from the distractor set. In contrast, semantic interference has been shown to be delayed and even blocked in previous English studies using similar materials. Regarding the role of WM in interference resolution, the present study supports a role of attentional control underlying sentence comprehension. Subjects with better resistance to proactive interference, as measured by a recent negatives task, had less difficulty in syntactic interference resolution, as indexed by a reduced mean amplitude of the P600 effect elicited by the high syntactic interference condition, even after controlling for their verbal knowledge and general processing speed. This result is consistent with the argument that attentional control helps subjects to recover from interference during later controlled aspects of sentence processing.
Retrieval interference; Working memory capacity; Cue-based retrieval; Chinese sentence comprehension; Event-related potentials (ERPs)