Context-modulating effect on processing scientific metaphors: Evidence from ERPs

Previous event-related potential (ERP) studies have demonstrated the neural specificity of cognitive processing mechanisms in scientific metaphors. This property makes semantic retrieval and extraction more difficult compared to conventional metaphors. However, the role of context in modulating the comprehension of scientific metaphors remains unclear, and there has been no analysis or categorization of abstract and difficult scientific metaphors. In this study, we used the sentence-final word paradigm to investigate the effects of different contextual conditions on the comprehension of two types of scientific metaphors. We aimed to observe (Experiment 1) whether there are any differences between the processing of the two types of scientific metaphors in the context-free condition and (Experiment 2) whether the context affects the comprehension of the two types of scientific metaphors in the contextualized condition. Additionally, we explored the modulating effects of relevant and irrelevant contexts on the two types of scientific metaphors. Both N400 and late negative component (LN) effects were found in the two experiments. The N400 analysis showed that SMF (SMF refers to scientific metaphors whose source domain and target domain have similarities in functions in present study.) evoked more negative N400 than SMS (SMS refers to scientific metaphors whose source domain and target domain have similarities in shapes in present study) in the context-free condition. The result suggests that the processing of SMF might be more difficult than that of SMS. However, in the relevant-context condition, there was no significant difference in the N400 amplitudes of the two types of scientific metaphors. In contrast, in the irrelevant-context condition, SMS elicited significantly more negative N400 than SMF. Analysis of the LN revealed no significant differences between SMS and SMF in the two experiments. The results indicate that the context might affect information extraction and retrieval, but not the late reasoning stage about scientific knowledge. Moreover, the relevant context might facilitate the comprehension of both types of scientific metaphors, whereas the irrelevant context might hinder the processing of them. More importantly, the interference seems greater for SMS.