Electrophysiological responses to syntactic and 'morphological' structures: evidence from Mandarin Chinese

What are syntactic relations, and how does our brain infer them from a string of text characters? In the EEG study reported here we aimed to investigate these questions by contrasting syntactically separable compounds (zao4...fan3 -> 'rebel') and non-separable compounds (chi2yi2 -> 'hesitate') in Mandarin Chinese. Because both kinds of compounds have non-compositional meanings, their syntactic differences provide an elegant means for dissociating syntactic from semantic relations. Because non-separable compounds fit the traditional criteria for 'wordhood', this contrast also provides a means for asking whether syntactic and morphological relations are inferred in qualitatively different ways. We found that, relative to non-separable compounds, syntactically separable compounds elicited a left anterior negativity (LAN) effect between 275-400ms. Even though readers were always presented with the compounds in their unseparated form, our results suggest that the potentially separable compound forms drive the inference of a more complex set of underlying syntactic relations. In a companion manipulation in the same participants, we observed a qualitatively similar LAN effect when comparing non-separable compound nouns with simplex nouns. This finding raises doubts for the existence of a clear-cut distinction between 'syntax' and 'morphology', at least in processing. ### Competing Interest Statement The authors have declared no competing interest.