Negative valence effects on the processing of agreement dependencies are mediated by ERP individual differences in morphosyntactic processing

Some previous ERP studies on the interaction between emotion and morphosyntactic processing have shown emotional modulations in a left anterior negativity (LAN) indexing the early detection of agreement mismatches, whereas others have failed to report such differences. Here we examined individual differences in the morphosyntactic processing of emotional words, which might account for the divergences found in previous studies. To this aim, neutral and negative adjectives in grammatically correct and incorrect noun phrases (NPs) were presented to 62 participants. The general analyses showed an emotionality effect in the N100 component as well as enhanced LAN and P600 amplitudes in mismatch trials. Further analyses confirmed that most participants showed either LAN (negativity dominance) or P600 (positivity dominance) effects. Importantly, these two groups exhibited different patterns over the time course. Overall, our data suggest that individual differences should be considered when investigating the interplay between emotion and morphosyntactic processing.