Electrophysiological evidence for dissimilarities in the processing of gender and number agreement in Spanish l2 bilinguals
It has been observed that Spanish L2 speakers produce mistakes for gender more frequently than for number agreement. This asymmetry has also been observed in their processing of the same features. This study’s purpose was to determine whether there are recognizable electrophysiological differences in the processing of these agreement features and to explore possible neurocognitive underpinnings for such differences in bilingual speakers. In order to investigate this, the study used ERP method to observe the responses of Spanish L2 bilinguals to gender and number agreement violations between quantifiers and nouns in Spanish. The canonical ERP observed for both grammatical gender and number agreement violations in Spanish monolinguals is a biphasic LAN-P600 effect. This has also been found in some studies examining bilinguals, though a P600 effect alone is the most common result. In the present study, gender violations elicited a broad distributed early anterior negativity (eLAN) at the 100-200 ms window, a left-central anterior negativity (LAN) in the 250-400ms, and no P600 effect. Number violations, on the other hand, showed the broadly distributed anterior negativity (eLAN), and both LAN and P600 effects. The results confirm differences in the processing of the features. Moreover, the data show that gender demonstrates less saliency to English speakers than does number, whose violations showed a native-like processing pattern. These results support bilingualism models that propose that features that are not equal between L1 and L2 can be developed by learners who started learning their second language after childhood. From a linguistic perspective, the results for gender show a cue-based first check process (eLAN) and cue-based morphosyntactic processing (LAN), without the lexical access to check and repair processes, as evidenced by the lack of P600. This supports the model of a dual-route for gender agreement. The cue-based route (proposed for morphological features) seems to be used by bilinguals in this study, even though grammatical gender is a lexical feature. Possible explanations include a lack of sufficient cognitive resources to continue to the repair stage, or possibly an inability to do so caused by the incomplete stage in the development of the feature in the participants.