Sensitivity to Inflectional Morphology in a Non-native Language: Evidence From ERPs

Abstract

The extent to which non-native speakers are sensitive to morphological structure during language processing remains a matter of debate. The present study used a masked-priming lexical decision task with simultaneous electroencephalographic (EEG) recording to investigate whether native and non-native speakers of French yield similar or different behavioral and brain-level responses to inflected verbs. The results from reaction time and EEG analyses indicate that both native and non-native French speakers were indeed sensitive to morphological structure, and that this sensitivity cannot be explained simply by the presence of orthographic or semantic overlap between prime and target. Moreover, sensitivity to morphological structure in non-native speakers was not influenced by proficiency (as reflected by the N400); lower-level learners show similar sensitivity at the word level as very advanced learners. These results demonstrate that native-like processing of inflectional morphology is possible in adult learners, even at lower levels of proficiency, which runs counter to proposals suggesting that native-like processing of inflection is beyond non-native speakers' reach.

The question of whether or not adult learners of a second language can decompose inflected words (e.g., walked) into morphological constituents (walk+-ed) and access morphological-level representations in the lexicon has received much attention in recent years. Some researchers propose that, like native speakers, second language (L2) learners are indeed sensitive to the morphological structure of inflected forms, and process complex forms via their morphological constituents (e.g., Basnight-Brown et al., 2007; Feldman et al., 2010; Coughlin and Tremblay, 2015), although it has been suggested that this may only be possible at high levels of proficiency (e.g., Ullman, 2005; Bowden et al., 2010; Babcock et al., 2012). By contrast, other researchers have proposed that adult L2 learners are insensitive to inflectional morphological structure due to a deficient grammar, and this deficiency is not predicted to improve with increased proficiency (e.g., Silva and Clahsen, 2008; Neubauer and Clahsen, 2009; Clahsen et al., 2010; Jacob et al., 2013, 2018). While some studies have found evidence of non-native speakers decomposing derived words (e.g., Silva and Clahsen, 2008; Jacob et al., 2018), many studies fail to find evidence for inflectional morphology decomposition. Given mixed results from recent studies, our current understanding of how non-native speakers process morphologically complex words remains unclear. The present study used a masked-priming lexical decision task during EEG recording to investigate how native and non-native French speakers process verbal inflection morphology. The combined use of masked priming and EEG allows one to test not only whether learners are able to show native-like sensitivity to inflectional morphology in their behavioral responses, but also whether their brain responses are indeed qualitatively similar to those of native speakers.