ERP correlates of intramodal and crossmodal L2 acquisition

BACKGROUND: The present study compared the neural correlates of an intramodally and a crossmodally acquired second language (L2). Deaf people who had learned their L1, German Sign Language (DGS), and their L2, German, through the visual modality were compared with hearing L2 learners of German and German native speakers. Correct and incorrect German sentences were presented word by word on a computer screen while the electroencephalogram was recorded. At the end of each sentence, the participants judged whether or not the sentence was correct. Two types of violations were realized: Either a semantically implausible noun or a violation of subject-verb number agreement was embedded at a sentence medial position. RESULTS: Semantic errors elicited an N400, followed by a late positivity in all groups. In native speakers of German, verb-agreement violations were followed by a left lateralized negativity, which has been associated with an automatic parsing process. We observed a syntax related negativity in both high performing hearing and deaf L2 learners as well. Finally, this negativity was followed by a posteriorly distributed positivity in all three groups. CONCLUSIONS: Although deaf learners have learned German as an L2 mainly via the visual modality they seem to engage comparable processing mechanisms as hearing L2 learners. Thus, the data underscore the modality transcendence of language.