Sign languages contain the same structural properties as spoken languages (e.g. phonologic, syntactic and semantic elements). The present study investigated, to which extend visual-manual languages activate similar neural systems for both syntactic and semantic processes. Event-related potentials (ERPs) are known to show different patterns after semantic and syntactic violations in spoken languages. We investigated semantic and syntactic aspects of German Sign Language (DGS) with the ERPs.
Congenitally deaf native signers of DGS watched movies of naturally signed sentences. Semantic violations (implausible nouns) and syntactic violations (verb-agreement violations) were embedded. Verb-agreement violations elicited a posterior negativity and a P600 whereas semantic violations are followed by a N400. The same participants were investigated with German written sentences with either a semantic (implausible noun) or a syntactic violation (number agreement violation at the verb). After syntactic violations a P600 was observed and semantic violations were followed by a N400.
Thus, native signers of DGS display distinct ERP patterns for semantic and syntactic processing, comparable to those observed for spoken German. Moreover, the result pattern for their second language (German) is similar to that of hearing second language learners.