Brain responses to case-marking violations in German preschool children.

The processing of case-marking and argument structures was investigated in children at the age of 3 years, 4 years and 6 months, and 6 years. Two event-related potential (ERP) experiments were conducted in a case-marked language, i.e. German, comparing the processing of (a) double-nominative violations with subject-initial structures and (b) double-accusative violations with object-initial structures. It is known that for both violation types, adults display a biphasic N400/P600 ERP response, reflecting thematic-semantic, and syntactic processes. For double-nominative violations, 3-year-old children already show an adult-like processing pattern revealing their abilities to repair the tested structure. For double-accusative violations, ERP results indicate developmental processing differences with even 6-year-old children not showing an adult pattern. This suggests a late development of the complete function of the accusative case.