This study investigates brain responses to violations of information structure in wh-question-answer pairs, with particular emphasis on violations of focus assignment in it-clefts (It was the queen that silenced the banker). Two types of ERP responses in answers to wh-questions were found. First, all words in the focus-marking (cleft) position elicited a large positivity (P3b) characteristic of sentence-final constituents, as did the final words of these sentences, which suggests that focused elements may trigger integration effects like those seen at sentence end. Second, the focusing of an inappropriate referent elicited a smaller, N400-like effect. The results show that comprehenders actively use structural focus cues and discourse-level restrictions during online sentence processing. These results, based on visual stimuli, were different from the brain response to auditory focus violations indicated by pitch-accent [Hruska, C., Steinhauer, K., Alter, K., & Steube, A. (2000). ERP effects of sentence accents and violations of the information structure. In Poster presented at the 13th annual CUNY conference on human sentence processing, San Diego, CA.], but similar to brain responses to newly introduced discourse referents [Bornkessel, I., Schlesewsky, M., & Friederici, A. (2003). Contextual information modulated initial processes of syntactic integration: the role of inter- versus intrasentential predictions. Journal of Experimental Psychology: Learning, Memory and Cognition, 29, 871-882.].