PROCESSING RELATIVE CLAUSES VARYING ON SYNTACTIC AND SEMANTIC DIMENSIONS - AN ANALYSIS WITH EVENT-RELATED POTENTIALS

Event-related potentials were used to study how parsing of German rela tive clauses is influenced by semantic information. Subjects read well -formed sentences containing either a subject or an object relative cl ause and answered questions concerning the thematic roles expressed in those sentences. Half of the sentences contained past participles tha t on grounds of semantic plausibility biased either a subject or an ob ject relative reading; the other half contained past participles that provided no semantic information favoring either reading. The past par ticiple elicited an N400 component, larger in amplitude for neutral th an for semantically biased verbs, but this occurred only in the case o f subject relative clauses. More specific effects were obtained only f or a subgroup of subjects, when these were grouped into fast and slow comprehenders on the basis of their question-answering reaction times. Fast comprehenders showed larger N400 amplitudes for neutral than for semantically biased past participles in general and larger N400s for the latter when there was a bias for an object relative reading as opp osed to a subject relative reading. Syntactic ambiguity resolution, in dicated by an auxiliary in sentence final position, was associated in this subgroup with a positive component (P345), larger in amplitude fo r auxiliaries indicating an object relative reading than for those ind icating a subject relative reading. The latter component was independe nt of semantically biasing information given by a preceding past parti ciple. Implications of these findings for models of language comprehen sion are considered.