Concerning the automaticity of syntactic processing

Ln a within-subjects design, event-related potentials were compared for two types of sentence-final syntactic errors: Incorrect verb inflection and in correct word category (phrase structure). In a grammatical judgment task, t hese errors triggered robust N400 and P600 components. To assess the degree of automaticity of the underlying linguistic processes, the N400 and P600 effects were measured in a task for which the participants judged whether a word in a sentence was printed in upper case. In this physical judgment ta sk, the N400 and P600 following verb inflection errors were greatly attenua ted or absent, whereas those elicited by word category violation were only slightly diminished in amplitude. The data suggest that word category infor mation is processed more automatically than inflectional information, The P 600 appears to reflect a relatively controlled language-related process.