Research report ERP effects of the processing of syntactic long-distance dependencies Colin Phillips a,b, * , Nina Kazanina a , Shani H. Abada c a Department of Linguistics, University of Maryland, 1401 Marie Mount Hall, College Park, MD 20742, United States b Neuroscience and Cognitive Science Program, University of Maryland, United States c School of Communication Sciences and Disorders, McGill University, Canada Accepted 30 September 2004 Available online 19 November 2004 Abstract In behavioral studies on sentence comprehension, much evidence indicates that shorter dependencies are preferred over longer dependencies, and that longer dependencies incur a greater processing cost. However, it remains uncertain which of the various steps involved in the processing of long-distance dependencies is responsible for the increased cost of longer dependencies. Previous sentence comprehension studies using event-related potentials (ERPs) have revealed response components that reflect the construction [J. King, M. Kutas, Who did what and when? Using word- and clause-level ERPs to monitor working memory usage in reading. Journal of Cognitive Neuroscience, 7, (1995) 376–395.] and completion [E. Kaan, A. Harris, E. Gibson, P. Holcomb, The P600 as an index of syntactic integration difficulty. Language and Cognitive Processes, 5, (2000) 159–201.] of long-distance wh-dependencies. This article reports one off-line rating study and one ERP study that manipulated both the presence of wh-dependencies and the length of the dependencies (one clause vs. two clauses), with the aim of clarifying the locus of length-sensitivity and the functional role of associated ERP components. Results of the off- line study confirm that longer wh-dependencies incur greater processing cost. Results of the ERP study indicate that both a sustained anterior negativity that follows the initiation of the wh-dependency and also a late posterior positivity (P600) that marks the completion of the dependency are sensitive to the presence of a wh-dependency, but do not show amplitude variations reflecting the length of the dependency. However, the P600 is delayed when it marks the completion of a longer wh-dependency. This suggests that both the sustained negativity and the P600 reflect length-insensitive aspects of the construction of syntactic dependencies. In addition, an N400 component is elicited in the middle of the two clause wh- dependency, upon encountering a verb with an argument structure that prevents completion of the dependency. D 2004 Elsevier B.V. All rights reserved. Theme: Neural basis of behavior Topic: Cognition Keywords: Event-related potentials; Sentence processing; Wh-questions; Long-distance dependencies; P600; Sustained negativity; N400 1. Introduction 1.1. Filler-gap dependencies A key property of natural language is its ability to build vast numbers of different expressions from a relatively small store of memorized words. This is made possible by the ability to combine words into hierarchically organized sentence structures. A hallmark of hierarchical sentence structure is the existence of long-distance dependencies between words and phrases that are not adjacent in the surface sequence of words. Long-distance dependencies can arise in at least two ways. They can arise in situations where elements are structurally close to one another and in their canonical positions, but are separated by additional material, as in subject–verb agreement relations such as dThe man who always delivers the newspaper drives a big black truck T. Long-distance dependencies also arise in situations where a phrase is displaced from its canonical position in 0926-6410/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.cogbrainres.2004.09.012 * Corresponding author. Department of Linguistics, University of Maryland, 1401 Marie Mount Hall, College Park, MD 20742, United States. Fax: +1 301 405 7104. E-mail address: colin@umd.edu (C. Phillips). Cognitive Brain Research 22 (2005) 407 – 428 www.elsevier.com/locate/cogbrainres