CNL Lunch Talks

Colin Phillips & Nina Kazanina

ERPs and Syntactic Long-Distance Dependencies

Thursday October 9th 2003, 12:30 PM, 3416 Marie Mount Hall

Most sentence-level research using ERPs has focused on the processing of different types of syntactic violations or anomalies. Recently, a small number of studies have shown that ERP methods can be used to track the processing of normal, non-disrupted processes. In this talk we use ERP measures of normal processing to investigate a controversy in the behavioral sentence comprehension literature.

In behavioral studies on sentence comprehension, much evidence indicates that shorter syntactic dependencies are preferred over longer dependencies, and that longer dependencies incur a greater processing cost. However, it remains unclear 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 (King & Kutas, 1995) and completion (Kaan et al., 2000) of long-distance wh-dependencies. This study reports an 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 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.