Individual Differences in Sentence Processing

Language comprehension is a complex task that involves constructing an incremental interpretation of a rapid sequence of incoming words before they fade from immediate memory, and yet the task is typically carried out effi ciently and with little conscious effort. Given the complexity associated with extracting intended meaning from an incoming linguistic signal, it is perhaps not surprising that multiple cognitive and perceptual systems are simultaneously engaged during the process. One ramifi cation of the multifarious nature of online language comprehension is that individuals tend to vary greatly in terms of their processing skill. Indeed, considerable by-subject variability in performance on syntactic processing tasks has been observed in numerous studies over the past two decades (e.g., King and Just, 1991 ; MacDonald, Just, and Carpenter, 1992 ; Novick, Trueswell, and Thompson-Schill, 2005 ; Pearlmutter and MacDonald, 1995 ; Swets et al., 2007 ), and yet debate still exists in regard to both the sources and the nature of this documented variability. This chapter explores some potential sources of variability in online comprehension skill. First, we briefl y discuss the proposed role that verbal working memory plays during syntactic processing, followed by the exploration of an alternative hypothesis that reassesses the effects of verbal working memory in terms of individual differences in learning-based, experiential factors. Subsequently, we consider the degree to which variability in “cognitive control” has the potential to account for variability in syntactic processing tasks, and then we touch on, briefl y, the infl uence of variability of perceptual systems on processes related to language comprehension. The literature on individual differences in syntactic processing is vast, and it is not possible to cover all of it in the small number of pages allotted to this chapter. Instead, we hope that the information contained here will help guide those with burgeoning interests in the area of individual differences research toward some of the current topics and debates within the fi eld. Before discussing factors that may account for variability in online syntactic C H A P T E R 1 7