Quantifying individual differences in native and nonnative sentence processing

Abstract Research in sentence processing has increasingly examined the role of individual differences in language comprehension. In work on native and nonnative sentence processing, examining individual differences can contribute crucial insight into theoretical debates about the extent to which nativelike processing is possible in a nonnative language. Despite this increased interest in individual differences, whether commonly used psycholinguistic tasks can reliably measure individual differences between participants has not been systematically examined. As a preliminary examination of this issue in nonnative processing, we report a self-paced reading experiment on garden-path sentences in native and nonnative comprehension. At the group level we replicated previously observed findings in native and nonnative speakers. However, while we found that our self-paced reading experiment was a reliable way of assessing individual differences in overall reading speed and comprehension accuracy, it did not consistently measure individual differences in the size of garden-path effects in our sample ( N = 64 native and 64 nonnative participants, and 24 experimental items). These results suggest that before individual differences in sentence processing can be meaningfully assessed, the question of whether commonly used tasks can consistently measure individual differences requires systematic examination.