Beyond doze probability: Parafoveal processing of semantic and syntactic information during reading

Theories of eye movement control in reading assume that early oculomotor decisions are determined by a word's frequency and doze probability. This assumption is challenged by evidence that readers are sensitive to the contextual plausibility of an upcoming word: First-pass fixation probability and duration are reduced when the parafoveal preview is a plausible, but unpredictable, word relative to an implausible word. The present study sought to establish whether the source of this effect is sensitivity to violations of syntactic acceptability. In two experiments, the gaze-contingent boundary paradigm was used to compare contextually plausible previews to semantically acceptable and anomalous previews that either matched or violated syntactic rules. Results showed that readers benefited from the convergence of semantic and syntactic acceptability early enough in the timecourse of reading to affect skipping. In addition, both semantic and syntactic plausibility yielded preview effects on target fixation duration measures, providing direct evidence of parafoveal syntactic processing in reading. These results highlight the limitations of relying solely on doze probability to index contextual influences on early lexical processing. The implications of the data for models of eye movement control and language comprehension are discussed. (C) 2017 Elsevier Inc. All rights reserved.