Understanding the Visual Constraints on Lexical Processing: New Empirical and Simulation Results

Word identification is slower and less accurate outside central vision, but the precise relationship between retinal eccentricity and lexical processing is not well specified by models of either word identification or reading. In a seminal eye-movement study, Rayner and Morrison (1981) found that participants made remarkably accurate naming and lexical-decision responses to words displayed more than 3 degrees from the center of vision-even under conditions requiring fixed gaze. However, the validity of these findings is challenged by a range of methodological limitations. We report a series of gaze-contingent lexical-decision and naming experiments that replicate and extend Rayner and Morrison's study to provide a more accurate estimate of how visual constraints delimit lexical processing. Simulations were conducted using the E-Z Reader model (Reichle et al., 2012) to assess the implications for understanding eye-movement control during reading. Augmenting the model's assumptions about the impact of both eccentricity and visual crowding on the rate of lexical processing provided good fits to the observed data without impairing the model's ability to simulate benchmark eye-movement effects. The findings are discussed with a view toward the development of a complete model of reading.