Parafoveally perceived orthographic cues facilitate foveal semantic processing: Evidence from event-related potentials

Abstract

Readers extract information from words viewed parafoveally, but it is unclear whether this processing is limited to orthography or if it extends to lexico-semantic content. In the current ERP study, we measured the N400 responses to words that were perceived parafoveally and/or foveally using the RSVP-with-flankers paradigm and a parafoveal masking manipulation. We compared anomalous orthographically related (neighbor) and unrelated (non-neighbor) words to expected words to determine whether the N400 responses were driven by orthographic and/or semantic processing. We observed a large parafoveal N400 effect in response to the non-neighbors (versus expected), and a smaller, later parafoveal N400 for neighbors, suggesting that the parafoveal response is largely orthographic in nature. We also observed a significant reduction in foveal N400 magnitude when non-neighbor words were previously visible parafoveally (but not for the foveal N400 response to neighbors), suggesting that facilitation of foveal processing is driven by parafoveal detection of orthographic violations.