Parafoveal preview differentially modulates word frequency and contextual predictability effects during reading

Despite more than five decades of research into eye movements in reading, questions remain about the relationship between lower-level lexical and higher-level semantic factors. We explored the simultaneous effects of word frequency (lower, higher), contextual predictability (lower, higher), and parafoveal preview (valid, invalid) on the processing of target words embedded in short passages of text. Using a repeated-measures design, 80 participants read 240 two-line passages, each containing a four- or five-letter target word. Corpus-based word frequencies and Cloze predictabilities were used as continuous variables in Bayesian mixed-effect analyses of fixation time and skipping measures. Key findings included robust main effects of frequency, predictability, and preview validity, as well as two-way interactions between Frequency × Preview in gaze duration, and Predictability × Preview in gaze duration and skipping. Frequency effects on gaze duration were greater under invalid preview conditions, suggesting that higher-frequency words facilitate corrective processing when preview is misleading. Predictability effects on gaze duration and skipping were enhanced under valid preview, indicating that contextual facilitation depends on coherent parafoveal input. No interaction was observed between frequency and predictability nor a three-way interaction, supporting the view that lexical access and contextual integration operate via distinct mechanisms. These findings highlight the critical role of parafoveal information in shaping the expression of lexical and contextual influences during reading.