Do effects of visual contrast and font difficulty on readers' eye movements interact with effects of word frequency or predictability?

The time a reader's eyes spend on a word is influenced by visual (e.g., contrast) as well as lexical (e.g., word frequency) and contextual (e.g., predictability) factors. Well-known visual word recognition models predict that visual and higher-level manipulations may have interactive effects on early eye movement measures, because of cascaded processing between levels. Previous eye movement studies provide conflicting evidence as to whether they do, possibly because of inconsistent manipulations or limited statistical power. In the present study, 2 highly powered experiments used sentences in which a target word's frequency and predictability were factorially manipulated. Experiment 1 also manipulated visual contrast, and Experiment 2 also manipulated font difficulty. Robust main effects of all manipulations were evident in both experiments. In Experiment 1, interactions between the effect of contrast and the effects of frequency and predictability were numerically small and statistically unreliable in both early (word skipping, first fixation duration) and later (gaze duration, go-past time) measures. In Experiment 2, frequency and predictability did demonstrate convincing interactions with font difficulty, but only in the later measures, possibly implicating a checking mechanism. We conclude that although the predicted interactions in early eye movement measures may exist, they are sufficiently weak that they are difficult to detect even in large eye movement experiments. (PsycInfo Database Record (c) 2020 APA, all rights reserved).