Mixed Responses: Why Readers Spend Less Time at Unfavorable Landing Positions

Abstract

This paper investigates why the average fixation duration tends to decrease from the center to the two ends of a word. Specifically, it examines (a) whether unfavorable landing positions trigger a corrective mechanism, (b) whether the triggering is based on the internal efference copy mechanism, and (c) whether the corrective mechanism is specific to fixations that missed their targeted words. To estimate the mean and proportion of the corrective fixations, a 3-parameter mixture model was fitted to distributions of first fixation duration from two large eye movement databases in studies 1 and 2. Study 3 experimentally created mislocated fixations using a gaze-contingent screen shift paradigm. There is little evidence for the efference copy mechanism and limited support for the mislocated fixations hypothesis. Overall, data suggest a process that terminates fixations sooner than would during normal reading; it is triggered by the visual input during a fixation, and is flexibly engaged at eccentric landing positions and in reading short words. Implications to theories of reading eye movements are discussed.