The Information Gathering Framework - a Cognitive Model of Regressive Eye Movements during Reading

In this article we present a new eye movement control framework that describes the interaction between fixation durations and regressive saccades during reading: The Information Gathering Framework (IGF). Based on the FC model proposed by Bicknell and Levy [15], the basic idea of the IGF is that a confidence level for each word is computed while being monitored by three independent thresholds. These thresholds shape eye movement behavior by increasing fixation duration, triggering a regression, or guiding regression target selection. In this way, the IGF does not only account for regressive eye movements but also provides a framework able to model eye movement control during reading across different scenarios. Importantly, within the IGF it is assumed that two different types of regressive eye movements exist which differ with regard to their releases (integrations difficulties vs. missing evidence) but also with regard to their time course. We tested the predictions of the IGF by re-analyzing an experiment of Weiss et al. [57] and found, inter alia, clear evidence for shorter fixation durations before regressive saccades relative to progressive saccades, with the exception of the last region. This clearly supports the assumptions of the IGF. In addition, we found evidence that there exists a window of about 15-20 characters to the left of the current fixation that plays an important role in target selection, probably indicating the perceptual span during a regressive saccade.