Eye-movement control during reading
Frequency, predictability, and length of words influence fixation durations and probabilities. We show that the effects of these variables do not only depend on the porperties of the fixated word but also on those of the two neighboring words. Thus, visual and lexical word recognition during reading is distributed across several fixations. In addition, durations and probabilities depend on oculomotor factors. The results are simulated with a fully implemented computational model of saccade generation during reading (SWIFT). Theoretically controversial assumuption of this model are (1) parallel processing of words in the perceptual span, (2) autonomous initiation of saccade programs, modulated with a delay by foveal lexical difficulty, and (3) selection of saccade targets on the basis of gradients of lexical activity.