@article{NuthmannSmithEngbertetal.2010,
  author    = {Nuthmann, Antje and Smith, Tim J. and Engbert, Ralf and Henderson, John M.},
  title     = {CRISP: a computational model of fixation duration in scene viewing},
  year      = {2010},
  abstract  = {Eye-movement control during scene viewing can be represented as a series of individual decisions about where and when to move the eyes. While substantial behavioral and computational research has been devoted to investigating the placement of fixations in scenes, relatively little is known about the mechanisms that control fixation durations. Here, we propose a computational model (CRISP) that accounts for saccade timing and programming and thus for variations in fixation durations in scene viewing. First, timing signals are modeled as continuous-time random walks. Second, difficulties at the level of visual and cognitive processing can inhibit and thus modulate saccade timing. Inhibition generates moment-by-moment changes in the random walk's transition rate and processing-related saccade cancellation. Third, saccade programming is completed in 2 stages: an initial, labile stage that is subject to cancellation and a subsequent, nonlabile stage. Several simulation studies tested the model's adequacy and generality. An initial simulation study explored the role of cognitive factors in scene viewing by examining how fixation durations differed under different viewing task instructions. Additional simulations investigated the degree to which fixation durations were under direct moment-to-moment control of the current visual scene. The present work further supports the conclusion that fixation durations, to a certain degree, reflect perceptual and cognitive activity in scene viewing. Computational model simulations contribute to an understanding of the underlying processes of gaze control.},
  language  = {en}
}
@article{SchadNuthmannEngbert2010,
  author    = {Schad, Daniel and Nuthmann, Antje and Engbert, Ralf},
  title     = {Eye movements during reading of randomly shuffled texts},
  issn      = {0042-6989},
  year      = {2010},
  abstract  = {In research on eye-movement control during reading, the importance of cognitive processes related to language comprehension relative to visuomotor aspects of saccade generation is the topic of an ongoing debate. Here we investigate various eye-movement measures during reading of randomly shuffled meaningless text as compared to normal meaningful text. To ensure processing of the material, readers were occasionally probed for words occurring in normal or shuffled text. For reading of shuffled text we observed longer fixation times, less word skippings, and more refixations than in normal reading. Shuffled-text reading further differed from normal reading in that low-frequency words were not overall fixated longer than high-frequency words. However, the frequency effect was present on long words, but was reversed for short words. Also, consistent with our prior research we found distinct experimental effects of spatially distributed processing over several words at a time, indicating how lexical word processing affected eye movements. Based on analyses of statistical linear mixed-effect models we argue that the results are compatible with the hypothesis that the perceptual span is more strongly modulated by foveal load in the shuffled reading task than in normal reading. Results are discussed in the context of computational models of reading.},
  language  = {en}
}
@article{YanKlieglRichteretal.2010,
  author    = {Yan, Ming and Kliegl, Reinhold and Richter, Eike M. and Nuthmann, Antje and Shu, Hua},
  title     = {Flexible saccade-target selection in Chinese reading},
  issn      = {1747-0218},
  doi       = {10.1080/17470210903114858},
  year      = {2010},
  abstract  = {As Chinese is written without orthographical word boundaries (i.e., spaces), it is unclear whether saccade targets are selected on the basis of characters or words and whether saccades are aimed at the beginning or the centre of words. Here, we report an experiment where 30 Chinese readers read 150 sentences while their eye movements were monitored. They exhibited a strong tendency to fixate at the word centre in single-fixation cases and at the word beginning in multiple-fixation cases. Different from spaced alphabetic script, initial fixations falling at the end of words were no more likely to be followed by a refixation than initial fixations at word centre. Further, single fixations were shorter than first fixations in two-fixation cases, which is opposite to what is found in Roman script. We propose that Chinese readers dynamically select the beginning or centre of words as saccade targets depending on failure or success with segmentation of parafoveal word boundaries.},
  language  = {en}
}