TY - JOUR A1 - Risse, Sarah A1 - Hohenstein, Sven A1 - Kliegl, Reinhold A1 - Engbert, Ralf T1 - A theoretical analysis of the perceptual span based on SWIFT simulations of the n+2 boundary paradigm JF - Visual cognition N2 - Eye-movement experiments suggest that the perceptual span during reading is larger than the fixated word, asymmetric around the fixation position, and shrinks in size contingent on the foveal processing load. We used the SWIFT model of eye-movement control during reading to test these hypotheses and their implications under the assumption of graded parallel processing of all words inside the perceptual span. Specifically, we simulated reading in the boundary paradigm and analysed the effects of denying the model to have valid preview of a parafoveal word n + 2 two words to the right of fixation. Optimizing the model parameters for the valid preview condition only, we obtained span parameters with remarkably realistic estimates conforming to the empirical findings on the size of the perceptual span. More importantly, the SWIFT model generated parafoveal processing up to word n + 2 without fitting the model to such preview effects. Our results suggest that asymmetry and dynamic modulation are plausible properties of the perceptual span in a parallel word-processing model such as SWIFT. Moreover, they seem to guide the flexible distribution of processing resources during reading between foveal and parafoveal words. KW - Eye movements KW - Reading KW - Computational modelling KW - Perceptual span KW - Preview Y1 - 2014 U6 - https://doi.org/10.1080/13506285.2014.881444 SN - 1350-6285 SN - 1464-0716 VL - 22 IS - 3-4 SP - 283 EP - 308 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Krügel, Andre A1 - Vitu, Francoise A1 - Engbert, Ralf T1 - Fixation positions after skipping saccades - a single space makes a large difference JF - Attention, perception, & psychophysics : AP&P ; a journal of the Psychonomic Society, Inc. N2 - During reading, saccadic eye movements are generated to shift words into the center of the visual field for lexical processing. Recently, Krugel and Engbert (Vision Research 50:1532-1539, 2010) demonstrated that within-word fixation positions are largely shifted to the left after skipped words. However, explanations of the origin of this effect cannot be drawn from normal reading data alone. Here we show that the large effect of skipped words on the distribution of within-word fixation positions is primarily based on rather subtle differences in the low-level visual information acquired before saccades. Using arrangements of "x" letter strings, we reproduced the effect of skipped character strings in a highly controlled single-saccade task. Our results demonstrate that the effect of skipped words in reading is the signature of a general visuomotor phenomenon. Moreover, our findings extend beyond the scope of the widely accepted range-error model, which posits that within-word fixation positions in reading depend solely on the distances of target words. We expect that our results will provide critical boundary conditions for the development of visuomotor models of saccade planning during reading. KW - Eye movements KW - Reading KW - Motor control KW - Skipping Y1 - 2012 U6 - https://doi.org/10.3758/s13414-012-0365-1 SN - 1943-3921 VL - 74 IS - 8 SP - 1556 EP - 1561 PB - Springer CY - New York ER - TY - JOUR A1 - Schad, Daniel A1 - Nuthmann, Antje A1 - Engbert, Ralf T1 - Your mind wanders weakly, your mind wanders deeply - objective measures reveal mindless reading at different levels JF - Cognition : international journal of cognitive science N2 - When the mind wanders, attention turns away from the external environment and cognitive processing is decoupled from perceptual information. Mind wandering is usually treated as a dichotomy (dichotomy-hypothesis), and is often measured using self-reports. Here, we propose the levels of inattention hypothesis, which postulates attentional decoupling to graded degrees at different hierarchical levels of cognitive processing. To measure graded levels of attentional decoupling during reading we introduce the sustained attention to stimulus task (SAST), which is based on psychophysics of error detection. Under experimental conditions likely to induce mind wandering, we found that subjects were less likely to notice errors that required high-level processing for their detection as opposed to errors that only required low-level processing. Eye tracking revealed that before errors were overlooked influences of high- and low-level linguistic variables on eye fixations were reduced in a graded fashion, indicating episodes of mindless reading at weak and deep levels. Individual fixation durations predicted overlooking of lexical errors 5 s before they occurred. Our findings support the levels of inattention hypothesis and suggest that different levels of mindless reading can be measured behaviorally in the SAST. Using eye tracking to detect mind wandering online represents a promising approach for the development of new techniques to study mind wandering and to ameliorate its negative consequences. KW - Mind wandering KW - Reading KW - Eye movements KW - Signal detection theory KW - Levels of processing KW - Sustained attention Y1 - 2012 U6 - https://doi.org/10.1016/j.cognition.2012.07.004 SN - 0010-0277 VL - 125 IS - 2 SP - 179 EP - 194 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schad, Daniel A1 - Engbert, Ralf T1 - The zoom lens of attention simulating shuffled versus normal text reading using the SWIFT model JF - Visual cognition N2 - Assumptions on the allocation of attention during reading are crucial for theoretical models of eye guidance. The zoom lens model of attention postulates that attentional deployment can vary from a sharp focus to a broad window. The model is closely related to the foveal load hypothesis, i.e., the assumption that the perceptual span is modulated by the difficulty of the fixated word. However, these important theoretical concepts for cognitive research have not been tested quantitatively in eye movement models. Here we show that the zoom lens model, implemented in the SWIFT model of saccade generation, captures many important patterns of eye movements. We compared the model's performance to experimental data from normal and shuffled text reading. Our results demonstrate that the zoom lens of attention might be an important concept for eye movement control in reading. KW - Computational modelling KW - Eye movements KW - Foveal load hypothesis KW - Perceptual span KW - Reading KW - Zoom lens model of attention Y1 - 2012 U6 - https://doi.org/10.1080/13506285.2012.670143 SN - 1350-6285 SN - 1464-0716 VL - 20 IS - 4-5 SP - 391 EP - 421 PB - Wiley CY - Hove ER - TY - JOUR A1 - Engelmann, Felix A1 - Vasishth, Shravan A1 - Engbert, Ralf A1 - Kliegl, Reinhold T1 - A framework for modeling the interaction of syntactic processing and eye movement control JF - Topics in cognitive science N2 - We explore the interaction between oculomotor control and language comprehension on the sentence level using two well-tested computational accounts of parsing difficulty. Previous work (Boston, Hale, Vasishth, & Kliegl, 2011) has shown that surprisal (Hale, 2001; Levy, 2008) and cue-based memory retrieval (Lewis & Vasishth, 2005) are significant and complementary predictors of reading time in an eyetracking corpus. It remains an open question how the sentence processor interacts with oculomotor control. Using a simple linking hypothesis proposed in Reichle, Warren, and McConnell (2009), we integrated both measures with the eye movement model EMMA (Salvucci, 2001) inside the cognitive architecture ACT-R (Anderson et al., 2004). We built a reading model that could initiate short Time Out regressions (Mitchell, Shen, Green, & Hodgson, 2008) that compensate for slow postlexical processing. This simple interaction enabled the model to predict the re-reading of words based on parsing difficulty. The model was evaluated in different configurations on the prediction of frequency effects on the Potsdam Sentence Corpus. The extension of EMMA with postlexical processing improved its predictions and reproduced re-reading rates and durations with a reasonable fit to the data. This demonstration, based on simple and independently motivated assumptions, serves as a foundational step toward a precise investigation of the interaction between high-level language processing and eye movement control. KW - Sentence comprehension KW - Eye movements KW - Reading KW - Parsing difficulty KW - Working memory KW - Surprisal KW - Computational modeling Y1 - 2013 U6 - https://doi.org/10.1111/tops.12026 SN - 1756-8757 VL - 5 IS - 3 SP - 452 EP - 474 PB - Wiley-Blackwell CY - Hoboken ER -