TY - JOUR A1 - Kliegl, Reinhold A1 - Wei, Ping A1 - Dambacher, Michael A1 - Yan, Ming A1 - Zhou, Xiaolin T1 - Experimental effects and individual differences in linear mixed models estimating the relationship between spatial, object, and attraction effects in visual attention JF - Frontiers in psychology N2 - Linear mixed models (LMMs) provide a still underused methodological perspective on combining experimental and individual-differences research. Here we illustrate this approach with two-rectangle cueing in visual attention (Egly et al., 1994). We replicated previous experimental cue-validity effects relating to a spatial shift of attention within an object (spatial effect), to attention switch between objects (object effect), and to the attraction of attention toward the display centroid (attraction effect), also taking into account the design-inherent imbalance of valid and other trials. We simultaneously estimated variance/covariance components of subject-related random effects for these spatial, object, and attraction effects in addition to their mean reaction times (RTs). The spatial effect showed a strong positive correlation with mean RT and a strong negative correlation with the attraction effect. The analysis of individual differences suggests that slow subjects engage attention more strongly at the cued location than fast subjects. We compare this joint LMM analysis of experimental effects and associated subject-related variances and correlations with two frequently used alternative statistical procedures. KW - linear mixed model KW - individual differences KW - visual attention KW - spatial attention KW - object-based attention Y1 - 2011 U6 - https://doi.org/10.3389/fpsyg.2010.00238 SN - 1664-1078 VL - 2 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Shu, Hua A1 - Zhou, Wei A1 - Yan, Ming A1 - Kliegl, Reinhold T1 - Font size modulates saccade-target selection in Chinese reading JF - Attention, perception, & psychophysics : AP&P ; a journal of the Psychonomic Society, Inc. N2 - In alphabetic writing systems, saccade amplitude (a close correlate of reading speed) is independent of font size, presumably because an increase in the angular size of letters is compensated for by a decrease of visual acuity with eccentricity. We propose that this invariance may (also) be due to the presence of spaces between words, guiding the eyes across a large range of font sizes. Here, we test whether saccade amplitude is also invariant against manipulations of font size during reading Chinese, a character-based writing system without spaces as explicit word boundaries for saccade-target selection. In contrast to word-spaced alphabetic writing systems, saccade amplitude decreased significantly with increased font size, leading to an increase in the number of fixations at the beginning of words and in the number of refixations. These results are consistent with a model which assumes that word beginning (rather than word center) is the default saccade target if the length of the parafoveal word is not available. KW - Eye movement KW - Saccade KW - Chinese KW - Font size Y1 - 2011 U6 - https://doi.org/10.3758/s13414-010-0029-y SN - 1943-3921 VL - 73 IS - 2 SP - 482 EP - 490 PB - Springer CY - New York ER - TY - JOUR A1 - Kliegl, Reinhold A1 - Bates, Douglas T1 - International collaboration in psychology is on the rise JF - Scientometrics : an international journal for all quantitative aspects of the science of science, communication in science and science policy N2 - There has been a substantial increase in the percentage for publications with co-authors located in departments from different countries in 12 major journals of psychology. The results are evidence for a remarkable internationalization of psychological research, starting in the mid 1970s and increasing in rate at the beginning of the 1990s. This growth occurs against a constant number of articles with authors from the same country; it is not due to a concomitant increase in the number of co-authors per article. Thus, international collaboration in psychology is obviously on the rise. KW - International collaboration KW - Psychological publications KW - Linear mixed model KW - Historical trend Y1 - 2011 U6 - https://doi.org/10.1007/s11192-010-0299-0 SN - 0138-9130 VL - 87 IS - 1 SP - 149 EP - 158 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Risse, Sarah A1 - Kliegl, Reinhold T1 - Adult age differences in the perceptual span during reading JF - Psychology and aging N2 - Following up on research suggesting an age-related reduction in the rightward extent of the perceptual span during reading (Rayner, Castelhano, & Yang, 2009), we compared old and young adults in an N + 2-boundary paradigm in which a nonword preview of word N + 2 or word N + 2 itself is replaced by the target word once the eyes cross an invisible boundary located after word N. The intermediate word N + I was always three letters long. Gaze durations on word N + 2 were significantly shorter for identical than nonword N + 2 preview both for young and for old adults, with no significant difference in this preview benefit. Young adults, however, did modulate their gaze duration on word N more strongly than old adults in response to the difficulty of the parafoveal word N + I. Taken together, the results suggest a dissociation of preview benefit and parafoveal-on-foveal effect. Results are discussed in terms of age-related decline in resilience towards distributed processing while simultaneously preserving the ability to integrate parafoveal information into foveal processing. As such, the present results relate to proposals of regulatory compensation strategies older adults use to secure an overall reading speed very similar to that of young adults. KW - age differences KW - perceptual span KW - preview benefit KW - parafoveal-on-foveal effect KW - compensation strategies Y1 - 2011 U6 - https://doi.org/10.1037/a0021616 SN - 0882-7974 VL - 26 IS - 2 SP - 451 EP - 460 PB - American Psychological Association CY - Washington ER - TY - JOUR A1 - Dimigen, Olaf A1 - Sommer, Werner A1 - Hohlfeld, Annette A1 - Jacobs, Arthur M. A1 - Kliegl, Reinhold T1 - Coregistration of eye movements and EEG in natural reading analyses and review JF - Journal of experimental psychology : General N2 - Brain-electric correlates of reading have traditionally been studied with word-by-word presentation, a condition that eliminates important aspects of the normal reading process and precludes direct comparisons between neural activity and oculomotor behavior. In the present study, we investigated effects of word predictability on eye movements (EM) and fixation-related brain potentials (FRPs) during natural sentence reading. Electroencephalogram (EEG) and EM (via video-based eye tracking) were recorded simultaneously while subjects read heterogeneous German sentences, moving their eyes freely over the text. FRPs were time-locked to first-pass reading fixations and analyzed according to the cloze probability of the currently fixated word. We replicated robust effects of word predictability on EMs and the N400 component in FRPs. The data were then used to model the relation among fixation duration, gaze duration, and N400 amplitude, and to trace the time course of EEG effects relative to effects in EM behavior. In an extended Methodological Discussion section, we review 4 technical and data-analytical problems that need to be addressed when FRPs are recorded in free-viewing situations (such as reading, visual search, or scene perception) and propose solutions. Results suggest that EEG recordings during normal vision are feasible and useful to consolidate findings from EEG and eye-tracking studies. KW - EEG KW - eye tracking KW - fixation-related potentials KW - artifact correction KW - natural viewing Y1 - 2011 U6 - https://doi.org/10.1037/a0023885 SN - 0096-3445 VL - 140 IS - 4 SP - 552 EP - 572 PB - American Psychological Association CY - Washington ER - TY - JOUR A1 - Ohl, Sven A1 - Brandt, Stephan A. A1 - Kliegl, Reinhold T1 - Secondary (micro-)saccades the influence of primary saccade end point and target eccentricity on the process of postsaccadic fixation JF - Vision research : an international journal for functional aspects of vision. N2 - We examine how the size of saccadic under-/overshoot and target eccentricity influence the latency, amplitude and orientation of secondary (micro-)saccades. In our experiment, a target appeared at an eccentricity of either 6 degrees or 14 degrees of visual angle. Subjects were instructed to direct their gaze as quickly as possible to the target and hold fixation at the new location until the end of the trial. Typically, increasing saccadic error is associated with faster and larger secondary saccades. We show that secondary saccades at distant in contrast to close targets have in a specific error range a shorter latency, larger amplitude, and follow more often the direction of the primary saccade. Finally, we demonstrate that an undershooting primary saccade is followed almost exclusively by secondary saccades into the same direction while overshooting primary saccades are followed by secondary saccades into both directions. This supports the notion that under- and overshooting imply different consequences for postsaccadic oculomotor processing. Results are discussed using a model, introduced by Rolfs, Kliegl, and Engbert (2008), to account for the generation of microsaccades. We argue that the dynamic interplay of target eccentricity and the magnitude of the saccadic under-/overshoot can be explained by a different strength of activation in the two hemispheres of the saccadic motor map in this model. KW - Secondary saccade KW - Microsaccade KW - Saccadic error KW - Error-correction KW - Target eccentricity Y1 - 2011 U6 - https://doi.org/10.1016/j.visres.2011.09.005 SN - 0042-6989 SN - 1878-5646 VL - 51 IS - 23-24 SP - 2340 EP - 2347 PB - Elsevier CY - Oxford ER - TY - CHAP A1 - Ohl, Sven A1 - Brandt, S. A1 - Kliegl, Reinhold T1 - Post-saccadic location judgments after presentation of multiple target-like objects T2 - Perception Y1 - 2012 SN - 0301-0066 SN - 1468-4233 VL - 41 IS - 1 SP - 171 EP - 171 PB - Sage Publ. CY - London ER - TY - CHAP A1 - Kliegl, Reinhold A1 - Matuschek, Hannes A1 - Holschneider, Matthias T1 - Multivariate analyses of fixation durations in reading with linear mixed and additive mixed models T2 - International journal of psychology Y1 - 2012 SN - 0020-7594 VL - 47 IS - 33 SP - 139 EP - 139 PB - Wiley CY - Hove ER - TY - CHAP A1 - Kliegl, Reinhold T1 - Eye movements during reading: Contributions of cross-language comparisons T2 - International journal of psychology Y1 - 2012 SN - 0020-7594 VL - 47 SP - 138 EP - 138 PB - Wiley CY - Hove ER - TY - JOUR A1 - Kliegl, Reinhold A1 - Dambacher, Michael A1 - Dimigen, Olaf A1 - Jacobs, Arthur M. A1 - Sommer, Werner T1 - Eye movements and brain electric potentials during reading JF - Psychological research : an international journal of perception, attention, memory, and action N2 - The development of theories and computational models of reading requires an understanding of processing constraints, in particular of timelines related to word recognition and oculomotor control. Timelines of word recognition are usually determined with event-related potentials (ERPs) recorded under conditions of serial visual presentation (SVP) of words; timelines of oculomotor control are derived from parameters of eye movements (EMs) during natural reading. We describe two strategies to integrate these approaches. One is to collect ERPs and EMs in separate SVP and natural reading experiments for the same experimental material (but different subjects). The other strategy is to co-register EMs and ERPs during natural reading from the same subjects. Both strategies yield data that allow us to determine how lexical properties influence ERPs (e.g., the N400 component) and EMs (e.g., fixation durations) across neighboring words. We review our recent research on the effects of frequency and predictability of words on both EM and ERP measures with reference to current models of eye-movement control during reading. Results are in support of the proposition that lexical access is distributed across several fixations and across brain-electric potentials measured on neighboring words. Y1 - 2012 U6 - https://doi.org/10.1007/s00426-011-0376-x SN - 0340-0727 VL - 76 IS - 2 SP - 145 EP - 158 PB - Springer CY - Heidelberg ER -