@article{YanKliegl2016,
  author    = {Yan, Ming and Kliegl, Reinhold},
  title     = {CarPrice versus CarpRice: Word Boundary Ambiguity Influences Saccade Target Selection During the Reading of Chinese Sentences},
  series = {Journal of experimental psychology : Learning, memory, and cognition},
  volume    = {42},
  journal   = {Journal of experimental psychology : Learning, memory, and cognition},
  publisher = {American Psychological Association},
  address   = {Washington},
  issn      = {0278-7393},
  doi       = {10.1037/xlm0000276},
  pages     = {1832 -- 1838},
  year      = {2016},
  abstract  = {As a contribution to a theoretical debate about the degree of high-level influences on saccade targeting during sentence reading, we investigated eye movements during the reading of structurally ambiguous Chinese character strings and examined whether parafoveal word segmentation could influence saccade-target selection. As expected, ambiguous strings took longer to process. More critically there were theoretically relevant interactions between ambiguity and launch site when first-fixation location and saccade amplitude served as dependent variables: Ambiguous strings in the parafovea triggered longer saccades and more rightward fixations for close launch sites than unambiguous ones; the reverse result was obtained for far launch sites. These crossover interactions indicate that parafoveal word segmentation influences saccade generation in Chinese and provide support of the hypothesis that high-level information can be involved in the decision about where to fixate next.},
  language  = {en}
}
@article{OhlWohltatKliegletal.2016,
  author    = {Ohl, Sven and Wohltat, Christian and Kliegl, Reinhold and Pollatos, Olga and Engbert, Ralf},
  title     = {Microsaccades Are Coupled to Heartbeat},
  series = {The journal of neuroscience},
  volume    = {36},
  journal   = {The journal of neuroscience},
  publisher = {Society for Neuroscience},
  address   = {Washington},
  issn      = {0270-6474},
  doi       = {10.1523/JNEUROSCI.2211-15.2016},
  pages     = {1237 -- 1241},
  year      = {2016},
  abstract  = {During visual fixation, the eye generates microsaccades and slower components of fixational eye movements that are part of the visual processing strategy in humans. Here, we show that ongoing heartbeat is coupled to temporal rate variations in the generation of microsaccades. Using coregistration of eye recording and ECG in humans, we tested the hypothesis that microsaccade onsets are coupled to the relative phase of the R-R intervals in heartbeats. We observed significantly more microsaccades during the early phase after the R peak in the ECG. This form of coupling between heartbeat and eye movements was substantiated by the additional finding of a coupling between heart phase and motion activity in slow fixational eye movements; i.e., retinal image slip caused by physiological drift. Our findings therefore demonstrate a coupling of the oculomotor system and ongoing heartbeat, which provides further evidence for bodily influences on visuomotor functioning.},
  language  = {en}
}
@article{OhlKliegl2016,
  author    = {Ohl, Sven and Kliegl, Reinhold},
  title     = {Revealing the time course of signals influencing the generation of},
  series = {Vision research : an international journal for functional aspects of vision.},
  volume    = {124},
  journal   = {Vision research : an international journal for functional aspects of vision.},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0042-6989},
  doi       = {10.1016/j.visres.2016.06.007},
  pages     = {52 -- 58},
  year      = {2016},
  abstract  = {Saccadic eye movements are frequently followed by smaller secondary saccades which are generally assumed to correct for the error in primary saccade landing position. However, secondary saccades can also occur after accurate primary saccades and they are often as small as microsaccades, therefore raising the need to further scrutinize the processes involved in secondary saccade generation. Following up a previous study, we analyzed secondary saccades using rate analysis which allows us to quantify experimental effects as shifts in distributions, therefore going beyond comparisons of mean differences. We use Aalen's additive hazards model to delineate the time course of key influences on the secondary saccade rate. In addition to the established effect of primary saccade error, we observed a time-varying influence of under- vs. overshooting - with a higher risk of generating secondary saccades following undershoots. Moreover, increasing target eccentricity influenced the programming of secondary saccades, therefore demonstrating that error-unrelated variables co-determine secondary saccade programs. Our results provide new insights into the generative mechanisms of small saccades during postsaccadic fixation that need to be accounted for by secondary saccade models.},
  language  = {en}
}
@article{NuthmannVituEngbertetal.2016,
  author    = {Nuthmann, Antje and Vitu, Francoise and Engbert, Ralf and Kliegl, Reinhold},
  title     = {No Evidence for a Saccadic Range Effect for Visually Guided and Memory-Guided Saccades in Simple Saccade-Targeting Tasks},
  series = {PLoS one},
  volume    = {11},
  journal   = {PLoS one},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0162449},
  pages     = {9935 -- 9943},
  year      = {2016},
  abstract  = {Saccades to single targets in peripheral vision are typically characterized by an undershoot bias. Putting this bias to a test, Kapoula [1] used a paradigm in which observers were presented with two different sets of target eccentricities that partially overlapped each other. Her data were suggestive of a saccadic range effect (SRE): There was a tendency for saccades to overshoot close targets and undershoot far targets in a block, suggesting that there was a response bias towards the center of eccentricities in a given block. Our Experiment 1 was a close replication of the original study by Kapoula [1]. In addition, we tested whether the SRE is sensitive to top-down requirements associated with the task, and we also varied the target presentation duration. In Experiments 1 and 2, we expected to replicate the SRE for a visual discrimination task. The simple visual saccade-targeting task in Experiment 3, entailing minimal top-down influence, was expected to elicit a weaker SRE. Voluntary saccades to remembered target locations in Experiment 3 were expected to elicit the strongest SRE. Contrary to these predictions, we did not observe a SRE in any of the tasks. Our findings complement the results reported by Gillen et al. [2] who failed to find the effect in a saccade-targeting task with a very brief target presentation. Together, these results suggest that unlike arm movements, saccadic eye movements are not biased towards making saccades of a constant, optimal amplitude for the task.},
  language  = {en}
}
@misc{HohensteinMatuschekKliegl2016,
  author    = {Hohenstein, Sven and Matuschek, Hannes and Kliegl, Reinhold},
  title     = {Linked linear mixed models},
  series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe},
  number    = {552},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-42828},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428281},
  pages     = {15},
  year      = {2016},
  abstract  = {The complexity of eye-movement control during reading allows measurement of many dependent variables, the most prominent ones being fixation durations and their locations in words. In current practice, either variable may serve as dependent variable or covariate for the other in linear mixed models (LMMs) featuring also psycholinguistic covariates of word recognition and sentence comprehension. Rather than analyzing fixation location and duration with separate LMMs, we propose linking the two according to their sequential dependency. Specifically, we include predicted fixation location (estimated in the first LMM from psycholinguistic covariates) and its associated residual fixation location as covariates in the second, fixation-duration LMM. This linked LMM affords a distinction between direct and indirect effects (mediated through fixation location) of psycholinguistic covariates on fixation durations. Results confirm the robustness of distributed processing in the perceptual span. They also offer a resolution of the paradox of the inverted optimal viewing position (IOVP) effect (i.e., longer fixation durations in the center than at the beginning and end of words) although the opposite (i.e., an OVP effect) is predicted from default assumptions of psycholinguistic processing efficiency: The IOVP effect in fixation durations is due to the residual fixation-location covariate, presumably driven primarily by saccadic error, and the OVP effect (at least the left part of it) is uncovered with the predicted fixation-location covariate, capturing the indirect effects of psycholinguistic covariates. We expect that linked LMMs will be useful for the analysis of other dynamically related multiple outcomes, a conundrum of most psychonomic research.},
  language  = {en}
}
@article{GoetheOberauerKliegl2016,
  author    = {G{\"o}the, Katrin and Oberauer, Klaus and Kliegl, Reinhold},
  title     = {Eliminating dual-task costs by minimizing crosstalk between tasks: The role of modality and feature pairings},
  series = {Cognition : international journal of cognitive science},
  volume    = {150},
  journal   = {Cognition : international journal of cognitive science},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0010-0277},
  doi       = {10.1016/j.cognition.2016.02.003},
  pages     = {92 -- 108},
  year      = {2016},
  abstract  = {We tested the independent influences of two content-based factors on dual-task costs, and on the parallel processing ability: The pairing of S-R modalities and the pairing of relevant features between stimuli and responses of two tasks. The two pairing factors were realized across four dual-task groups. Within each group the two tasks comprised two different stimulus modalities (visual and auditory), two different relevant stimulus features (spatial and verbal) and two response modalities (manual and vocal). Pairings of S-R modalities (standard: visual-manual and auditory-vocal, non-standard: visual-vocal and auditory manual) and feature pairings (standard: spatial-manual and verbal-vocal, non-standard: spatial-vocal and verbal-manual) varied across groups. All participants practiced their respective dual-task combination in a paradigm with simultaneous stimulus onset before being transferred to a psychological refractory period paradigm varying stimulus-onset asynchrony. A comparison at the end of practice revealed similar dual-task costs and similar pairing effects in both paradigms. Dual-task costs depended on modality and feature pairings. Groups training with non-standard feature pairings (i.e., verbal stimulus features mapped to spatially separated response keys, or spatial stimulus features mapped to verbal responses) and non-standard modality pairings (i.e., auditory stimulus mapped to manual response, or visual stimulus mapped to vocal responses) had higher dual-task costs than respective standard pairings. In contrast, irrespective of modality pairing dual-task costs virtually disappeared with standard feature pairings after practice in both paradigms. The results can be explained by crosstalk between feature-binding processes for the two tasks. Crosstalk was present for non-standard but absent for standard feature pairings. Therefore, standard feature pairings enabled parallel processing at the end of practice. (C) 2016 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{BeurskensMuehlbauerGrabowetal.2016,
  author    = {Beurskens, Rainer and M{\"u}hlbauer, Thomas and Grabow, Lena and Kliegl, Reinhold and Granacher, Urs},
  title     = {Effects of Backpack Carriage on Dual-Task Performance in Children During Standing and Walking},
  series = {Journal of motor behavior},
  volume    = {48},
  journal   = {Journal of motor behavior},
  publisher = {Wiley-VCH},
  address   = {Abingdon},
  issn      = {0022-2895},
  doi       = {10.1080/00222895.2016.1152137},
  pages     = {500 -- 508},
  year      = {2016},
  language  = {en}
}
@misc{BeurskensHaegerKliegletal.2016,
  author    = {Beurskens, Rainer and Haeger, Matthias and Kliegl, Reinhold and Roecker, Kai and Granacher, Urs},
  title     = {Postural Control in Dual-Task Situations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96638},
  pages     = {1 -- 15},
  year      = {2016},
  abstract  = {Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single- (ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 ± 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2-21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9-2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3-4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9-3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.},
  language  = {en}
}
@article{BeurskensHaegerKliegletal.2016,
  author    = {Beurskens, Rainer and Haeger, Matthias and Kliegl, Reinhold and Roecker, Kai and Granacher, Urs},
  title     = {Postural Control in Dual-Task Situations},
  series = {PLoS one},
  volume    = {11},
  journal   = {PLoS one},
  number    = {1},
  publisher = {PLoS},
  address   = {Lawrence, Kan.},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0147392},
  pages     = {1 -- 15},
  year      = {2016},
  abstract  = {Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single- (ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 ± 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2-21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9-2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3-4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9-3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.},
  language  = {en}
}
@article{BeurskensHaegerKliegletal.2016,
  author    = {Beurskens, Rainer and Haeger, Matthias and Kliegl, Reinhold and Roecker, Kai and Granacher, Urs},
  title     = {Postural Control in Dual-Task Situations: Does Whole-Body Fatigue Matter?},
  series = {PLoS one},
  volume    = {11},
  journal   = {PLoS one},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0147392},
  pages     = {1379 -- 1384},
  year      = {2016},
  abstract  = {Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single-(ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 +/- 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2-21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9-2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3-4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9-3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.},
  language  = {en}
}