@article{OberauerKliegl2006, author = {Oberauer, Klaus and Kliegl, Reinhold}, title = {A formal model of capacity limits in working memory}, series = {Journal of Memory and Language}, volume = {55}, journal = {Journal of Memory and Language}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0749-596X}, doi = {10.1016/j.jml.2006.08.009}, pages = {601 -- 626}, year = {2006}, abstract = {A mathematical model of working-memory capacity limits is proposed on the key assumption of mutual interference between items in working memory. Interference is assumed to arise from overwriting of features shared by these items. The model was fit to time-accuracy data of memory-updating tasks from four experiments using nonlinear mixed effect (NLME) models as a framework. The model gave a good account of the data from a numerical and a spatial task version. The performance pattern in a combination of numerical and spatial updating could be explained by variations in the interference parameter: assuming less feature overlap between contents from different domains than between contents from the same domain, the model can account for double dissociations of content domains in dual-task experiments. Experiment 3 extended this idea to similarity within the verbal domain. The decline of memory accuracy with increasing memory load was steeper with phonologically similar than with dissimilar material, although processing speed was faster for the similar material. The model captured the similarity effects with a higher estimated interference parameter for the similar than for the dissimilar condition. The results are difficult to explain with alternative models, in particular models incorporating time-based decay and models assuming limited resource pools.}, language = {en} } @article{RichterEngbertKliegl2006, author = {Richter, Eike M. and Engbert, Ralf and Kliegl, Reinhold}, title = {Current advances in SWIFT}, issn = {1389-0417}, doi = {10.1016/j.cogsys.2005.07.003}, year = {2006}, abstract = {Models of eye movement control are very useful for gaining insights into the intricate connections of different cognitive and oculomotor subsystems involved in reading. The SWIFT model (Engbert, Longtin, \& Kliegl (2002). Vision Research, 42, 621 - 636) proposed a unified mechanism to account for all types of eye movement patterns that might be observed in reading behavior. The model is based on the notion of spatially distributed, or parallel, processing of words in a sentence. We present a refined version of SWIFT introducing a letter-based approach that proposes a processing gradient in the shape of a smooth function. We show that SWIFT extents its capabilities by accounting for distributions of landing positions.}, language = {en} } @article{DambacherKlieglHofmannetal.2006, author = {Dambacher, Michael and Kliegl, Reinhold and Hofmann, Markus and Jacobs, Arthur M.}, title = {Frequency and predictability effects on event-related potentials during reading}, issn = {0006-8993}, doi = {10.1016/j.brainres.2006.02.010}, year = {2006}, abstract = {Effects of frequency, predictability, and position of words on event-related potentials were assessed during word-by-word sentence reading in 48 subjects in an early and in a late time window corresponding to P200 and N400. Repeated measures multiple regression analyses revealed a P200 effect in the high-frequency range also the P200 was larger on words at the beginning and end of sentences than on words in the middle of sentences (i.e., a quadratic effect of word position). Predictability strongly affected the N400 component; the effect was stronger for low than for high- frequency words. The P200 frequency effect indicates that high-frequency words are lexically accessed very fast, independent of context information. Effects on the N400 suggest that predictability strongly moderates the late access especially of low-frequency words. Thus, contextual facilitation on the N400 appears to reflect both lexical and post- lexical stages of word recognition, questioning a strict classification into lexical and post-lexical processes.}, language = {en} } @misc{ThielRomanoKurthsetal.2006, author = {Thiel, Marco and Romano, Maria Carmen and Kurths, J{\"u}rgen and Rolfs, Martin and Kliegl, Reinhold}, title = {Generating Surrogates from Recurrences}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56906}, year = {2006}, abstract = {In this paper we present an approach to recover the dynamics from recurrences of a system and then generate (multivariate) twin surrogate (TS) trajectories. In contrast to other approaches, such as the linear-like surrogates, this technique produces surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system visiting the attractor in a different way. We show that these surrogates are well suited to test for complex synchronization, which makes it possible to systematically assess the reliability of synchronization analyses. We then apply the TS to study binocular fixational movements and find strong indications that the fixational movements of the left and right eye are phase synchronized. This result indicates that there might be one centre only in the brain that produces the fixational movements in both eyes or a close link between two centres.}, language = {en} } @article{RolfsLaubrockKliegl2006, author = {Rolfs, Martin and Laubrock, Jochen and Kliegl, Reinhold}, title = {Shortening and prolongation of saccade latencies following microsaccades}, doi = {10.1007/s00221-005-0148-1}, year = {2006}, abstract = {When the eyes fixate at a point in a visual scene, small saccades rapidly shift the image on the retina. The effect of these microsaccades on the latency of subsequent large-scale saccades may be twofold. First, microsaccades are associated with an enhancement of visual perception. Their occurrence during saccade target perception could, thus, decrease saccade latencies. Second, microsaccades are likely to indicate activity in fixation-related oculomotor neurons. These represent competitors to saccade-related cells in the interplay of gaze holding and shifting. Consequently, an increase in saccade latencies would be expected after microsaccades. Here, we present evidence for both aspects of microsaccadic impact on saccade latency. In a delayed response task, participants made saccades to visible or memorized targets. First, microsaccade occurrence up to 50 ms before target disappearance correlated with 18 ms (or 8\%) faster saccades to memorized targets. Second, if microsaccades occurred shortly (i.e., < 150 ms) before a saccade was required, mean saccadic reaction time in visual and memory trials was increased by about 40 ms (or 16\%). Hence, microsaccades can have opposite consequences for saccade latencies, pointing at a differential role of these fixational eye movements in the preparation of saccade motor programs}, language = {en} } @misc{RolfsLaubrockKliegl2006, author = {Rolfs, Martin and Laubrock, Jochen and Kliegl, Reinhold}, title = {Shortening and Prolongation of Saccade Latencies Following Microsaccades}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57012}, year = {2006}, abstract = {When the eyes fixate at a point in a visual scene, small saccades rapidly shift the image on the retina. The effect of these microsaccades on the latency of subsequent large-scale saccades may be twofold. First, microsaccades are associated with an enhancement of visual perception. Their occurrence during saccade target perception should, thus, decrease saccade latencies. On the other hand, microsaccades likely indicate activity in fixation-related oculomotor neurons. These represent competitors to saccade-related cells in the interplay of gaze holding and shifting. Consequently, an increase in saccade latencies after microsaccades would be expected. Here, we present evidence for both aspects of microsaccadic impact on saccade latency. In a delayed response task, participants made saccades to visible or memorized targets. First, microsaccade occurrence up to 50 ms before target disappearance correlated with 18 ms (or 8\%) faster saccades to memorized targets. Second, if microsaccades occurred shortly (i.e., < 150 ms) before a saccade was required, saccadic reaction times in visual and memory trials were increased by about 40 ms (or 16\%). Hence, microsaccades can have opposite consequences for saccade latencies, pointing at a differential role of these fixational eye movements in preparation of motor programs.}, language = {en} } @article{LaubrockKlieglEngbert2006, author = {Laubrock, Jochen and Kliegl, Reinhold and Engbert, Ralf}, title = {SWIFT explorations of age differences in eye movements during reading}, issn = {0149-7634}, doi = {10.1016/j.neubiorev.2006.06.013}, year = {2006}, language = {en} } @article{RomanoThielKurthsetal.2006, author = {Romano, Maria Carmen and Thiel, Marco and Kurths, J{\"u}rgen and Rolfs, Martin and Engbert, Ralf and Kliegl, Reinhold}, title = {Synchronization Analysis and Recurrence in Complex Systems}, isbn = {978-3-527-40623-4}, year = {2006}, language = {en} } @article{KlieglNuthmannEngbert2006, author = {Kliegl, Reinhold and Nuthmann, Antje and Engbert, Ralf}, title = {Tracking the mind during reading : the influence of past, present, and future words on fixation durations}, issn = {0096-3445}, doi = {10.1037/0096-3445.135.1.12}, year = {2006}, abstract = {Reading requires the orchestration of visual, attentional, language-related, and oculomotor processing constraints. This study replicates previous effects of frequency, predictability, and length of fixated words on fixation durations in natural reading and demonstrates new effects of these variables related to previous and next words. Results are based on fixation durations recorded from 222 persons, each reading 144 sentences. Such evidence for distributed processing of words across fixation durations challenges psycholinguistic immediacy-of-processing and eye- mind assumptions. Most of the time the mind processes several words in parallel at different perceptual and cognitive levels. Eye movements can help to unravel these processes}, language = {en} } @misc{KlieglNuthmannEngbert2006, author = {Kliegl, Reinhold and Nuthmann, Antje and Engbert, Ralf}, title = {Tracking the Mind During Reading: The Influence of Past, Present, and Future Words on Fixation Durations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57225}, year = {2006}, abstract = {Reading requires the orchestration of visual, attentional, language-related, and oculomotor processing constraints. This study replicates previous effects of frequency, predictability, and length of fixated words on fixation durations in natural reading and demonstrates new effects of these variables related to previous and next words. Results are based on fixation durations recorded from 222 persons, each reading 144 sentences. Such evidence for distributed processing of words across fixation durations challenges psycholinguistic immediacy-of-processing and eye-mind assumptions. Most of the time the mind processes several words in parallel at different perceptual and cognitive levels. Eye movements can help to unravel these processes.}, language = {en} } @article{ThielRomanoKurthsetal.2006, author = {Thiel, Marco and Romano, Maria Carmen and Kurths, J{\"u}rgen and Rolfs, Martin and Kliegl, Reinhold}, title = {Twin surrogates to test for complex synchronisation}, doi = {10.1209/epl/i2006-10147-0}, year = {2006}, abstract = {We present an approach to generate (multivariate) twin surrogates (TS) based on recurrence properties. This technique generates surrogates which correspond to an independent copy of the underlying system, i.e. they induce a trajectory of the underlying system starting at different initial conditions. We show that these surrogates are well suited to test for complex synchronisation and exemplify this for the paradigmatic system of Rossler oscillators. The proposed test enables to assess the statistical relevance of a synchronisation analysis from passive experiments which are typical in natural systems}, language = {en} } @article{HoernigWeskottKliegletal.2006, author = {H{\"o}rnig, Robin and Weskott, Thomas and Kliegl, Reinhold and Fanselow, Gisbert}, title = {Word order variation in spatial descriptions with adverbs}, issn = {0090-502X}, doi = {10.3758/BF03193264}, year = {2006}, abstract = {Previous research has shown that in a three-term spatial reasoning task, the second premise of a German premise pair is especially easy to comprehend if (1) the prepositional object rather than the grammatical subject denotes the given entity, and if (2) the term denoting the given entity precedes the term denoting the new entity. Accordingly, the second premise is easiest to comprehend with noncanonical word order-that is, with the prepositional object in preverbal position denoting the given entity (e.g., To the right of the given object is the new subject). This finding is explained in terms of contextual licensing of noncanonical word order. Here, we discuss and tested two alternative accounts of contextual licensing, given-new and partially ordered set relations (Poset). The given-new account claims that noncanonical word order is licensed by the term denoting the given entity preceding the term denoting the new entity. On the Poset account, noncanonical word order is licensed if the preverbal constituent introduces a new entity that stands in a transitive, irreflexive, and asymmetric relation to a given entity. Comprehension times for second premises with spatial adverbs in four different word orders support both accounts of contextual licensing; Poset licensing was stronger than given-new licensing.}, language = {en} }