@article{ThielRomanoKurthsetal.2008, author = {Thiel, Marco and Romano, Maria Carmen and Kurths, J{\"u}rgen and Rolfs, Martin and Kliegl, Reinhold}, title = {Generating surrogates from recurrences}, issn = {1364-503X}, year = {2008}, 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 only one centre in the brain that produces the fixational movements in both eyes or a close link between the two centres.}, language = {en} } @article{RolfsEngbertKliegl2005, author = {Rolfs, Martin and Engbert, Ralf and Kliegl, Reinhold}, title = {Crossmodal coupling of oculomotor control and spatial attention in vision and audition}, issn = {0014-4819}, year = {2005}, abstract = {Fixational eye movements occur involuntarily during visual fixation of stationary scenes. The fastest components of these miniature eye movements are microsaccades, which can be observed about once per second. Recent studies demonstrated that microsaccades are linked to covert shifts of visual attention. Here, we generalized this finding in two ways. First, we used peripheral cues, rather than the centrally presented cues of earlier studies. Second, we spatially cued attention in vision and audition to visual and auditory targets. An analysis of microsaccade responses revealed an equivalent impact of visual and auditory cues on microsaccade-rate signature (i.e. an initial inhibition followed by an overshoot and a final return to the pre-cue baseline rate). With visual cues or visual targets, microsaccades were briefly aligned with cue direction and then opposite to cue direction during the overshoot epoch, probably as a result of an inhibition of an automatic saccade to the peripheral cue. With left auditory cues and auditory targets microsaccades oriented in cue direction. We argue that microsaccades can be used to study crossmodal integration of sensory information and to map the time course of saccade preparation during covert shifts of visual and auditory attention}, language = {en} } @article{KlieglGrabnerRolfsetal.2004, author = {Kliegl, Reinhold and Grabner, Ellen and Rolfs, Martin and Engbert, Ralf}, title = {Length, frequency, and predictability effects of words on eye movements in reading}, year = {2004}, language = {en} } @misc{DambacherRolfsGoellneretal.2009, author = {Dambacher, Michael and Rolfs, Martin and G{\"o}llner, Kristin and Kliegl, Reinhold and Jacobs, Arthur M.}, title = {Event-related potentials reveal rapid verification of predicted visual input}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44953}, year = {2009}, abstract = {Human information processing depends critically on continuous predictions about upcoming events, but the temporal convergence of expectancy-based top-down and input-driven bottom-up streams is poorly understood. We show that, during reading, event-related potentials differ between exposure to highly predictable and unpredictable words no later than 90 ms after visual input. This result suggests an extremely rapid comparison of expected and incoming visual information and gives an upper temporal bound for theories of top-down and bottom-up interactions in object recognition.}, 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{LaubrockKlieglRolfsetal.2010, author = {Laubrock, Jochen and Kliegl, Reinhold and Rolfs, Martin and Engbert, Ralf}, title = {When do microsaccades follow spatial attention?}, issn = {1943-3921}, doi = {10.3758/APP.72.3.683}, year = {2010}, abstract = {Following up on an exchange about the relation between microsaccades and spatial attention (Horowitz, Fencsik, Fine, Yurgenson, \& Wolfe, 2007; Horowitz, Fine, Fencsik, Yurgenson, \& Wolfe, 2007; Laubrock, Engbert, Rolfs, \& Kliegl, 2007), we examine the effects of selection criteria and response modality. We show that for Posner cuing with saccadic responses, microsaccades go with attention in at least 75\% of cases (almost 90\% if probability matching is assumed) when they are first (or only) microsaccades in the cue target interval and when they occur between 200 and 400 msec after the cue. The relation between spatial attention and the direction of microsaccades drops to chance level for unselected microsaccades collected during manual-response conditions. Analyses of data from four cross-modal cuing experiments demonstrate an above-chance, intermediate link for visual cues, but no systematic relation for auditory cues. Thus, the link between spatial attention and direction of microsaccades depends on the experimental condition and time of occurrence, but it can be very strong.}, 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} } @article{KinderRolfsKliegl2008, author = {Kinder, Annette and Rolfs, Martin and Kliegl, Reinhold}, title = {Sequence learning at optimal stimulus-response mapping : evidence from a serial reaction-time task}, doi = {10.1080/17470210701557555}, year = {2008}, abstract = {We propose a new version of the serial reaction time (SRT) task in which participants merely looked at the target instead of responding manually. As response locations were identical to target locations, stimulus - response compatibility was maximal in this task. We demonstrated that saccadic response times decreased during training and increased again when a new sequence was presented. It is unlikely that this effect was caused by stimulus - response (S - R) learning because bonds between (visual) stimuli and (oculomotor) responses were already well established before the experiment started. Thus, the finding shows that the building of S - R bonds is not essential for learning in the SRT task.}, language = {en} } @article{BoettcherRolfsKliegletal.2009, author = {B{\"o}ttcher, Heiko and Rolfs, Martin and Kliegl, Reinhold and Ihle, Wolfgang}, title = {Inattentional blindness and change blindness bei Jungen mit ADHS}, year = {2009}, language = {en} } @article{BoettcherRolfsKliegletal.2009, author = {B{\"o}ttcher, Heiko and Rolfs, Martin and Kliegl, Reinhold and Ihle, Wolfgang}, title = {Inattentional blindness and change blindness bei Jungen mit ADHS : Posterpr{\"a}sentation}, issn = {1616-3443}, doi = {10.1026/1616-3443.38.S1.20}, year = {2009}, language = {de} }