@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}
}
@article{RolfsEngbertKliegl2004,
  author    = {Rolfs, Martin and Engbert, Ralf and Kliegl, Reinhold},
  title     = {Microsaccade orientation supports attentional enhancement opposite to a peripheral cue},
  year      = {2004},
  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{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{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{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}
}
@phdthesis{Rolfs2007,
  author    = {Rolfs, Martin},
  title     = {In-between fixation and movement : on the generation of microsaccades and what they convey about saccade generation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14581},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {Microsaccades are an important component of the small eye movements that constitute fixation, the basis of visual perception. The specific function of microsaccades has been a long-standing research problem. Only recently, conclusive evidence emerged, showing that microsaccades aid both visual perception and oculomotor control. The main goal of this thesis was to improve our understanding of the implementation of microsaccade generation within the circuitry of saccade control, an unsolved issue in oculomotor research. We make a case for a model according to which microsaccades and saccades result from mutually dependent motor plans, competing for expression. The model consists of an activation field, coding for fixation at its center and for saccades at peripheral locations; saccade amplitude increases with eccentricity. Activity during fixation spreads to slightly peripheral locations in the field and, thus, may result in the generation of microsaccades. Inhibition of remote and excitation of neighbouring locations govern the dynamics of the field, resulting in a strong competition between fixation and saccade generation. We propose that this common-field model of microsaccade and saccade generation finds a neurophysiological counterpart in the motor map of the superior colliculus (SC), a key brainstem structure involved in the generation of saccades. In a series of five behavioral experiments, we tested implications of the model. Predictions were derived concerning (1) the behavior of microsaccades in a given task (microsaccade rate, amplitude, and direction), (2) the interactions of microsaccades and subsequent saccades, and (3) the relationship between microsaccadic behavior and neurophysiological processes at the level of the SC. The results yielded strong support for the model at all three levels of analysis, suggesting that microsaccade statistics are indicative of the state of the fixation-related part of the SC motor map.},
  language  = {en}
}
@article{LaubrockEngbertRolfsetal.2007,
  author    = {Laubrock, Jochen and Engbert, Ralf and Rolfs, Martin and Kliegl, Reinhold},
  title     = {Microsaccades are an index of covert attention : commentary on Horowitz, Fine, Fencsik, Yurgenson and Wolfe},
  issn      = {0956-7976},
  doi       = {10.1111/j.1467-9280.2007.01904.x},
  year      = {2007},
  language  = {en}
}
@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{RolfsKlieglEngbert2008,
  author    = {Rolfs, Martin and Kliegl, Reinhold and Engbert, Ralf},
  title     = {Toward a model of microsaccade generation : the case of microsaccadic inhibition},
  issn      = {1534-7362},
  doi       = {10.1167/8.11.5},
  year      = {2008},
  language  = {en}
}