TY  - JOUR
A1  - Thiel, Marco
A1  - Romano, Maria Carmen
A1  - Kurths, Jürgen
A1  - Rolfs, Martin
A1  - Kliegl, Reinhold
T1  - Generating surrogates from recurrences
N2  - 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.
Y1  - 2008
UR  - http://rsta.royalsocietypublishing.org/
SN  - 1364-503X
ER  - 
TY  - JOUR
A1  - Moshel, Shay
A1  - Zivotofsky, Ari Z.
A1  - Liang, Jin-Rong
A1  - Engbert, Ralf
A1  - Kurths, Jürgen
A1  - Kliegl, Reinhold
A1  - Havlin, Shlomo
T1  - Persistence and phase synchronization properties of fixational eye movement
N2  - When we fixate our gaze on a stable object, our eyes move continuously with extremely small involuntary and autonomic movements, that even we are unaware of during their occurrence. One of the roles of these fixational eye movements is to prevent the adaptation of the visual system to continuous illumination and inhibit fading of the image. These random, small movements are restricted at long time scales so as to keep the target at the centre of the field of view. In addition, the synchronisation properties between both eyes are related to binocular coordination in order to provide stereopsis. We investigated the roles of different time scale behaviours, especially how they are expressed in the different spatial directions (vertical versus horizontal). We also tested the synchronisation between both eyes. Results show different scaling behaviour between horizontal and vertical movements. When the small ballistic movements, i.e., microsaccades, are removed, the scaling behaviour in both axes becomes similar. Our findings suggest that microsaccades enhance the persistence at short time scales mostly in the horizontal component and much less in the vertical component. We also applied the phase synchronisation decay method to study the synchronisation between six combinations of binocular fixational eye movement components. We found that the vertical-vertical components of right and left eyes are significantly more synchronised than the horizontal-horizontal components. These differences may be due to the need for continuously moving the eyes in the horizontal plane in order to match the stereoscopic image for different viewing distances.
Y1  - 2008
UR  - 1960 = DOI: 10.1140/epjst/e2008-00762-3
SN  - 1951-6355
ER  - 
TY  - JOUR
A1  - Baptista, Murilo da Silva
A1  - Bohn, Christiane
A1  - Kliegl, Reinhold
A1  - Engbert, Ralf
A1  - Kurths, Jürgen
T1  - Reconstruction of eye movements during blinks
Y1  - 2008
UR  - http://chaos.aip.org/
U6  - https://doi.org/10.1063/1.2890843
SN  - 1054-1500
ER  -