@article{RolfsLaubrockKliegl2008, author = {Rolfs, Martin and Laubrock, Jochen and Kliegl, Reinhold}, title = {Microsaccade-induced prolongation of saccadic latencies depends on microsaccade amplitude}, issn = {1995-8692}, year = {2008}, language = {en} } @article{LaubrockEngbertKliegl2008, author = {Laubrock, Jochen and Engbert, Ralf and Kliegl, Reinhold}, title = {Fixational eye movements predict the perceived direction of ambiguous apparent motion}, issn = {1534-7362}, doi = {10.1167/8.14.13}, year = {2008}, abstract = {Neuronal activity in area LIP is correlated with the perceived direction of ambiguous apparent motion (Z. M. Williams, J. C. Elfar, E. N. Eskandar, L. J. Toth, \& J. A. Assad, 2003). Here we show that a similar correlation exists for small eye movements made during fixation. A moving dot grid with superimposed fixation point was presented through an aperture. In a motion discrimination task, unambiguous motion was compared with ambiguous motion obtained by shifting the grid by half of the dot distance. In three experiments we show that (a) microsaccadic inhibition, i.e., a drop in microsaccade frequency precedes reports of perceptual flips, (b) microsaccadic inhibition does not accompany simple response changes, and (c) the direction of microsaccades occurring before motion onset biases the subsequent perception of ambiguous motion. We conclude that microsaccades provide a signal on which perceptual judgments rely in the absence of objective disambiguating stimulus information.}, 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} } @misc{KlieglRisseLaubrock2007, author = {Kliegl, Reinhold and Risse, Sarah and Laubrock, Jochen}, title = {Preview Benefit and Parafoveal-on-Foveal Effects from Word N+2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57186}, year = {2007}, abstract = {Using the gaze-contingent boundary paradigm with the boundary placed after word n, we manipulated preview of word n+2 for fixations on word n. There was no preview benefit for first-pass reading on word n+2, replicating the results of Rayner, Juhasz, and Brown (2007), but there was a preview benefit on the three-letter word n+1, that is, after the boundary, but before word n+2. Additionally, both word n+1 and word n+2 exhibited parafoveal-on-foveal effects on word n. Thus, during a fixation on word n and given a short word n+1, some information is extracted from word n+2, supporting the hypothesis of distributed processing in the perceptual span.}, language = {en} } @article{KlieglRisseLaubrock2007, author = {Kliegl, Reinhold and Risse, Sarah and Laubrock, Jochen}, title = {Preview benefit and parafoveal-on-foveal effects from word n+2}, issn = {0096-1523}, doi = {10.1037/0096-1523.33.5.1250}, year = {2007}, abstract = {Using the gaze-contingent boundary paradigm with the boundary placed after word n, the experiment manipulated preview of word n + 2 for fixations on word n. There was no preview benefit for 1st-pass reading on word n + 2, replicating the results of K. Rayner, B. J. Juhasz, and S. J. Brown (2007), but there was a preview benefit on the 3- letter word n + 1, that is, after the boundary but before word n + 2. Additionally, both word n + 1 and word n + 2 exhibited parafoveal-on-foveal effects on word n. Thus, during a fixation on word n and given a short word n + 1, some information is extracted from word n + 2, supporting the hypothesis of distributed processing in the perceptual span.}, 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{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{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{LaubrockEngbertKliegl2005, author = {Laubrock, Jochen and Engbert, Ralf and Kliegl, Reinhold}, title = {Microsaccade dynamics during covert attention}, issn = {0042-6989}, year = {2005}, abstract = {We compared effects of covert spatial-attention shifts induced with exogenous or endogenous cues on microsaccade rate and direction. Separate and dissociated effects were obtained in rate and direction measures. Display changes caused microsaccade rate inhibition, followed by sustained rate enhancement. Effects on microsaccade direction were differentially tied to cue class (exogenous vs. endogenous) and type (neutral vs. directional). For endogenous cues, direction effects were weak and occurred late. Exogenous cues caused a fast direction bias towards the cue (i.e., early automatic triggering of saccade programs), followed by a shift in the opposite direction (i.e, controlled inhibition of cue-directed saccades, leading to a 'leakage' of microsaccades in the opposite direction). (C) 2004 Elsevier Ltd. All rights reserved}, language = {en} } @article{LaubrockEngbertKliegl2005, author = {Laubrock, Jochen and Engbert, Ralf and Kliegl, Reinhold}, title = {Microsaccade rate during (un)ambiguous apparent motion}, issn = {0301-0066}, year = {2005}, language = {en} }