TY  - JOUR
A1  - Sinn, Petra
A1  - Engbert, Ralf
T1  - Saccadic facilitation by modulation of microsaccades in natural backgrounds
JF  - Attention, perception, & psychophysics : AP&P ; a journal of the Psychonomic Society, Inc.
N2  - Saccades move objects of interest into the center of the visual field for high-acuity visual analysis. White, Stritzke, and Gegenfurtner (Current Biology, 18, 124-128, 2008) have shown that saccadic latencies in the context of a structured background are much shorter than those with an unstructured background at equal levels of visibility. This effect has been explained by possible preactivation of the saccadic circuitry whenever a structured background acts as a mask for potential saccade targets. Here, we show that background textures modulate rates of microsaccades during visual fixation. First, after a display change, structured backgrounds induce a stronger decrease of microsaccade rates than do uniform backgrounds. Second, we demonstrate that the occurrence of a microsaccade in a critical time window can delay a subsequent saccadic response. Taken together, our findings suggest that microsaccades contribute to the saccadic facilitation effect, due to a modulation of microsaccade rates by properties of the background.
KW  - Eye movements
KW  - Microsaccade
KW  - Saccade latency
KW  - Background texture
KW  - Saccadic facilitation effect
Y1  - 2011
U6  - https://doi.org/10.3758/s13414-011-0107-9
SN  - 1943-3921
VL  - 73
IS  - 4
SP  - 1029
EP  - 1033
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Ohl, Sven
A1  - Brandt, Stephan A.
A1  - Kliegl, Reinhold
T1  - Secondary (micro-)saccades the influence of primary saccade end point and target eccentricity on the process of postsaccadic fixation
JF  - Vision research : an international journal for functional aspects of vision.
N2  - We examine how the size of saccadic under-/overshoot and target eccentricity influence the latency, amplitude and orientation of secondary (micro-)saccades. In our experiment, a target appeared at an eccentricity of either 6 degrees or 14 degrees of visual angle. Subjects were instructed to direct their gaze as quickly as possible to the target and hold fixation at the new location until the end of the trial. Typically, increasing saccadic error is associated with faster and larger secondary saccades. We show that secondary saccades at distant in contrast to close targets have in a specific error range a shorter latency, larger amplitude, and follow more often the direction of the primary saccade. Finally, we demonstrate that an undershooting primary saccade is followed almost exclusively by secondary saccades into the same direction while overshooting primary saccades are followed by secondary saccades into both directions. This supports the notion that under- and overshooting imply different consequences for postsaccadic oculomotor processing. Results are discussed using a model, introduced by Rolfs, Kliegl, and Engbert (2008), to account for the generation of microsaccades. We argue that the dynamic interplay of target eccentricity and the magnitude of the saccadic under-/overshoot can be explained by a different strength of activation in the two hemispheres of the saccadic motor map in this model.
KW  - Secondary saccade
KW  - Microsaccade
KW  - Saccadic error
KW  - Error-correction
KW  - Target eccentricity
Y1  - 2011
U6  - https://doi.org/10.1016/j.visres.2011.09.005
SN  - 0042-6989
SN  - 1878-5646
VL  - 51
IS  - 23-24
SP  - 2340
EP  - 2347
PB  - Elsevier
CY  - Oxford
ER  -