Voluntary tracking the moving clouds : Effects of speed variability on human smooth pursuit
We have previously investigated the human ocular following responses to a novel class of broadband random-texture stimuli, the Motion Clouds which have naturalistic spatiotemporal frequency spectrum (Sanz-Leon et al. 2012). Motion clouds allow manipulating the proportion of signal and noise and the detailed input distributions along a spatiotemporal continuum. In particular, we showed that reflexive tracking precision increases with the spatial and temporal frequency bandwidth for a given mean speed (Simoncini et al. 2012). Here, we extended this approach to voluntary tracking in order to investigate the effects of speed bandwidth (i.e. the variability of local speed around the mean value) on the different phases of smooth pursuit eye movements with Motion Clouds. Subjects were asked to track a large (either full-field or 5°-diameter patch) moving cloud stimulus, presented with three mean speed (5, 10 and 20°/s) and different speed bandwidths. We show that lower speed variability resulted in stronger initial eye acceleration. Pursuit gain during the steady-state phase was also dependent upon image speed variability. This study probes how global motion speed is estimated by the visual system and how the precision of voluntary pursuit eye movements depends upon the variability of the motion input.
Meeting abstract presented at ECVP 2016
- Kiana Mansour Pour, Laurent U. Perrinet, Guillaume S. Masson, Anna Montagnini. Voluntary tracking the moving clouds : Effects of speed variability on human smooth pursuit , URL . In Proceedings of ECVP, pages 2P045. 2016 abstract
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This work was supported by the Innovative Training Network "Perception and Action in Complex Environments" (PACE ITN), a Marie Skodowska-Curie program of the H2020 European Union program (grant agreement No 642961).