Art and Perception
Looking at Op Art: Gaze stability and motion illusions
Laboratory of Experimental Psychology, University of Leuven, Belgium; and Department of Psychology, Royal Holloway, University of London, UK [Present address: School of Psychology, University of Aberdeen, UK]
Department of Psychology, Royal Holloway, University of London, UK
Various Op artists have used simple geometrical patterns to create the illusion of motion in their artwork. One explanation for the observed illusion involves retinal shifts caused by small involuntary eye movements that observers make while they try to maintain fixation. Earlier studies have suggested a prominent role of the most conspicuous of these eye movements, small rapid position shifts called microsaccades. Here, we present data that could expand this view with a different interpretation. In three experiments, we recorded participants’ eye movements while they tried to maintain visual fixation when being presented with variants of Bridget Riley’s Fall, which were manipulated such as to vary the strength of induced motion. In the first two experiments, we investigated the properties of microsaccades for a set of stimuli with known motion strengths. In agreement with earlier observations, microsaccade rates were unaffected by the stimulus pattern and, consequently, the strength of induced motion illusion. In the third experiment, we varied the stimulus pattern across a larger range of parameters and asked participants to rate the perceived motion illusion. The results revealed that motion illusions in patterns resembling Riley’s Fall are perceived even in the absence of microsaccades, and that the reported strength of the illusion decreased with the number of microsaccades in the trial. Together, the three experiments suggest that other sources of retinal image instability than microsaccades, such as slow oculomotor drift, should be considered as possible factors contributing to the illusion.
Hermens F, Zanker J,
2012, "Looking at Op Art: Gaze stability and motion illusions" i-Perception 3(5) 282–304
Download citation data in RIS format
ISSN: 2041-6695 (electronic only)
Copyright: Copyright is retained by the author(s) of this article. This open-access article is distributed under a Creative Commons Licence, which permits noncommercial use, distribution, and reproduction, provided the original author(s) and source are credited and no alterations are made.