As for RDK backgrounds, the psychometric function for coherent motion sensitivity was biased toward the direction opposite to walking. Results indicated that the counterphase grating appeared to move in the direction opposite to that of walking in 75% of trials, significantly higher than chance level. In experiment 2, random dot kinematograms (RDK) with varying signal-noise ratios were used to evaluate sensitivity for coherent motion. 2-alternative forced choice method (left or right).
In experiment 1, observers judged motion direction of a counterphase grating with a.
To exemplify this phenomenon, we conducted two experiments presenting an ambiguous motion as a background of a point-lights walker stepping on a tread-mill. We found a new visual illusion caused by biological motion, in which a background pattern appears to move oppositely to a human locomotion indicated by gait.
#Walking papers illusion pro
A review and reanalysis here of the new evidence, pro and con, resolves the challenges and yields a more clearly defined and significantly strengthened theory. Meanwhile, eight apparent contradictions to the three-systems theory have been proposed. Various procedures have successfully discriminated between second- and third-order motion (when first-order motion is excluded): dual tasks, second-order reversed phi, motion competition, and selective adaptation. Subsequently, there have been some strongly confirmatory reports: different gain-control mechanisms for first- and second-order motion, selective impairment of first- versus second- and/or third-order motion by different brain injuries, and the classification of new third-order motions, e.g., isoluminant chromatic motion. Lu and Sperling proposed that human visual motion perception is served by three separate motion systems: a first-order system that responds to moving luminance patterns, a second-order system that responds to moving modulations of feature types-stimuli in which the expected luminance is the same everywhere but an area of higher contrast or of flicker moves, and a third-order system that computes the motion of marked locations in a "salience map," that is, a neural representation of visual space in which the locations of important visual features ("figure") are marked and "ground" is unmarked. This result led us to hypothesize that the backscroll illusion is generalized to objects that have shapes implying their moving directions. An additional experiment found a similar effect from a vehicle with rotating wheels but no induction from a rotating wheel per se. Thus, we concluded that the illusion was determined by the high-level recognition of biological motion. A weak but significant illusion was observed from a static figure that implied a gait. The time course showed that the illusion arose as if it was synchronized with gait recognition, and that it was sustained against several reversals of limb swings so that local motion accounts were denied. The induction was tuned to a gait velocity. The apparent grating motion was consistently induced in the direction opposite to the locomotion.
We confirmed this notion from psychophysical experiments that mainly presented a realistic human figure on a treadmill walking or running in front of a counterphase grating. This illusion is from the visual system registering retinal motion signals in relation to high-level object motion signals.
#Walking papers illusion movie
Backscroll illusion is an apparent motion perceived in backgrounds of movie images that present locomotive objects such as people, animals, and vehicles.
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