Limits...
Eye movement instructions modulate motion illusion and body sway with Op Art.

Kapoula Z, Lang A, Vernet M, Locher P - Front Hum Neurosci (2015)

Bottom Line: Op Art generates illusory visual motion.Twenty-eight healthy adults in orthostatic stance were successively exposed to three visual stimuli consisting of one figure representing a cross (baseline condition) and two Op Art paintings providing sense of motion in depth-Bridget Riley's Movements in Squares and Akiyoshi Kitaoka's Rollers.Posture was measured for 30 s per condition using a body fixed sensor (accelerometer).

View Article: PubMed Central - PubMed

Affiliation: IRIS Team, Physiopathology of Binocular Motor Control and Vision, Neurosciences, UFR Biomédicale, CNRS, University Paris V Paris, France.

ABSTRACT
Op Art generates illusory visual motion. It has been proposed that eye movements participate in such illusion. This study examined the effect of eye movement instructions (fixation vs. free exploration) on the sensation of motion as well as the body sway of subjects viewing Op Art paintings. Twenty-eight healthy adults in orthostatic stance were successively exposed to three visual stimuli consisting of one figure representing a cross (baseline condition) and two Op Art paintings providing sense of motion in depth-Bridget Riley's Movements in Squares and Akiyoshi Kitaoka's Rollers. Before their exposure to the Op Art images, participants were instructed either to fixate at the center of the image (fixation condition) or to explore the artwork (free viewing condition). Posture was measured for 30 s per condition using a body fixed sensor (accelerometer). The major finding of this study is that the two Op Art paintings induced a larger antero-posterior body sway both in terms of speed and displacement and an increased motion illusion in the free viewing condition as compared to the fixation condition. For body sway, this effect was significant for the Riley painting, while for motion illusion this effect was significant for Kitaoka's image. These results are attributed to macro-saccades presumably occurring under free viewing instructions, and most likely to the small vergence drifts during fixations following the saccades; such movements in interaction with visual properties of each image would increase either the illusory motion sensation or the antero-posterior body sway.

No MeSH data available.


Related in: MedlinePlus

Body sway variables’ mean values and standard error for Riley’s and Kitaoka’s paintings in both viewing conditions (free viewing vs. fixation) (**p < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4374464&req=5

Figure 3: Body sway variables’ mean values and standard error for Riley’s and Kitaoka’s paintings in both viewing conditions (free viewing vs. fixation) (**p < 0.01).

Mentions: Means and standard errors for the six body sway variables are shown in Figure 3 as a function of the two artworks seen in both viewing conditions. These values are also summarized in Table 2. All body sway parameters for Riley’s and Kitaoka’s paintings were compared with a Wilcoxon test that revealed no statistically significant differences (Wilcoxon test, all z < 0.94; p > 0.35); as can be seen in Figure 3, any two black bars are very similar, and any two white bars are also very similar. These data were also compared as a function of viewing conditions (free viewing vs. fixation) using a Mann-Whitney U-test. As illustrated in Figure 3, the antero-posterior body sway for the Riley painting was found to be significantly higher in the free viewing condition than in the fixation condition, and this was the case both in terms of amplitude and velocity (U = 29 and 36, respectively, p = 0.0035, after Bonferroni correction p = 0.021). Interestingly, the difference was significant for both antero-posterior variables for Riley’s painting but failed to achieve significance for Kitaoka’s painting. However, it should be noted that, as seen in Table 2, antero-posterior body movement was somewhat higher, on average, for both paintings compared to medio-lateral body sway. Antero-posterior movement is indicative of the illusion of movement in depth and many participants during debriefing agreed that the images, especially the work by Kitaoka, produced a sense of motion in depth. All other comparisons for the remaining postural parameters shown in Table 2, were not significant (U > 45, p > 0.076, after Bonferroni correction p > 0.45).


Eye movement instructions modulate motion illusion and body sway with Op Art.

Kapoula Z, Lang A, Vernet M, Locher P - Front Hum Neurosci (2015)

Body sway variables’ mean values and standard error for Riley’s and Kitaoka’s paintings in both viewing conditions (free viewing vs. fixation) (**p < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4374464&req=5

Figure 3: Body sway variables’ mean values and standard error for Riley’s and Kitaoka’s paintings in both viewing conditions (free viewing vs. fixation) (**p < 0.01).
Mentions: Means and standard errors for the six body sway variables are shown in Figure 3 as a function of the two artworks seen in both viewing conditions. These values are also summarized in Table 2. All body sway parameters for Riley’s and Kitaoka’s paintings were compared with a Wilcoxon test that revealed no statistically significant differences (Wilcoxon test, all z < 0.94; p > 0.35); as can be seen in Figure 3, any two black bars are very similar, and any two white bars are also very similar. These data were also compared as a function of viewing conditions (free viewing vs. fixation) using a Mann-Whitney U-test. As illustrated in Figure 3, the antero-posterior body sway for the Riley painting was found to be significantly higher in the free viewing condition than in the fixation condition, and this was the case both in terms of amplitude and velocity (U = 29 and 36, respectively, p = 0.0035, after Bonferroni correction p = 0.021). Interestingly, the difference was significant for both antero-posterior variables for Riley’s painting but failed to achieve significance for Kitaoka’s painting. However, it should be noted that, as seen in Table 2, antero-posterior body movement was somewhat higher, on average, for both paintings compared to medio-lateral body sway. Antero-posterior movement is indicative of the illusion of movement in depth and many participants during debriefing agreed that the images, especially the work by Kitaoka, produced a sense of motion in depth. All other comparisons for the remaining postural parameters shown in Table 2, were not significant (U > 45, p > 0.076, after Bonferroni correction p > 0.45).

Bottom Line: Op Art generates illusory visual motion.Twenty-eight healthy adults in orthostatic stance were successively exposed to three visual stimuli consisting of one figure representing a cross (baseline condition) and two Op Art paintings providing sense of motion in depth-Bridget Riley's Movements in Squares and Akiyoshi Kitaoka's Rollers.Posture was measured for 30 s per condition using a body fixed sensor (accelerometer).

View Article: PubMed Central - PubMed

Affiliation: IRIS Team, Physiopathology of Binocular Motor Control and Vision, Neurosciences, UFR Biomédicale, CNRS, University Paris V Paris, France.

ABSTRACT
Op Art generates illusory visual motion. It has been proposed that eye movements participate in such illusion. This study examined the effect of eye movement instructions (fixation vs. free exploration) on the sensation of motion as well as the body sway of subjects viewing Op Art paintings. Twenty-eight healthy adults in orthostatic stance were successively exposed to three visual stimuli consisting of one figure representing a cross (baseline condition) and two Op Art paintings providing sense of motion in depth-Bridget Riley's Movements in Squares and Akiyoshi Kitaoka's Rollers. Before their exposure to the Op Art images, participants were instructed either to fixate at the center of the image (fixation condition) or to explore the artwork (free viewing condition). Posture was measured for 30 s per condition using a body fixed sensor (accelerometer). The major finding of this study is that the two Op Art paintings induced a larger antero-posterior body sway both in terms of speed and displacement and an increased motion illusion in the free viewing condition as compared to the fixation condition. For body sway, this effect was significant for the Riley painting, while for motion illusion this effect was significant for Kitaoka's image. These results are attributed to macro-saccades presumably occurring under free viewing instructions, and most likely to the small vergence drifts during fixations following the saccades; such movements in interaction with visual properties of each image would increase either the illusory motion sensation or the antero-posterior body sway.

No MeSH data available.


Related in: MedlinePlus