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Pattern randomness aftereffect.

Yamada Y, Kawabe T, Miyazaki M - Sci Rep (2013)

Bottom Line: Perceived randomness decreased (increased) following adaptation to high (low) physical randomness (Experiment 1).Our data were consistent with a model assuming filter-rectify-filter processing for orientation inputs.Thus, we infer that neural processing for orientation grouping/segregation underlies the perception of pattern randomness.

View Article: PubMed Central - PubMed

Affiliation: 1] Research Institute for Time Studies, Yamaguchi University, Yamaguchi, Yamaguchi, Japan [2].

ABSTRACT
Humans can easily discriminate a randomly spaced from a regularly spaced visual pattern. Here, we demonstrate that observers can adapt to pattern randomness. Following their adaption to prolonged exposure to two-dimensional patterns with varying levels of physical randomness, observers judged the randomness of the pattern. Perceived randomness decreased (increased) following adaptation to high (low) physical randomness (Experiment 1). Adaptation to 22.5°-rotated adaptor stimuli did not cause a randomness aftereffect (Experiment 2), suggesting that positional variation is unlikely to be responsible for the pattern randomness perception. Moreover, the aftereffect was not selective to contrast polarity (Experiment 3) and was not affected by spatial jitter (Experiment 4). Last, the aftereffect was not affected by adaptor configuration (Experiment 5). Our data were consistent with a model assuming filter-rectify-filter processing for orientation inputs. Thus, we infer that neural processing for orientation grouping/segregation underlies the perception of pattern randomness.

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Individual data in Experiment 4.The dashed line represents the physical randomness value of the test stimulus (i.e., with middle physical randomness) that was fixed through experiments. The error bars denote 95% confidence intervals calculated on the basis of the psi method.
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f5: Individual data in Experiment 4.The dashed line represents the physical randomness value of the test stimulus (i.e., with middle physical randomness) that was fixed through experiments. The error bars denote 95% confidence intervals calculated on the basis of the psi method.

Mentions: Figure 5 shows the results of Experiment 4. The data obtained in this experiment with spatial jitter in the overall position of the adaptor stimuli are presented as the jitter condition. For comparison, the data of the high-randomness condition of Experiment 1 are presented and here renamed as the no-jitter condition. The individual data show that the matched randomness of the test stimulus in the jitter condition was comparable with that in the no-jitter condition. Moreover, the 95% confidence intervals of the individual data indicate that the matched randomness in the jitter condition was significantly lower than the 0.39° that was the physical randomness value of the test stimulus (YY: a 30.2% decrease; TD: a 34.9% decrease; TO: a 12.6% decrease), confirming that the pattern randomness aftereffect occurred for each observer. These results suggest that jittering the overall positions of the adaptor stimuli did not affect the pattern randomness aftereffect.


Pattern randomness aftereffect.

Yamada Y, Kawabe T, Miyazaki M - Sci Rep (2013)

Individual data in Experiment 4.The dashed line represents the physical randomness value of the test stimulus (i.e., with middle physical randomness) that was fixed through experiments. The error bars denote 95% confidence intervals calculated on the basis of the psi method.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3795352&req=5

f5: Individual data in Experiment 4.The dashed line represents the physical randomness value of the test stimulus (i.e., with middle physical randomness) that was fixed through experiments. The error bars denote 95% confidence intervals calculated on the basis of the psi method.
Mentions: Figure 5 shows the results of Experiment 4. The data obtained in this experiment with spatial jitter in the overall position of the adaptor stimuli are presented as the jitter condition. For comparison, the data of the high-randomness condition of Experiment 1 are presented and here renamed as the no-jitter condition. The individual data show that the matched randomness of the test stimulus in the jitter condition was comparable with that in the no-jitter condition. Moreover, the 95% confidence intervals of the individual data indicate that the matched randomness in the jitter condition was significantly lower than the 0.39° that was the physical randomness value of the test stimulus (YY: a 30.2% decrease; TD: a 34.9% decrease; TO: a 12.6% decrease), confirming that the pattern randomness aftereffect occurred for each observer. These results suggest that jittering the overall positions of the adaptor stimuli did not affect the pattern randomness aftereffect.

Bottom Line: Perceived randomness decreased (increased) following adaptation to high (low) physical randomness (Experiment 1).Our data were consistent with a model assuming filter-rectify-filter processing for orientation inputs.Thus, we infer that neural processing for orientation grouping/segregation underlies the perception of pattern randomness.

View Article: PubMed Central - PubMed

Affiliation: 1] Research Institute for Time Studies, Yamaguchi University, Yamaguchi, Yamaguchi, Japan [2].

ABSTRACT
Humans can easily discriminate a randomly spaced from a regularly spaced visual pattern. Here, we demonstrate that observers can adapt to pattern randomness. Following their adaption to prolonged exposure to two-dimensional patterns with varying levels of physical randomness, observers judged the randomness of the pattern. Perceived randomness decreased (increased) following adaptation to high (low) physical randomness (Experiment 1). Adaptation to 22.5°-rotated adaptor stimuli did not cause a randomness aftereffect (Experiment 2), suggesting that positional variation is unlikely to be responsible for the pattern randomness perception. Moreover, the aftereffect was not selective to contrast polarity (Experiment 3) and was not affected by spatial jitter (Experiment 4). Last, the aftereffect was not affected by adaptor configuration (Experiment 5). Our data were consistent with a model assuming filter-rectify-filter processing for orientation inputs. Thus, we infer that neural processing for orientation grouping/segregation underlies the perception of pattern randomness.

Show MeSH
Related in: MedlinePlus