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Processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia.

Tang Y, Liu C, Liu Z, Hu X, Yu YQ, Zhou Y - PLoS ONE (2014)

Bottom Line: We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies.In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings.These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Brain Function and Diseases, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, People's Republic of China; Research and Treatment Center of Amblyopia and Strabismus, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.

ABSTRACT
Several studies have indicated substantial processing deficits for static second-order stimuli in amblyopia. However, less is known about the perception of second-order moving gratings. To investigate this issue, we measured the contrast sensitivity for second-order (contrast-modulated) moving gratings in seven anisometropic amblyopes and ten normal controls. The measurements were performed with non-equated carriers and a series of equated carriers. For comparison, the sensitivity for first-order motion and static second-order stimuli was also measured. Most of the amblyopic eyes (AEs) showed reduced sensitivity for second-order moving gratings relative to their non-amblyopic eyes (NAEs) and the dominant eyes (CEs) of normal control subjects, even when the detectability of the noise carriers was carefully controlled, suggesting substantial processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia. In contrast, the non-amblyopic eyes of the anisometropic amblyopes were relatively spared. As a group, NAEs showed statistically comparable performance to CEs. We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies. In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings. These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia.

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Illustration of stimuli used in this experiment.(a) noise carrier, (b) first-order stimulus, (c) second-order stimulus. All stimuli are presented at screen center, subtended 2.51°×2.51°.
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pone-0113400-g001: Illustration of stimuli used in this experiment.(a) noise carrier, (b) first-order stimulus, (c) second-order stimulus. All stimuli are presented at screen center, subtended 2.51°×2.51°.

Mentions: The noise carrier (Figure 1a) was a 1-bit, spatially 2-d, static noise pattern generated by assigning individual (single) screen pixels (0.025 degree of visual angle) to be either ‘white’ or ‘black’ with equal probability to ensure that there was no spatial variation in luminance within individual noise elements. A new stochastic noise sample was used for each trial. Note that the use of this noise size would not significantly introduce luminance artifacts [39], [40].


Processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia.

Tang Y, Liu C, Liu Z, Hu X, Yu YQ, Zhou Y - PLoS ONE (2014)

Illustration of stimuli used in this experiment.(a) noise carrier, (b) first-order stimulus, (c) second-order stimulus. All stimuli are presented at screen center, subtended 2.51°×2.51°.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4237427&req=5

pone-0113400-g001: Illustration of stimuli used in this experiment.(a) noise carrier, (b) first-order stimulus, (c) second-order stimulus. All stimuli are presented at screen center, subtended 2.51°×2.51°.
Mentions: The noise carrier (Figure 1a) was a 1-bit, spatially 2-d, static noise pattern generated by assigning individual (single) screen pixels (0.025 degree of visual angle) to be either ‘white’ or ‘black’ with equal probability to ensure that there was no spatial variation in luminance within individual noise elements. A new stochastic noise sample was used for each trial. Note that the use of this noise size would not significantly introduce luminance artifacts [39], [40].

Bottom Line: We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies.In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings.These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Brain Function and Diseases, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, People's Republic of China; Research and Treatment Center of Amblyopia and Strabismus, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.

ABSTRACT
Several studies have indicated substantial processing deficits for static second-order stimuli in amblyopia. However, less is known about the perception of second-order moving gratings. To investigate this issue, we measured the contrast sensitivity for second-order (contrast-modulated) moving gratings in seven anisometropic amblyopes and ten normal controls. The measurements were performed with non-equated carriers and a series of equated carriers. For comparison, the sensitivity for first-order motion and static second-order stimuli was also measured. Most of the amblyopic eyes (AEs) showed reduced sensitivity for second-order moving gratings relative to their non-amblyopic eyes (NAEs) and the dominant eyes (CEs) of normal control subjects, even when the detectability of the noise carriers was carefully controlled, suggesting substantial processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia. In contrast, the non-amblyopic eyes of the anisometropic amblyopes were relatively spared. As a group, NAEs showed statistically comparable performance to CEs. We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies. In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings. These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia.

Show MeSH
Related in: MedlinePlus