Choice of Grating Orientation for Evaluation of Peripheral Vision

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jinglescode opened this issue 4 years ago · 0 comments

Paper

evaluate peripheral resolution and detection for different orientations in different visual field meridians

for accurate visual evaluation, 3 factors should be taken into considerations:
- acuity (resolution or detection)
- field loci (enncentricity and meridian)
- stimulus properties (orientation of stimulus)
peripheral resolution acuity is dependent on the orientation of visual stimuli (the meridional effect)
- stimuli oriented radially along a meridian are better resolved
high contract resolution is relatively unaffected by optical errors because it is neurally limited, whereas detection is affected by optical errors
- stimulus with spatial frequency above neural sampling limit cannot be resolved
- undersampled stimulus undergoes aliasing and can be perceived through moire patterns with a low spatial frequency, lower contrast, and different orientation
meridional preference for detection tasks may be a combination of optical and neural orientation sensitivities
sinusoidal gratings are common stimulus choice for research on peripheral vision, suitable for evaluating detection and resolution acuity and contrast sensitivity

acuity is better for gratings oriented along the meridian
sinusoidal gratings's Gaussian window reduce the contrast of the stimuli, at radius of 1 standard deviation, the Gaussian window reduces the contrast, this means that the contrast in the center of the stimulus has been reduced to about 55% at 1 standard deviation away from the center
studies that uses sinusoidal gratings in circular window have reported better detections, caused by well known edge effect
grating parallel to visual field meridian will produce better acuity than perpendicular grating