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Updated: Jul 24, 2026
08:05
Testing Tactile Masking between the Forearms
Published on: February 10, 2016
Comparing contrast-modulated and luminance-modulated masking: effects of spatial frequency and phase
A Willis1, H S Smallman, J M Harris
1Department of Psychology, University of Newcastle, Newcastle upon Tyne, UK. a.willis@napier.ac.uk
Perception
|May 23, 2000
Summary
Contrast-modulated (CM) gratings do not mask visual stimuli solely through distortion products. Masking effects differ significantly between CM and luminance-modulated (LM) gratings, particularly regarding phase dependency.
Area of Science:
- Visual Perception
- Neuroscience
- Image Processing
Background:
- Masking of visual stimuli by gratings can arise from nonlinear transformations.
- Contrast-modulated (CM) gratings might induce masking via distortion products.
Purpose of the Study:
- To investigate whether CM gratings mask visual stimuli through distortion products.
- To compare masking effects of CM gratings with luminance-modulated (LM) gratings.
Main Methods:
- Compared masking by 1 cycle deg-1 CM gratings (simple beats and amplitude-modulated) with 1 cycle deg-1 LM gratings of low contrast.
- Analyzed spatial-frequency tuning functions and phase dependency of masking.
Main Results:
- CM and low-contrast LM grating masks showed similar spatial-frequency tuning around 1 cycle deg-1.
- Low-contrast LM gratings exhibited phase-dependent masking, unlike CM gratings.
Conclusions:
- Masking by CM gratings is not solely explained by distortion products at the modulation frequency.
- Visual masking mechanisms differ between CM and LM gratings, particularly concerning phase sensitivity.
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