Cross-orientation masking in the red-green isoluminant and luminance systems
Bibliographic record
Abstract
Purpose: Cross-orientation masking (XOM) is defined psychophysically as the phenomenon whereby detection of a test grating is masked by the presence of a superimposed stimulus at an orthogonal orientation. A previous study found that XOM for achromatic stimuli is strongest at mid-high temporal and low spatial frequencies, the putative M cell range (Meese and Holmes, Proc. R. Soc. B., 274, p127, 2007). Here we investigate whether color vision can support XOM by using red-green isoluminant stimuli, and achromatic stimuli for comparison with the luminance system. Methods: Horizontal Gabor stimuli (Gaussian contrast envelope, σ=2 degrees) were modulated at two spatial (0.375 & 0.75cpd) and two temporal frequencies (2 & 4Hz). An orthogonal vertical Gabor patch with the same spatio-temporal configuration was superimposed (i.e. a plaid). Binocular contrast detection thresholds were determined using a temporal 2AFC staircase method over a wide range of mask contrasts (scaled in multiples of detection threshold). Results: We find three new results for color vision: 1. robust XOM for color vision for the spatio-temporal frequencies tested over a wide range of mask contrasts; 2. greater cross-orientation facilitation at low mask contrasts for chromatic than for achromatic stimuli, and 3. significantly greater masking for the chromatic than the achromatic stimuli when mask contrast is high. Conclusions: Such robust and distinct chromatic masking effects indicate that M cells do not exclusively support cross orientation masking in this spatio-temporal range and suggest differential constraints on chromatic compared to achromatic cross-orientation suppression along the cortical or subcortical streams.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".