Senescent effects on binocular summation for contrast sensitivity and spatial interval acuity
Bibliographic record
Abstract
PURPOSE: Age effects on binocular summation, a cortically mediated visual function, were compared for resolution acuity, contrast sensitivity (CS), and spatial interval (SI) hyperacuity. METHOD: The binocular and monocular thresholds of healthy, optimally-corrected healthy young (mean age 21.3 years) and old (mean age 69.9 years) observers were determined for acuity, SI discrimination, and CS at 1.0, 2.0, 4.0, 8.0 and 18.0 c/deg. RESULTS: No age effects were observed on monocular or binocular SI discrimination. The binocular summation ratios (BSRs) did not exceed the expected probability gain for resolution acuity or SI discrimination in either age group. Older observers showed a binocular inhibition effect on the SI task. On the CS task, the BSRs of the young significantly exceeded those of the old only at 18.0 c/deg. CONCLUSIONS: 1.) Binocular summation of high spatial frequency contrast information, which may be less robust in the senescent visual system, did not appear to be related to interocular CS differences, 2.) SI discrimination of high contrast, well-separated targets appears to be unaffected by aging, and 3.) Binocular neural summation on SI discrimination may be more likely to be seen with targets that are narrowly separated or low in contrast.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".