Normal Aging and the Perception of Curvature Shapes
Bibliographic record
Abstract
PURPOSE: The present study assessed whether different curve geometries involve different perceptual processing levels and whether these perceptual requirements can interact with the normal aging process. METHODS: Amplitude thresholds for three different curve types were assessed for young and older observers using 2AFC psychophysical methods. The stimuli were individually adjusted for visibility. The three stimulus types evaluated represented a bell shape, a quadratic, and a compressed arc function. RESULTS: As predicted, the geometry influenced the perception of curvature where the compressed arc was most difficult to perceive followed by the quadratic and bell-shaped curves. Moreover, older observers showed relatively higher thresholds for the quadratic and compressed arc shapes, while they had similar thresholds to the younger observers for the bell-shaped function. CONCLUSIONS: In general, the data support the notion that aging affects the processing of curvature requiring the integration of oriented receptors. This is in accordance with studies that have found reduced orientation selectivity of cortical neurons in senescent animals. Our findings suggest that older observers would have more difficulties with form discrimination tasks where curvature is an inherent component of the image and also predict age-related differences in perceiving ophthalmic lens-induced distortions.
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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 | 0.003 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| 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".