The development of sensitivity to first- and second-order pattern versus motion
Bibliographic record
Abstract
We measured sensitivity to first- and second-order pattern and motion in 5-, 7-, and 10-year-old children and in adults. Luminance (FO) and contrast (SO) were modulated over trials to measure the minimum modulation yielding 82% correct responses. We measured thresholds for four different conditions: the discrimination of the orientation (horizontal vs. vertical) of a stationary pattern and the discrimination of direction of motion (left vs. right) for three different combinations of temporal frequency (TF) and velocity (V): TF = 6 Hz, V=6 d/s; TF = 1.5 Hz, V = 6 d/s; TF = 1.5 Hz, V = 1.5 d/s. Adults and children (n=56/age grp) provided individual thresholds for one of the four conditions and for both types of stimuli (FO & SO). At all ages, observers were more sensitive to SO pattern than to SO motion, but showed the opposite for FO stimuli (ps[[lt]]0.001). This suggests that information about pattern is necessary to discriminate the direction of SO but not FO motion, as would be expected if SO motion, but not FO motion, is processed using a feature tracking mechanism (Seiffert & Cavanagh, 1998). For SO stimuli, children achieved adult-like thresholds by 7 years of age for all four conditions. Surprisingly, for FO motion, their thresholds for pattern discrimination were not adult-like until 10 years of age and even at that age, they were still immature at discriminating the direction of motion in one condition: TF =1.5 Hz, V=6 d/s (p[[lt]]0.001). The finding of earlier maturity for some conditions of SO than FO stimuli is consistent with recent findings in monkeys (Kiorpes, Gavlin, & El-Shamayleh, 2006).
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".