The Localization and Patterns of Dyschromatopsia in Prosopagnosic Subjects (S48.007)
Bibliographic record
Abstract
OBJECTIVE: To determine if dyschromatopsia in the setting of acquired or developmental prosopagnosia is characterized by selective impairment of specific regions of colour space. BACKGROUND: Previous case reports of central dyschromatopsia do not concur as to which types of cortical lesions are associated with colour vision impairments. DESIGN/METHODS: We investigated hue discrimination in a cohort of 12 subjects with acquired prosopagnosia and 9 with developmental prosopagnosia, along with 42 matched controls, using the Farnsworth-Munsell 100-hue test. RESULTS: We found impaired hue discrimination in 6 subjects with acquired prosopagnosia, 5 with bilateral and one with a unilateral occipitotemporal lesion. Structural MRI analysis showed maximum overlap of lesions in the right and left lingual and fusiform gyri. Fourier analysis of their error scores showed tritanopic-like deficits and blue-green impairments, similar to tendencies displayed by the healthy controls. Three subjects also showed a novel fourth Fourier component, indicating additional deficits in purple and green-yellow regions. No subject with developmental prosopagnosia had impaired hue discrimination. CONCLUSIONS: We conclude that, in subjects with prosopagnosia, dyschromatopsia is limited to those with acquired lesions of the fusiform gyri, usually bilateral but sometimes unilateral. The dyschromatopsic deficit shows an accentuation of normal tritanopic-like tendencies, sometimes accompanied by anomalous deficits that do not correspond to traditional red-green axes. Study Supported by: This work was supported by CIHR operating grant MOP-102567 to JB. JB was supported by a Canada Research Chair and the Marianne Koerner Chair in Brain Diseases. BD was supported by grants from the Economic and Social Research Council (UK) (RES-062-23-2426) and the Hitchcock Foundation. SC was supported by National Eye Institute award F32 EY023479-02. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 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".