Abnormal cortical activation in response to motion in people who have lost one eye early in life
Bibliographic record
Abstract
Early monocular visual deprivation such as amblyopia is associated with deficits in the perception of motion as well as spatial vision and a decrease in cortical activation in response to motion (Bonhomme et al., 2006). Early unilateral enucleation (removal of an eye), however, results in deficits in the perception of motion but not spatial vision. This latter patient group provides a valuable model to examine the effects of a loss of binocularity on visual motion processing without the potential confound of poor spatial visual ability. We compared cortical activation for motion in early enucleated patients compared to controls using fMRI. Participants: To date, we have tested two adult patients with unilateral eye enucleation before the age of two years and three binocularly intact controls viewing monocularly and binocularly. Methods: Stimuli consisted of white random dot patterns on a black background within a circular aperture. Using a block design motion localizer, stimuli alternated in time between 16 seconds of motion (linear motion in eight different directions, changing direction every second) and 16 seconds of stationary dots. Results: Talairach coordinates for area MT in the one eyed patients are consistent with those of the controls. Preliminary results indicate a greater extent of activation in response to motion in the patients compared to controls in area MT ipsilateral to the remaining eye. The patient with the earliest age at enucleation also shows morphological differences such that early visual areas in the hemisphere ipsilateral to the remaining eye are larger compared to the opposite hemisphere. Conclusions: Unlike deprivation from amblyopia and despite previous behavioural findings for deficits in motion perception with early enucleation, our patients show more activation in response to motion. These findings suggest that early unilateral enucleation results in unique cortical reorganization at both an anatomical and functional level.
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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 | 0.000 |
| 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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".