Developmental amnesia and its relationship to degree of hippocampal atrophy
Bibliographic record
Abstract
Two groups of adolescents, one born preterm and one with a diagnosis of developmental amnesia, were compared with age-matched normal controls on measures of hippocampal volume and memory function. Relative to control values, the preterm group values showed a mean bilateral reduction in hippocampal volume of 8-9% (ranging to 23%), whereas the developmental amnesic group values showed a reduction of 40% (ranging from 27% to 56%). Despite equivalent IQ and immediate memory scores in the two study groups, there were marked differences between them on a wide variety of verbal and visual delayed memory tasks. Consistent with their diagnosis, the developmental amnesic group was impaired relative to both other groups on nearly all delayed memory measures. The preterm group, by contrast, was significantly impaired relative to the controls on only a few memory measures, i.e., route following and prospective memory. We suggest that early hippocampal pathology leads to the disabling memory impairments associated with developmental amnesia when the volume of this structure is reduced below normal by approximately 20-30% on each side. Whether this is a sufficient condition for the disorder or whether abnormality in other brain regions is also necessary remains to be determined.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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) | 0.000 | 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".