Asymmetries of the planum temporale and Heschl's gyrus: relationship to language lateralization
Bibliographic record
Abstract
Morphological asymmetries favouring the left hemisphere in the planum temporale (PT) and Heschl's gyrus (HG) have both been presumed to relate to the typical left-hemisphere dominance for language functions. However, a direct link between structure and function has not been clearly established. The present study investigates this issue by measuring the volume of the PT and HG on the MRI scans of epilepsy patients classified into three groups: left speech group (LSG; n = 20), right speech group (RSG; n = 11) and bilateral speech group (BSG; n = 13), as assessed by the intracarotid Sodium Amytal procedure. Additionally, an automatic voxel-based morphometry (VBM) analysis was performed to explore collateral structural asymmetries. Although leftward structural asymmetries were found in the PT, consistent with the literature, they did not relate to language lateralization. For HG we also replicated asymmetries favouring the left side; interestingly, three of the individuals within the RSG showed a strongly reversed asymmetry, but as a whole the structure-function relationship for HG was not obligatory. The VBM analysis revealed a grey-matter concentration difference in the posterior part of the inferior frontal gyrus (pars opercularis, corresponding functionally to Broca's area), which favoured the left hemisphere in the LSG, and the right hemisphere in the RSG. The findings suggest that this frontal cortical region bears a direct relationship to language lateralization, which may be related to use-dependent plasticity in patients with language reorganization.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| 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) | 0.002 | 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".