Morphology of parietal sulci: Intraparietal sulcus, anterior intermediate parietal sulcus of Jensen, and postcentral sulcus with its relation to somatic sensory representations
Notice bibliographique
Résumé
A comprehensive study of the functional organization of the parietal cortex in the human brain requires a clear understanding of the sulcal-gyral morphology and its variability in individual cerebral hemispheres. In the studies presented in this thesis, the Magnetic Resonance Imaging (MRI) technique is used to advance our knowledge of the morphology of several main parietal sulci, namely the postcentral sulcus, the transverse postcentral sulcus, the intraparietal sulcus, and the anterior intermediate parietal sulcus of Jensen (the sulcus of Jensen) by studying the sulci along their entire course in three planes of section: coronal, horizontal and sagittal. This approach provides critical information concerning the association between the end-points of the neighbouring sulci from the surface of the brain to the fundus and subdivision of the major sulci into basic anatomical units for the study of cortical folding patterns.The first study of this thesis is a morphological examination of the region of the anterior parietal lobe in a large sample of MRI brain scans. The anterior parietal lobe is composed of the somatosensory cortex on the postcentral gyrus and it is bounded posteriorly by the postcentral sulcus. The results demonstrate that the postcentral sulcus is a complex of distinct segments, which extend from the medial edge of the hemisphere to the lateral fissure. In certain hemispheres, the postcentral sulcus merges with a prominent sulcus of the posterior parietal lobe, the intraparietal sulcus, on the surface of the brain, but the sulci are always separated by a small gyral passage in the depth. Another sulcus, the transverse postcentral sulcus, extends in parallel with the postcentral sulcus on the ventral part of the postcentral gyrus. The transverse postcentral sulcus may be considered an inferior part of the postcentral sulcal complex because its presence in the brain coincides with an overall shorter length of the postcentral sulcus and, in some cases, it overlaps with the ventral end of the postcentral sulcus.The second study examines the intraparietal sulcus and a sulcus closely associated with it, namely the sulcus of Jensen in many MRI brain volumes. The cortex of the intraparietal sulcus is implicated consistently in studies of visual-motor coordinate transformations, visual-spatial attention, and visual guidance of movement in space. The findings demonstrate that, most frequently, the intraparietal sulcus may be divided into two branches, the anterior and posterior rami, by a gyral bridge, submerged or visible from the surface of the brain. The sulcus of Jensen is located close to this gyral bridge between the two rami of the intraparietal sulcus and it forms a number of patterns with the intraparietal sulcus, most frequently occurring as a side-branch of the intraparietal sulcus or a shallow sulcus associated with it. Commonly, the ventral termination of the sulcus of Jensen is located between the first and second caudal branches of the superior temporal sulcus, which terminate in the inferior parietal lobe, but in a small number of hemispheres it may merge superficially with the first caudal branch of the superior temporal sulcus.The third study applies the morphological findings from the first study to demonstrate a relationship between the structure of the postcentral sulcus and the sensorimotor representations of different body parts in the anterior parietal lobe. The findings demonstrated that the posterior border of the sensorimotor representation of a specific body part was formed by a specific segment of the postcentral sulcus. In addition, the transverse postcentral sulcus functionally related to the sensorimotor representations of the mouth and tongue on the postcentral gyrus in the hemispheres in which it was present. Thus, the morphology of the anterior parietal lobe relates strongly to the functional sensorimotor activation patterns.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».