Polymodal analysis of novel association fiber tract in higher-order visual processing

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20735
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0802:Biomedical structure and function and related fields
• Research Institution: Chiba University
• Principal Investigator: Jitsuishi Tatsuya 千葉大学, 大学院医学研究院, 助教 (50963039)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: 神経線維束 / 脳白質解剖 / Tractography

Outline of Final Research Achievements

In this study, we analyzed the structure and function of a novel nerve fiber tracts, IPS-FG, which connects the fusiform gyrus in the posterior temporal lobe and the intraparietal sulcus. In the analysis using MRI, structural connectivity was analyzed by tractography. In addition, we performed functional MRI analysis of the brain at resting state. However, no significant relationship was found between the structural connectivity of the nerve fiber tract IPS-FG.
Therefore, we conducted an analysis of higher-order visual processing tasks (such as working memory and motor task). When analyzing image recognition tasks and motor instruction tasks, activation responses were observed in IPS areas and FG areas.
In addition, structural analysis revealed that the parieto-occipital sulcus (POS), located inside the IPS, also has high structural connectivity with the occipital lobe visual cortex (V1, V2).

Free Research Field

解剖学

Academic Significance and Societal Importance of the Research Achievements

視覚情報は日常生活の様々な場面に大きな役割を果たしているが、高次視覚情報の処理は不明な点が多い。視覚情報は一次視覚野から物体認識の情報は腹側経路へ、空間的情報は背側路へと伝達され処理されると考えられ、本研究の対象となった頭頂間溝IPSは背側経路、紡錘状回FGは腹側経路に位置している。本研究の結果からは、これらをつなぐ神経束が図形認識や運動指示に関連する可能性が示された。
加えて、頭頂間溝IPSの内側に位置する頭頂後頭溝POSも視覚野との構造的結合性があることが示され、これらの結果は、読書や図形認識など高次の視覚に関する基礎的な理解に寄与すると考えられる。