Cascade process mediated by left hippocampus and left superior frontal gyrus affects relationship between aging and cognitive dysfunction

Background Cognitive function declines with age and has been shown to be associated with atrophy in some brain regions, including the prefrontal cortex. However, the details of the relationship between aging and cognitive dysfunction are not well understood. Methods Across a wide range of ages (24- to 85-years-old), this research measured the gray matter volume of structural magnetic resonance imaging data in 39 participants, while some brain regions were set as mediator variables to assess the cascade process between aging and cognitive dysfunction in a path analysis. Results Path analysis showed that age affected the left hippocampus, thereby directly affecting the left superior frontal gyrus. Furthermore, the gyrus directly affected higher order flexibility and maintenance abilities calculated as in the Wisconsin card sorting test, and the two abilities affected the assessment of general cognitive function. Conclusion Our finding suggests that a cascade process mediated by the left hippocampus and left superior frontal gyrus is involved in the relationship between aging and cognitive dysfunction.