The Aging Brain: How Changes in White Matter Impact Perception

Published on March 9, 2023

Imagine a city with multiple neighborhoods connected by highways and streets. As we grow older, the roads in our brain, called white matter fiber tracts, can become less efficient and interconnected. In this study, scientists used advanced imaging techniques to investigate how these changes in the aging brain affect our ability to perceive global motion. By comparing younger and older adults, they found that decreased global motion perception in older adults was linked to reduced integrity in specific regions of white matter fiber tracts. Additionally, they discovered that the efficiency of information flow between distant cortical regions was also diminished in older adults with decreased global motion sensitivity. These findings support the idea that age-related declines in perception may be due to reduced communication within the brain’s network. This research paves the way for future studies on cognitive aging and offers insights into potential strategies for improving perception in older adults. To dive deeper into the details of this exciting research, check out the full article!

Previous studies have mainly explored the effects of structural and functional aging of cortical regions on global motion sensitivity in older adults, but none have explored the structural white matter (WM) substrates underlying the age-related decrease in global motion perception (GMP). In this study, random dot kinematogram and diffusion tensor imaging were used to investigate the effects of age-related reductions in WM fiber integrity and connectivity across various regions on GMP. We recruited 106 younger adults and 94 older adults and utilized both tract-based spatial statistics analysis and graph theoretical analysis to comprehensively investigate group differences in WM microstructural and network connections between older and younger adults at the microscopic and macroscopic levels. Moreover, partial correlation analysis was used to explore the relationship between alterations in WM and the age-related decrease in GMP. The results showed that decreased GMP in older adults was related to decreased fractional anisotropy (FA) of the inferior frontal-occipital fasciculus, inferior longitudinal fasciculus, anterior thalamic radiation, superior longitudinal fasciculus, and cingulum cingulate gyrus. Decreased global efficiency of the WM structural network and increased characteristic path length were closely associated with decreased global motion sensitivity. These results suggest that the reduced GMP in older adults may stem from reduced WM integrity in specific regions of WM fiber tracts as well as decreased efficiency of information integration and communication between distant cortical regions, supporting the “disconnection hypothesis” of cognitive aging.

Read Full Article (External Site)

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>