Reduced frontal white matter microstructure in healthy older adults with low tactile recognition performance

Aging leads to a reduction of connectivity in large-scale structural brain networks. Sensory processing and other cognitive processes rely on information flow between distant brain areas. However, data linking age-related structural brain alterations to cognitive functioning, especially sensory processing, is sparse.\n\nAiming to determine group differences in sensory processing between older and younger participants, we implemented a complex tactile recognition task and investigated to what extent changes in microstructural white matter integrity of large-scale brain networks might reflect success in task performance. Structural brain integrity was accessed by means of diffusion-weighted imaging and fractional anisotrophy.\n\nThe data revealed that poor performance in complex tactile recognition in older, neurologically healthy individuals is related to decreased structural integrity pronounced in the anterior corpus callosum. This region was strongly connected to the prefrontal cortex. Our data suggests decreased fractional anisotrophy in the anterior corpus callosum as a surrogate marker for progressed brain aging, leading to disturbances in networks relevant for higher-order cognitive processing. Complex tactile recognition might be a sensitive marker for identifying these starting cognitive impairments in older adults.