Connectomics in aging and cognition

Substantial numbers of imaging studies have been performed with older adults to better understand the brain changes which occur in aging, the neural correlates of age-related cognitive change, and to develop tools that will allow for earlier detection and better understanding of age-related neurodegenerative diseases. In this chapter, we will review general observations about the aging brain that have been determined using a variety of imaging methods, including volumetric imaging, diffusion-weighted magnetic resonance imaging (MRI), resting-state functional MRI, and imaging with positron emission tomography. In addition to highlighting key insights provided by conventional approaches to brain imaging and analysis, we will examine the insights provided by connectomic-style analyses. Focusing largely on healthy aging, we will also examine how neuroimaging measures of brain aging have been linked with cognitive performance. Caveats and future directions in the study of brain aging are discussed.