“…By influencing the transmission of neural signals between brain regions, white matter deterioration is likely to affect computation efficiency of neural networks. The application of combined imaging methods to assess white matter, cortical volume, metabolic measures and brain activation is proving to be increasingly important for characterizing the neural bases for age-related cognitive decline as well as variability among older individuals who are the same chronological age (e.g., Daselaar, Iyengar, Davis, Eklund, Hayes, & Cabeza, 2015;Toledo et al, 2015;Zahodne, Manly, Brickman, Siedlecki, DeCarli, & Stern, 2015;Zhu, Johnson, Kim and Gold, 2015). However, linking specific neural indices to specific aspects of cognitive decline continues to be a major challenge (e.g., Salthouse, 2011).…”