Age-related changes in processing speed: Unique contributions of cerebellar and prefrontal cortex

Age-related declines in processing speed are hypothesized to underlie the widespread changes in cognition experienced by older adults. we used a structural covariance approach to identify putative neural networks that underlie age-related structural changes associated with processing speed for 42 adults ranging in age from 19 to 79 years. to characterize a potential mechanism by which age-related gray matter changes lead to slower processing speed,we examined the extent to which cerebral small vessel disease influenced the association between age-related gray matter changes and processing speed. a frontal pattern of gray matter and white matter variation that was related to cerebral small vessel disease,as well as a cerebellar pattern of gray matter and white matter variation were uniquely related to age-related declines in processing speed. these results demonstrate that at least two distinct factors affect age-related changes in processing speed,which might be slowed by mitigating cerebral small vessel disease and factors affecting declines in cerebellar morphology. © 2010 eckert,keren,roberts,calhoun and harris.