Functional Magnetic Resonance Imaging of Compensatory Neural Recruitment in Aging and Risk for Alzheimer's Disease: Review and Recommendations

There has been a recent proliferation of functional magnetic resonance imaging ( fMRI) studies that interpret between-group or within-group differences in brain response patterns as evidence for compensatory neural recruitment. However, it is currently a challenge to determine whether these observed differences are truly attributable to compensatory neural recruitment or whether they are indicative of some other cognitive or physiological process. Therefore, the need for a standardized set of criteria for interpreting whether differences in brain response patterns are compensatory in nature is great. Focusing on studies of aging and potentially prodromal Alzheimer's disease conditions ( genetic risk, mild cognitive impairment), we critically review the functional neuroimaging literature purporting evidence for compensatory neural recruitment. Finally, we end with a comprehensive model set of criteria for ascertaining ported. This proposed model addresses significant brain region, activation pattern, and behavioral performance considerations, and is therefore termed the Region-Activation-Performance model (RAP model). Copyright (c) 2008 S. Karger AG, Basel