Confounds in Separating Effects of Normal Aging from Healthy Successful Aging
Many neuroimaging studies of age-related memory decline interpret resultant differences in brain activation patterns in the elderly as reflecting a type of compensatory response or regression to a simpler state of brain organization. Here I will review a series of our own MEG studies which lead us to an alternative interpretation, and highlights a couple of potential confounds in the aging literature that may act to increase the variability of results within age groups and across laboratories. From our perspective, level of cognitive functioning achieved by a group of elderly is largely determined by the health of individuals within this group. Individuals with a history of hypertension, for example, are likely to have multiple white matter insults which compromise cognitive functioning, independent of aging processes per se. The health of the elderly group has not been well-documented in most previous studies and elderly participants are rarely excluded, or placed into a separate group, due to health-related problems. In addition, recent results show that white matter tracts within the frontal and temporal lobes, regions critical for higher cognitive functions, continue to mature well into the 4th decade of life. This suggests that a young age group may not be the best control group for understanding aging effects on the brain since development is ongoing within this age range. Our goal is to understand normal development across lifespan as well as effects of pathology on cognitive functioning in the aging brain. Download MP4 file of talk here (right click and select "Save Link As..." or equivalent to download).
Dr. Cheryl Aine is a Research Professor in the Department of Radiology, School of Medicine at the University of New Mexico. She has been mostly engaged in the advancement of magnetoencephalography (MEG) methods (e.g., use of computer simulations to test algorithmic performance), basic visual research and clinical research in aging, Alzheimer’s disease, and schizophrenia, using various noninvasive imaging methods. She has served as the Deputy Group Leader of the Biophysics Group at Los Alamos National Laboratory, Scientific Director of the Center for Functional Brain Imaging at the VA Medical Center in Albuquerque, Chief of the Division of Biophysics in the Department of Radiology at UNM, and Director of the MEG Division of the MIND Institute. She received her Ph.D. in Experimental Psychology from the University of North Carolina at Greensboro in 1983.