Oregon Brain Aging Study

Oregon Brain Aging Study

The Oregon Brain Aging Study (OBAS) was initiated in 1989 and recruited 293 community- dwelling men and women aged 65 years and older who were generally free of usual confounding factors known to modify risk for cognitive decline (i.e., vascular disease, hypertension, diabetes) to permit a purer study of aging effects on brain parameters.

Individuals invited to participate in the study were age 55 or older, exceptionally healthy, and living in the community. In 2004, a second arm of the study was added. This group was of more average health, and subjects were all age 85 or older at entry. Subjects were recruited through retirement facilities, senior fairs, flyers and word of mouth in the community.

During the Study

Subjects are contacted every six months and are seen annually for their lifetime. During annual study visits, subjects receive a battery of neurological and neuropsychological tests, tests of mental functioning such as concentration, memory, and problem-solving skills, a magnetic resonance imaging (MRI) scan of the brain, and tests of balance.

Relation between brain function and structure

As part of the project we ultimately hope to examine brain tissue after death to determine the relation between brain function and structure of healthy elderly individuals. The majority of our study participants are committed to donating their brains for further research. While the study continues today, it is no longer enrolling new subjects.


OBAS has resulted in over 70 peer-reviewed publications to date. Recent publications have focused on nutrient biomarker patterns, gait speed, white matter changes in the brain, and Alzheimer’s disease pathology. Some of the most recent publications include:

Bowman, G.L., Silbert, L.C., Howieson, D., Dodge, H.H., Traber, M.G., Frei, B., Kaye, J.A., Shannon, J., Quinn, J.F. Nutrient biomarker patterns, cognitive function, and MRI measures of brain aging. Neurology, 78, 1-9, 2012.

Sonnen, J.A., Santa Crua, K., Hemmy, L.S., Woltjer, R., Leverenz, J.B., Montine, K.S., Jack, C.R., Kaye, J., Lim, K., Larson, E.B., White, L. Montine, T.J.  Ecology of the aging human brain. Archives of Neurology, 68(8), 1049-56, 2011.

Buracchio, T., Dodge, H., Howieson, D., Wasserman, D., Kaye, J. The trajectory of gait speed preceding MCI. Archives of Neurology. 2010;67(8):980-6. PMCID: NIHMS

Silbert L, Howieson D, Dodge H, Kaye J.  Cognitive impairment risk: White matter hyperintensity progression matters. Neurology, 73 (2): 120-125, 2009. PMCID:  PMC2713187    #207118

Erten-Lyons D, Woltjer R, Dodge H, Nixon R, Vorobik R, Calvert J, Leahy M, Montine T, Kaye J. Factors associated with resistance to dementia despite high Alzheimer's disease pathology. Neurology, 72 (4): 354-360, 2009. PMCID: PMC275065

Carlson NE, Moore MM, Dame A, Howieson D, Silbert LC, Quinn JF, Kaye JA.  Trajectories of brain loss in aging and the development of cognitive impairment. Neurology, 70:828-833, 2008.

Wilmot B, McWeeney SK, Nixon R, Montine T, Laut J, Harrington C, Kaye J. Translational gene mapping of cognitive decline. Neurobiology of Aging, 29(4):524-541, 2008. PMCID:  PMC2684335