Over the past several years we have collaborated with several individuals to study normal aging. Using Alzheimer’s disease, amnesic mild cognitive impairment and healthy individuals we have demonstrated that interhemispheric coupling may be regarded as a flexible mechanism that can improve the brain’s ability to meet processing demands for high cognitive demand in normal aging and for low cognitive demand in AD .
In a recent study the links between cognitive ability and cortical tissue volume in old age were investigated. Evidence from this research warns against an exclusive reliance on the causal link between cognitive function and the cortical tissue in old age based on assumptions of the aging process. Preservation of cortical tissue thickness in old age is not a foundation for successful cognitive aging, but rather reflects a lifelong association .
 J. Ansado, D.L. Collins, S. Joubert, V.S. Fonov, O. Monchi, S.M. Brambati, F. Tomaiuolo, M. Petrides, S. Faure, Y. Joanette, Yves. “Interhemispheric coupling improves the brain’s ability to perform low cognitive demand tasks in Alzheimer’s disease and high cognitive demand tasks in normal aging”, Neuropsychology, Vol 27(4), Jul 2013, 464–480.
 Karama S, Bastin ME, Murray C, Royle NA, Penke L, Muñoz Maniega S, Gow AJ, Corley J, Valdés Hernández Mdel C, Lewis JD, Rousseau MÉ, Lepage C, Fonov V, Collins DL, Booth T, Rioux P, Sherif T, Adalat R, Starr JM, Evans AC, Wardlaw JM, Deary IJ. Childhood cognitive ability accounts for associations between cognitive ability and brain cortical thickness in old age. Mol Psychiatry. 2014 May;19(5):555–9.