P4–240: Practice effects and longitudinal cognitive change in normal aging versus incident mild cognitive impairment and dementia in the Mayo Clinic Study of Aging. (1st July 2013) - Machulda, Mary; Pankratz, Vernon; Christianson, Teresa; Mielke, Michelle; Roberts, Rosebud; Ivnik, Robert; Knopman, David; Boeve, Bradley; Petersen, Ronald