Aaron Smith died on June 13, 1998. He was a past president and founding member of the International Neuropsychological Society, Charter Member and Diplomate of the American Board of Clinical Neuropsychology, Editor of the International Journal of Neuroscience and Professor Emeritus of the University of Michigan. He also developed the Symbol Digit Modalities Test and the Michigan Neuropsychological Battery. In both cases he employed a rationale which permitted differentiation of impairments in higher cognitive functions that the tests were designed to measure from deficits in lower sensory input and motor output modalities which were required to carry out the tests.