Elana Lavine, BSc
As the elderly population becomes an increasingly larger proportion of society, a key focus of scientific research will be the process of normal brain aging. Exactly what processes are considered to be a part of normal aging? Much of the literature examines the pathological changes observed in the brain of patients with such diseases as Alzheimer's and Parkinson's. However, the changes in brain morphology during senescence, as evidenced by studies of the healthy elderly, help shed light on what is truly attributable to aging and what is attributable to disease. The distinction between the two may be blurred by influences of lifestyle, such as diet and exercise. Individual variation in outcome measures, such as short-term memory, may create a wide range of what may be categorized as "normal" function. In addition, there exists a relative absence of neuropathological data from well-characterized healthy aged adults studied over extended periods of time.1
Brain Size & Morphological Change
By 80 years of age, the average brain has decreased 15% in weight, and is noted as having smaller gyri, separated by wider sulci.2 Specific research has focused on finding out exactly which parts of the human brain contribute to the decrease in weight. Supratentorial brain atrophy has been shown to progress with aging, and specifically with a reduction in the volume of gray matter.
