This increase in the elderly population and the high incidence of age-related neurological disorders make it important to understand how the human brain ages. To investigate the changes that the brain undergoes during aging, neuroscientists use brain imaging methods to observe the anatomy and physiology of the living brain.
Scientists can also study autopsy specimens to investigate how the brain changes over time.
Data from Malmgren, R., in Textbook of Geriatric Neuropsychiatry , 2000. It is thought that this enlargement occurs because cells surrounding the ventricles are lost. Reductions in the size of many areas of the cerebral cortex have been reported. Therefore, many elderly individuals have trouble focusing their eyes. Exposure to ultraviolet light can also yellow the lens.