HEALTHY AGING, BRAIN STRUCTURES AND NEUROPSYCHOLOGICAL FUNCTIONING

The purpose of this project was to examine some of the interrelationships between the physiology and neuropsychology of healthy aging. Another purpose was to establish a normative base in a healthy elderly group on the Luria-Nebraska Neuropsychological Battery, CT scan and regional cerebral blood flow studies. Few aging studies in the past have employed healthy elderly subjects in their samples. By using a healthy group, it was hoped to examine the effects of age rather than the cumulative effects of trauma, poor lifestyle and health on the central nervous system. In the present study 62 healthy elderly adults were given the Luria-Nebraska Neuropsychological Battery (mean age = 71.1 years, SD = 6.6). Thirty of these volunteers were also given CT scans. Forty-two of these subjects were given regional cerebral blood flow studies. The Luria-Nebraska Battery was found to be a valid measure of neuropsychological functioning in the healthy elderly. The Luria-Nebraska Battery labelled 94% of the elderly as normal. Although the Luria-Nebraska Battery did not label healthy elderly adults as brain damaged is not to say that there were no age effects on this test battery. When compared to an educationally matched young adult group (mean age = 28.0 years) the elderly performed significantly poorer on 11 of the 14 clinical scales. The elderly\u27s scores were from 0.6-1.8 standard deviations more elevated than the young adult scores. This study also found age-related decrements in CT scan and regional cerebral blood flow measurements. The elderly exhibited significant increases in the mean ventricular-brain ratio when compared to young medical controls. Likewise, the elderly exhibited decreases in measures of brain density and regional cerebral blood flow when compared to young adults. The brain-density and regional cerebral blood flow were respectively, 0.6-0.8 standard deviations and 0.6-1.2 standard deviations lower for the elderly. Few one-to-one relationships were seen between the radiological and neuropsychological measures. Several methodological problems of this study are discussed, as are possible explanations for findings using Luria\u27s (1966, 1973) notion of functional systems