THE EFFECTS OF GLUCOSE ON NONMEMORY COGNITIVE-FUNCTIONING IN THE ELDERLY

The present study evaluated the role of glucose in the performance of a series of memory and nonmemory neuropsychological tasks. Each of the 28 healthy (no evidence of diabetic or dementing disease), elderly (m ean age = 73), subjects participating in the study were tested under e ach of two conditions (50 g glucose or 27.3 mg saccharin) in a counter balanced fashion. While actively manipulating glucose levels in partic ipants, blood glucose (BG) levels were monitored to evaluate the effec tiveness of individual subject's regulation of ingested glucose. It wa s hypothesized that glucose would enhance performance on a memory meas ure (Rey/Taylor Figure) as well as other nonmemory measures (e.g. desi gn fluency, trail making test, etc.). A repeated measures, counterbala nced design was used to evaluate the direct manipulation of glycemic c ondition. Results reveal an enhancement effect on both the recall of t he Rey/Taylor Figure as well as verbal fluency and figural fluency. A significant correlation between glycemic regulation and performance on a test of divided attention (dichotic listening) was also evident (r = -0.47). These findings suggest that a specific facilitation of retri eval mechanisms may account for enhancement of both memory and fluency performance.