The effects of age, glucose ingestion and gluco-regulatory control on episodic memory.
BACKGROUND
Previous research has been inconclusive regarding the impact of glucose ingestion and gluco-regulatory control on cognitive performance in healthy older adults. The aim of this research was to determine whether glucose specifically enhanced episodic memory in an older population. In addition, the link between individual differences in glucose regulation and the magnitude of the enhancement effect was examined.


METHODS
A within subjects, counterbalanced, crossover design was used with 20 participants (60-80 year olds), each serving as his/her control.


METHODS
Episodic memory was tested by presenting unrelated paired associates followed by immediate and delayed cued recall, and delayed recognition, under single and dual task conditions. In addition, a battery of cognitive tests was administered, including tests of semantic memory, working memory and speed of processing.


RESULTS
Glucose ingestion was found to largely facilitate performance of episodic memory. Furthermore, subsidiary analyses found that gluco-regulatory efficiency predicted episodic memory performance in both control and glucose conditions.


CONCLUSIONS
A boost in performance after glucose ingestion was particularly seen in the episodic memory domain. Notably, strong evidence was provided for the utility of gluco-regulatory control measures as indicators of cognitive decline in the elderly.
Riby
Leigh Martin
LM
Department of Psychology, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA, UK. L.Riby@gcal.ac.uk
Meikle
Andrew
A
Glover
Cheryl
C
D000368:Aged; D001143:Arousal / Q000187:drug effects; D001288:Attention / Q000187:drug effects; D001786:Blood Glucose / Q000378:metabolism*; D003118:Color Perception / Q000187:drug effects; D018592:Cross-Over Studies; D004193:Discrimination Learning / Q000187:drug effects; D005260:Female; D005950:Glucose Solution, Hypertonic / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000187:drug effects* / Q000502:physiology; D010153:Paired-Associate Learning / Q000187:drug effects*; D012153:Retention, Psychology / Q000187:drug effects; D012439:Saccharin / Q000008:administration & dosage
D001786:Blood Glucose; D005950:Glucose Solution, Hypertonic; D012439:Saccharin