Glucose enhancement of a facial recognition task in young adults

Numerous studies have reported that glucose administration enhances memory processes in both elderly and young adult subjects. Although these studies have utilized a variety of procedures and paradigms, investigations of both young and elderly subjects have typically used verbal tasks (word list rec all, paragraph recall, etc.). In the present study, the effect of glucose c onsumption on a nonverbal, facial recognition task in young adults was exam ined. Lemonade sweetened with either glucose (50 g) or saccharin (23.7 mg) was consumed by college students (mean age of 21.1 years) 15 min prior to a facial recognition task. The task consisted of a familiarization phase in which subjects were presented with "target" faces, followed immediately by a :recognition phase in which subjects had to identify the targets among a random array of familiar target and novel "distractor" faces. Statistical a nalysis indicated that there were no differences on hit rate (target identi fication) for subjects who consumed either saccharin or glucose prior to th e test. However, further analyses revealed that subjects who consumed gluco se committed significantly fewer false alarms and had (marginally) higher d -prime scores (a signal detection measure) compared to subjects who consume d saccharin prior to the lest. These results parallel a previous report dem onstrating glucose enhancement of a facial recognition task in probable Alz heimer's patients; however, this is believed to be the first demonstration of glucose enhancement for a facial recognition task in healthy, young adul ts. (C) 2000 Elsevier Science Inc. All rights reserved.