TY - JOUR

T1 - Investigation into the significance of task difficulty and divided allocation of resources on the glucose memory facilitation effect.

AU - Sünram-Lea, Sandra I.

AU - Foster, Jonathan K.

AU - Durlach, Paula

AU - Perez, Catalina

PY - 2002/4

Y1 - 2002/4

N2 - Rationale: Memory for a list of 20 words can be enhanced by preceding learning with consumption of 25 g glucose rather than an equally sweet aspartame solution. In previous studies, participants performed a secondary hand-movement task during the list-learning phase. Objective: The present placebo-controlled, double-blind study examined whether the additional cognitive load created by a secondary task is a crucial feature of the glucose memory facilitation effect. Methods: The effect of glucose administration on word recall performance in healthy young participants was examined under conditions where the primary memory task and a secondary task were competing for cognitive resources (across a range of secondary tasks), and where task difficulty was increased but dual task-mediated competition for cognitive resources did not exist. Measures of non-verbal and working memory performance were also compared under the different glycaemic conditions (glucose versus aspartame drinks). Results: In the present study, a beneficial effect of glucose on memory was detected after participants encoded a 20-word list while performing a secondary task, but not when participants encoded the list without a secondary task, nor when the 20 target words were intermixed with 20 non-target words (distinguished by gender of speaker). In addition, glucose significantly enhanced performance on spatial and working memory tasks. Conclusion: The data indicate that possible "depletion" of episodic memory capacity and/or glucose-mediated resources in the brain due to performing a concomitant cognitive task might be crucial to the demonstration of a glucose facilitation effect. Possible implications regarding underlying cognitive and physiological mechanisms are discussed in this article.

AB - Rationale: Memory for a list of 20 words can be enhanced by preceding learning with consumption of 25 g glucose rather than an equally sweet aspartame solution. In previous studies, participants performed a secondary hand-movement task during the list-learning phase. Objective: The present placebo-controlled, double-blind study examined whether the additional cognitive load created by a secondary task is a crucial feature of the glucose memory facilitation effect. Methods: The effect of glucose administration on word recall performance in healthy young participants was examined under conditions where the primary memory task and a secondary task were competing for cognitive resources (across a range of secondary tasks), and where task difficulty was increased but dual task-mediated competition for cognitive resources did not exist. Measures of non-verbal and working memory performance were also compared under the different glycaemic conditions (glucose versus aspartame drinks). Results: In the present study, a beneficial effect of glucose on memory was detected after participants encoded a 20-word list while performing a secondary task, but not when participants encoded the list without a secondary task, nor when the 20 target words were intermixed with 20 non-target words (distinguished by gender of speaker). In addition, glucose significantly enhanced performance on spatial and working memory tasks. Conclusion: The data indicate that possible "depletion" of episodic memory capacity and/or glucose-mediated resources in the brain due to performing a concomitant cognitive task might be crucial to the demonstration of a glucose facilitation effect. Possible implications regarding underlying cognitive and physiological mechanisms are discussed in this article.

KW - Glucose Short-term memory Long-term memory Task difficulty

U2 - 10.1007/s00213-001-0987-9

DO - 10.1007/s00213-001-0987-9

M3 - Journal article

VL - 160

SP - 387

EP - 397

JO - Psychopharmacology

JF - Psychopharmacology

SN - 1432-2072

IS - 4

ER -