Premium
Administration of exogenous melatonin increases spreading activation in lexical memory networks
Author(s) -
Foster Paul S.,
Campbell Ransom W.,
Williams Megan R.,
Branch Kaylei K.,
Roosa Katelyn M.,
Orman Caitlin,
Drago Valeria
Publication year - 2014
Publication title -
human psychopharmacology: clinical and experimental
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.461
H-Index - 78
eISSN - 1099-1077
pISSN - 0885-6222
DOI - 10.1002/hup.2416
Subject(s) - melatonin , fluency , psychology , verbal fluency test , recall , association (psychology) , audiology , verbal memory , cognitive psychology , neuropsychology , cognition , developmental psychology , medicine , neuroscience , mathematics education , psychotherapist
Objective Several studies have examined the effect of exogenous melatonin on memory and cognitive functioning. Many of these investigations have reported improvement in recall and recognition as well as performance on various other indices of neuropsychological functioning. However, there have been no investigations reported that have examined the effects of exogenous melatonin administration on spreading activation in lexical and semantic memory networks. Hence, the purpose of this investigation was to determine the effects of melatonin on spreading activation. Methods Participants were randomly assigned to either a 3‐mg or 5‐mg dose group, and spreading activation was measured both before and after administration. Spreading activation was measured by calculating the average word frequencies for words generated on the controlled oral word association test and the semantic fluency test. Results A significant main effect for time was found, with the controlled oral word association test average word frequency being significantly higher at baseline than after taking melatonin. Also, a significant group × time interaction was found when using log transformed data. Multiple comparisons indicated that the 3‐mg group exhibited significantly greater spreading activation following melatonin than the 5‐mg group. The results indicate that melatonin may produce an increase in spreading activation in lexical memory networks. These results potentially provide an explanation for the benefits of melatonin on memory functioning. Copyright © 2014 John Wiley & Sons, Ltd.