miun.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Ekström, Johan G.
Alternative names
Publications (2 of 2) Show all publications
Ekström, J. G. & Beaven, C. M. (2014). Effects of blue light and caffeine on mood. Psychopharmacology, 231(18), 3677-3683
Open this publication in new window or tab >>Effects of blue light and caffeine on mood
2014 (English)In: Psychopharmacology, ISSN 0033-3158, E-ISSN 1432-2072, Vol. 231, no 18, p. 3677-3683Article in journal (Refereed) Published
Abstract [en]

Both short wavelength (blue) light and caffeine have been studied for their mood enhancing effects on humans. The ability of blue light to increase alertness, mood and cognitive function via non-image forming neuropathways has been suggested as a non-pharmacological countermeasure for depression across a range of occupational settings. This experimental study compared blue light and caffeine and aimed to test the effects of blue light/placebo (BLU), white light/240-mg caffeine (CAF), blue light/240-mg caffeine (BCAF) and white light/placebo (PLA), on mood. A randomised, controlled, crossover design study was used, in a convenience population of 20 healthy volunteers. The participants rated their mood on the Swedish Core Affect Scales (SCAS) prior to and after each experimental condition to assess the dimensions of valence and activation. There was a significant main effect of light (p = 0.009), and the combination of blue light and caffeine had clear positive effects on core effects (ES, ranging from 0.41 to 1.20) and global mood (ES, 0.61 +/- 0.53). The benefits of the combination of blue light and caffeine should be further investigated across a range of applications due to the observed effects on the dimensions of arousal, valence and pleasant activation.

Keywords
Arousal, Drug potentiation, Phototherapy, Valence
National Category
Sport and Fitness Sciences Psychology
Identifiers
urn:nbn:se:miun:diva-23225 (URN)10.1007/s00213-014-3503-8 (DOI)000341371300002 ()2-s2.0-84906937441 (Scopus ID)
Available from: 2014-10-16 Created: 2014-10-16 Last updated: 2017-12-05Bibliographically approved
Beaven, C. M. & Ekstrom, J. (2013). A Comparison of Blue Light and Caffeine Effects on Cognitive Function and Alertness in Humans. PLoS ONE, 8(10), e76707
Open this publication in new window or tab >>A Comparison of Blue Light and Caffeine Effects on Cognitive Function and Alertness in Humans
2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 10, p. e76707-Article in journal (Refereed) Published
Abstract [en]

The alerting effects of both caffeine and short wavelength (blue) light have been consistently reported. The ability of blue light to enhance alertness and cognitive function via non-image forming neuropathways have been suggested as a non-pharmacological countermeasure for drowsiness across a range of occupational settings. Here we compare and contrast the alerting and psychomotor effects of 240 mg of caffeine and a 1-h dose of similar to 40 lx blue light in a non-athletic population. Twenty-one healthy subjects performed a computer-based psychomotor vigilance test before and after each of four randomly assigned trial conditions performed on different days: white light/placebo; white light/240 mg caffeine; blue light/placebo; blue light/240 mg caffeine. The Karolinska Sleepiness Scale was used to assess subjective measures of alertness. Both the caffeine only and blue light only conditions enhanced accuracy in a visual reaction test requiring a decision and an additive effect was observed with respect to the fastest reaction times. However, in a test of executive function, where a distraction was included, caffeine exerted a negative effect on accuracy. Furthermore, the blue light only condition consistently outperformed caffeine when both congruent and incongruent distractions were presented. The visual reactions in the absence of a decision or distraction were also enhanced in the blue light only condition and this effect was most prominent in the blue-eyed participants. Overall, blue light and caffeine demonstrated distinct effects on aspects of psychomotor function and have the potential to positively influence a range of settings where cognitive function and alertness are important. Specifically, despite the widespread use of caffeine in competitive sporting environments, the possible impact of blue light has received no research attention.

National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:miun:diva-20637 (URN)10.1371/journal.pone.0076707 (DOI)000325501300082 ()2-s2.0-84885077165 (Scopus ID)
Available from: 2013-12-11 Created: 2013-12-11 Last updated: 2017-12-06Bibliographically approved
Organisations

Search in DiVA

Show all publications