title: Exposure to Blue Light Increases Subsequent Functional Activation of the Prefrontal Cortex During Performance of a Working Memory Task.
abstract: Prolonged exposure to blue wavelength light has been shown to have an alerting effect, and enhances performance on cognitive tasks. A small number of studies have also shown that relatively short exposure to blue light leads to changes in functional brain responses during the period of exposure. The extent to which blue light continues to affect brain functioning during a cognitively challenging task after cessation of longer periods of exposure (i.e., roughly 30 minutes or longer), however, has not been fully investigated.
  
  
  
  A total of 35 healthy participants (18 female) were exposed to either blue (469 nm) (n = 17) or amber (578 nm) (n = 18) wavelength light for 30 minutes in a darkened room, followed immediately by functional magnetic resonance imaging (fMRI) while undergoing a working memory task (N-back task).
  
  
  
  Participants in the blue light condition were faster in their responses on the N-back task and showed increased activation in the dorsolateral (DLPFC) and ventrolateral (VLPFC) prefrontal cortex compared to those in the amber control light condition. Furthermore, greater activation within the VLPFC was correlated with faster N-back response times.
  
  
  
  This is the first study to suggest that a relatively brief, single exposure to blue light has a subsequent beneficial effect on working memory performance, even after cessation of exposure, and leads to temporarily persisting functional brain changes within prefrontal brain regions associated with executive functions. These findings may have broader implication for using blue-enriched light in a variety of work settings where alertness and quick decision-making are important.
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: Anna
authors.initials: A
authors.lastname: Alkozei
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: Ryan
authors.initials: R
authors.lastname: Smith
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: Derek A
authors.initials: DA
authors.lastname: Pisner
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: John R
authors.initials: JR
authors.lastname: Vanuk
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Berryhill
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: Andrew
authors.initials: A
authors.lastname: Fridman
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: Bradley R
authors.initials: BR
authors.lastname: Shane
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.
authors.forename: Sara A
authors.initials: SA
authors.lastname: Knight
authors.affiliation: Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, AZ.|McLean Hospital, Harvard Medical School, Belmont, MA.
authors.forename: William D S
authors.initials: WD
authors.lastname: Killgore
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008027:Light; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: N-back task; PFC; amber light; blue light; fMRI; functional magnetic resonance imaging; prefrontal cortex; working memory