1
|
Bjerrum LB, Nordhus IH, Sørensen L, Wulff K, Bjorvatn B, Flo-Groeneboom E, Visted E. Acute effects of light during daytime on central aspects of attention and affect: A systematic review. Biol Psychol 2024; 192:108845. [PMID: 38981576 DOI: 10.1016/j.biopsycho.2024.108845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 06/29/2024] [Accepted: 07/02/2024] [Indexed: 07/11/2024]
Abstract
Light regulates both image- and various non-image forming responses in humans, including acute effects on attention and affect. To advance the understanding of light's immediate effects, this systematic review describes the acute effects of monochromatic/narrow bandwidth and polychromatic white light during daytime on distinct aspects of attention (alertness, sustained attention, working memory, attentional control and flexibility), and measures of affect (self-report measures, performance-based tests, psychophysiological measures) in healthy, adult human subjects. Original, peer-reviewed (quasi-) experimental studies published between 2000 and May 2024 were included according to predefined inclusion and exclusion criteria. Study quality was assessed, and results were synthesized across aspects of attention and affect and grouped according to light interventions; monochromatic/narrowband-width or polychromatic white light (regular white, bright white, and white with high correlated color temperature (CCT)). Results from included studies (n = 62) showed that alertness and working memory were most affected by light. Electroencephalographic markers of alertness improved the most with exposure to narrow bandwidth long-wavelength light, regular white, and white light with high CCT. Self-reported alertness and measures of working memory improved the most with bright white light. Results from studies testing the acute effects on sustained attention and attentional control and flexibility were inconclusive. Performance-based and psychophysiological measures of affect were only influenced by narrow bandwidth long-wavelength light. Polychromatic white light exerted mixed effects on self-reported affect. Studies were strongly heterogeneous in terms of light stimuli characteristics and reporting of light stimuli and control of variables influencing light's acute effects.
Collapse
Affiliation(s)
| | | | - Lin Sørensen
- Department of Biological and Medical Psychology, University of Bergen, Norway
| | - Katharina Wulff
- Department of Molecular Biology, Umeå University, Sweden; Wallenberg Centre for Molecular Medicine, Umeå University, Sweden
| | - Bjørn Bjorvatn
- Department of Global Public Health and Primary Care, University of Bergen, Norway; Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Norway
| | | | - Endre Visted
- Department of Clinical Psychology, University of Bergen, Norway
| |
Collapse
|
2
|
Haghani M, Abbasi S, Abdoli L, Shams SF, Baha'addini Baigy Zarandi BF, Shokrpour N, Jahromizadeh A, Mortazavi SA, Mortazavi SMJ. Blue Light and Digital Screens Revisited: A New Look at Blue Light from the Vision Quality, Circadian Rhythm and Cognitive Functions Perspective. J Biomed Phys Eng 2024; 14:213-228. [PMID: 39027713 PMCID: PMC11252550 DOI: 10.31661/jbpe.v0i0.2106-1355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/29/2021] [Indexed: 07/20/2024]
Abstract
Research conducted over the years has established that artificial light at night (ALAN), particularly short wavelengths in the blue region (~400-500 nm), can disrupt the circadian rhythm, cause sleep disturbances, and lead to metabolic dysregulation. With the increasing number of people spending considerable amounts of time at home or work staring at digital screens such as smartphones, tablets, and laptops, the negative impacts of blue light are becoming more apparent. While blue wavelengths during the day can enhance attention and reaction times, they are disruptive at night and are associated with a wide range of health problems such as poor sleep quality, mental health problems, and increased risk of some cancers. The growing global concern over the detrimental effects of ALAN on human health is supported by epidemiological and experimental studies, which suggest that exposure to ALAN is associated with disorders like type 2 diabetes, obesity, and increased risk of breast and prostate cancer. Moreover, several studies have reported a connection between ALAN, night-shift work, reduced cognitive performance, and a higher likelihood of human errors. The purpose of this paper is to review the biological impacts of blue light exposure on human cognitive functions and vision quality. Additionally, studies indicating a potential link between exposure to blue light from digital screens and increased risk of breast cancer are also reviewed. However, more research is needed to fully comprehend the relationship between blue light exposure and adverse health effects, such as the risk of breast cancer.
Collapse
Affiliation(s)
- Masoud Haghani
- Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Samaneh Abbasi
- Department of Medical Physics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Leila Abdoli
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyedeh Fatemeh Shams
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Nasrin Shokrpour
- School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Atefeh Jahromizadeh
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Seyed Mohammad Javad Mortazavi
- Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| |
Collapse
|
3
|
Zohdi H, Märki J, Scholkmann F, Wolf U. Cerebral, systemic physiological and behavioral responses to colored light exposure during a cognitive task: A SPA-fNIRS study. Behav Brain Res 2024; 462:114884. [PMID: 38296201 DOI: 10.1016/j.bbr.2024.114884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/10/2024]
Abstract
Colored light has important implications for human health and well-being, as well as for the aesthetics and function of various environments. In addition to its effects on visual function, colored light has significant effects on cognitive performance, behavior and systemic physiology. The aim of the current study was to comprehensively investigate how colored light exposure (CLE) combined with a cognitive task (2-back) affects performance, cerebral hemodynamics, oxygenation, and systemic physiology as assessed by systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS). 36 healthy subjects (22 female, 14 male, age 26.3 ± 5.7 years) were measured twice on two different days. They were exposed to the sequence of blue and red light or vice versa in a randomized crossover design. During the CLE, the subjects were asked to perform a 2-back task. The 2-back task performance was correlated with changes in the concentration of oxygenated hemoglobin in the prefrontal cortex (red: r = -0.37, p = 0.001; blue: r = -0.33, p = 0.004) and the high-frequency component of the heart rate variability (red: r = 0.35, p = 0.003; blue: r = 0.25, p = 0.04). These changes were independent of the CLE. Sequence-dependent effects were observed for fNIRS signals at the visual cortex (VC) and for electrodermal activity (EDA). While both colors caused relatively similar changes in the VC and EDA at the position of the first exposure, blue and red light caused greater changes in the VC and EDA, respectively, in the second exposure. There was no significant difference in the subjects' 2-back task performance between the CLE (p = 0.46). The results of this study provide new insights into how human physiology and behavior respond to colored light exposure. Our findings are important for understanding the impact of colored light in our daily lives and its potential applications in a variety of settings, including education, the workplace and healthcare.
Collapse
Affiliation(s)
- Hamoon Zohdi
- Institute of Complementary and Integrative Medicine, University of Bern, 3012 Bern, Switzerland; Biomedical Optics Research Laboratory, Department of Neonatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland.
| | - Josefa Märki
- Institute of Complementary and Integrative Medicine, University of Bern, 3012 Bern, Switzerland
| | - Felix Scholkmann
- Institute of Complementary and Integrative Medicine, University of Bern, 3012 Bern, Switzerland; Biomedical Optics Research Laboratory, Department of Neonatology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland
| | - Ursula Wolf
- Institute of Complementary and Integrative Medicine, University of Bern, 3012 Bern, Switzerland
| |
Collapse
|
4
|
Mahoney HL, Schmidt TM. The cognitive impact of light: illuminating ipRGC circuit mechanisms. Nat Rev Neurosci 2024; 25:159-175. [PMID: 38279030 DOI: 10.1038/s41583-023-00788-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2023] [Indexed: 01/28/2024]
Abstract
Ever-present in our environments, light entrains circadian rhythms over long timescales, influencing daily activity patterns, health and performance. Increasing evidence indicates that light also acts independently of the circadian system to directly impact physiology and behaviour, including cognition. Exposure to light stimulates brain areas involved in cognition and appears to improve a broad range of cognitive functions. However, the extent of these effects and their mechanisms are unknown. Intrinsically photosensitive retinal ganglion cells (ipRGCs) have emerged as the primary conduit through which light impacts non-image-forming behaviours and are a prime candidate for mediating the direct effects of light on cognition. Here, we review the current state of understanding of these effects in humans and mice, and the tools available to uncover circuit-level and photoreceptor-specific mechanisms. We also address current barriers to progress in this area. Current and future efforts to unravel the circuits through which light influences cognitive functions may inform the tailoring of lighting landscapes to optimize health and cognitive function.
Collapse
Affiliation(s)
- Heather L Mahoney
- Department of Neurobiology, Northwestern University, Evanston, IL, USA.
| | - Tiffany M Schmidt
- Department of Neurobiology, Northwestern University, Evanston, IL, USA.
| |
Collapse
|
5
|
Hilditch CJ, Pradhan S, Costedoat G, Bathurst NG, Glaros Z, Gregory KB, Shattuck NL, Flynn-Evans EE. An at-home evaluation of a light intervention to mitigate sleep inertia symptoms. Sleep Health 2024; 10:S121-S129. [PMID: 37679265 DOI: 10.1016/j.sleh.2023.07.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 07/17/2023] [Accepted: 07/21/2023] [Indexed: 09/09/2023]
Abstract
OBJECTIVES Under laboratory settings, light exposure upon waking at night improves sleep inertia symptoms. We investigated whether a field-deployable light source would mitigate sleep inertia in a real-world setting. METHODS Thirty-six participants (18 female; 26.6 years ± 6.1) completed an at-home, within-subject, randomized crossover study. Participants were awoken 45 minutes after bedtime and wore light-emitting glasses with the light either on (light condition) or off (control). A visual 5-minute psychomotor vigilance task, Karolinska sleepiness scale, alertness and mood scales, and a 3-minute auditory/verbal descending subtraction task were performed at 2, 12, 22, and 32 minutes after awakening. Participants then went back to sleep and were awoken after 45 minutes for the opposite condition. A series of mixed-effect models were performed with fixed effects of test bout, condition, test bout × condition, a random effect of the participant, and relevant covariates. RESULTS Participants rated themselves as more alert (p = .01) and energetic (p = .001) in the light condition compared to the control condition. There was no effect of condition for descending subtraction task outcomes when including all participants, but there was a significant improvement in descending subtraction task total responses in the light condition in the subset of participants waking from N3 (p = .03). There was a significant effect of condition for psychomotor vigilance task outcomes, with faster responses (p < .001) and fewer lapses (p < .001) in the control condition. CONCLUSIONS Our findings suggest that light modestly improves self-rated alertness and energy after waking at home regardless of sleep stage, with lower aggression and improvements to working memory only after waking from N3. Contrary to laboratory studies, we did not observe improved performance on the psychomotor vigilance task. Future studies should include measures of visual acuity and comfort to assess the feasibility of interventions in real-world settings.
Collapse
Affiliation(s)
- Cassie J Hilditch
- Fatigue Countermeasures Laboratory, San José State University, San José, California, USA.
| | - Sean Pradhan
- Fatigue Countermeasures Laboratory, San José State University, San José, California, USA; School of Business, Menlo College, Atherton, California, USA
| | - Gregory Costedoat
- Fatigue Countermeasures Laboratory, San José State University, San José, California, USA
| | - Nicholas G Bathurst
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, California, USA
| | - Zachary Glaros
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, California, USA
| | - Kevin B Gregory
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, California, USA
| | - Nita L Shattuck
- Operations Research Department, Naval Postgraduate School, Monterey, California, USA
| | - Erin E Flynn-Evans
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, California, USA
| |
Collapse
|
6
|
Campbell I, Sharifpour R, Vandewalle G. Light as a Modulator of Non-Image-Forming Brain Functions—Positive and Negative Impacts of Increasing Light Availability. Clocks Sleep 2023; 5:116-140. [PMID: 36975552 PMCID: PMC10047820 DOI: 10.3390/clockssleep5010012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/17/2023] [Accepted: 03/13/2023] [Indexed: 03/19/2023] Open
Abstract
Light use is rising steeply, mainly because of the advent of light-emitting diode (LED) devices. LEDs are frequently blue-enriched light sources and may have different impacts on the non-image forming (NIF) system, which is maximally sensitive to blue-wavelength light. Most importantly, the timing of LED device use is widespread, leading to novel light exposure patterns on the NIF system. The goal of this narrative review is to discuss the multiple aspects that we think should be accounted for when attempting to predict how this situation will affect the NIF impact of light on brain functions. We first cover both the image-forming and NIF pathways of the brain. We then detail our current understanding of the impact of light on human cognition, sleep, alertness, and mood. Finally, we discuss questions concerning the adoption of LED lighting and screens, which offer new opportunities to improve well-being, but also raise concerns about increasing light exposure, which may be detrimental to health, particularly in the evening.
Collapse
|
7
|
Yang CC, Tsujimura SI, Yeh SL. Blue-light background impairs visual exogenous attention shift. Sci Rep 2023; 13:3794. [PMID: 36882407 PMCID: PMC9992692 DOI: 10.1038/s41598-022-24862-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 11/22/2022] [Indexed: 03/09/2023] Open
Abstract
Previous research into the effects of blue light on visual-spatial attention has yielded mixed results due to a lack of properly controlling critical factors like S-cone stimulation, ipRGCs stimulation, and color. We adopted the clock paradigm and systematically manipulated these factors to see how blue light impacts the speed of exogenous and endogenous attention shifts. Experiments 1 and 2 revealed that, relative to the control light, exposure to the blue-light background decreased the speed of exogenous (but not endogenous) attention shift to external stimuli. To further clarify the contribution(s) of blue-light sensitive photoreceptors (i.e., S-cone and ipRGCs), we used a multi-primary system that could manipulate the stimulation of a single type of photoreceptor without changing the stimulation of other photoreceptors (i.e., the silent substitution method). Experiments 3 and 4 revealed that stimulation of S-cones and ipRGCs did not contribute to the impairment of exogenous attention shift. Our findings suggest that associations with blue colors, such as the concept of blue light hazard, cause exogenous attention shift impairment. Some of the previously documented blue-light effects on cognitive performances need to be reevaluated and reconsidered in light of our findings.
Collapse
Affiliation(s)
- Chien-Chun Yang
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Sei-Ichi Tsujimura
- Faculty of Design and Architecture, Nagoya City University, Nagoya, Japan
| | - Su-Ling Yeh
- Department of Psychology, National Taiwan University, Taipei, Taiwan.
- Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan.
- Center for Artificial Intelligence and Advanced Robotics, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
8
|
Kumari J, Das K, Babaei M, Rokni GR, Goldust M. The impact of blue light and digital screens on the skin. J Cosmet Dermatol 2023; 22:1185-1190. [PMID: 36594795 DOI: 10.1111/jocd.15576] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 11/21/2022] [Accepted: 12/01/2022] [Indexed: 01/04/2023]
Abstract
INTRODUCTION The skin is frequently subjected to a variety of environmental trauma and stress. It is unavoidably subjected to blue light due to the increased use of electronic equipment, including indoor lighting and digital gadgets like smartphones and laptops, which have a range of detrimental effects. The method of action and numerous harmful consequences of blue light on the skin are the main subjects of this review. MATERIALS AND METHODS A literature search has been performed using PubMed, GoogleScholar and EmBase databases and an updated review on the topic has been presented. RESULTS Numerous studies have shown that being exposed to blue light accelerates the aging process and produces cutaneous hyperpigmentation. It also modifies the circadian rhythm. The two main molecules that mediate cellular responses to blue light are nitric oxide (NO) and reactive oxygen species. However, the precise process is still not fully known. CONCLUSION These negative consequences may eventually cause more general skin damage, which may hasten the aging process. At times, skin protection may be crucial for protection against blue light.
Collapse
Affiliation(s)
- Jyoti Kumari
- Silchar Medical College and Hospital, Silchar, Assam, India
| | - Kinnor Das
- Consultant Dermatolgist, Apollo clinic, Silchar, Assam, India
| | - Mahsa Babaei
- School of Medicine, Stanford University, Stanford, California, USA
| | - Ghasem Rahmatpour Rokni
- Department of Dermatology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohamad Goldust
- Department of Dermatology, University Medical Center Mainz, Mainz, Germany
| |
Collapse
|
9
|
Chen Y, Ma T, Ye Z, Li Z. Effect of illuminance and colour temperature of LED lighting on asthenopia during reading. Ophthalmic Physiol Opt 2023; 43:73-82. [PMID: 36181399 DOI: 10.1111/opo.13051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/19/2022] [Accepted: 08/19/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE A self-controlled study to determine the influence of illuminance and correlated colour temperature (CCT) of light-emitting diode (LED) lighting on asthenopia. METHODS Twenty-two healthy postgraduates (nine women) were recruited to read under eight LED lighting conditions with four illuminances (300 lx, 500 lx, 750 lx and 1000 lx) and four CCTs (2700, 4000, 5000 and 6500 K) for 2 h. A subjective asthenopia questionnaire, the optical quality analysis system (OQAS) and an inflammatory cytokine assay were used to assess the levels of asthenopia. RESULTS Increased asthenopia was observed after reading, but the degree varied with lighting conditions. There were significant differences among the groups in terms of subjective symptoms (inattention, eye pain, dry eye and total score), optical performance parameters (modulation transfer function [MTF] cut-off frequency, Strehl ratio [SR], objective scattering index [OSI], mean OSI and accommodative amplitude [AA]) as well as inflammatory cytokines in the tears (epidermal growth factor [EGF], transforming growth factor [TGF]-α, interleukin [IL]-6, IL-8, macrophage inflammatory protein [MIP]-1β, tumour necrosis factor [TNF]-α, TNF-β and vascular endothelial growth factor [VEGF]-A). All of the subjective and objective measurements collectively suggested that asthenopia was lessened for the 500 lx-4000 K condition. However, asthenopia was significantly worse for 300 lx-2700 K and 1000 lx-6500 K in terms of subjective symptoms and objective optical performance, respectively. CONCLUSIONS LED illuminance and CCT do have a significant effect on asthenopia during reading. 500 lx-4000 K lighting resulted in the lowest level of asthenopia. Conversely, low illuminance at low CCT (300 lx-2700 K) and high illuminance at high CCT (1000 lx-6500 K) promoted more severe asthenopia.
Collapse
Affiliation(s)
- Yilin Chen
- School of Medicine, Nankai University, Tianjin, China
| | - Tianju Ma
- Department of Ophthalmology, The Chinese People's Liberation Army, General Hospital, Beijing, China
| | - Zi Ye
- School of Medicine, Nankai University, Tianjin, China.,Department of Ophthalmology, The Chinese People's Liberation Army, General Hospital, Beijing, China
| | - Zhaohui Li
- School of Medicine, Nankai University, Tianjin, China.,Department of Ophthalmology, The Chinese People's Liberation Army, General Hospital, Beijing, China
| |
Collapse
|
10
|
Rahman SA, Kent BA, Grant LK, Clark T, Hanifin JP, Barger LK, Czeisler CA, Brainard GC, St Hilaire MA, Lockley SW. Effects of dynamic lighting on circadian phase, self-reported sleep and performance during a 45-day space analog mission with chronic variable sleep deficiency. J Pineal Res 2022; 73:e12826. [PMID: 35996978 DOI: 10.1111/jpi.12826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/29/2022] [Accepted: 08/20/2022] [Indexed: 10/15/2022]
Abstract
Spaceflight exposes crewmembers to circadian misalignment and sleep loss, which impair cognition and increase the risk of errors and accidents. We compared the effects of an experimental dynamic lighting schedule (DLS) with a standard static lighting schedule (SLS) on circadian phase, self-reported sleep and cognition during a 45-day simulated space mission. Sixteen participants (mean age [±SD] 37.4 ± 6.7 years; 5 F; n = 8/lighting condition) were studied in four-person teams at the NASA Human Exploration Research Analog. Participants were scheduled to sleep 8 h/night on two weekend nights, 5 h/night on five weekday nights, repeated for six 7-day cycles, with scheduled waketime fixed at 7:00 a.m. Compared to the SLS where illuminance and spectrum remained constant during wake (~4000K), DLS increased the illuminance and short-wavelength (blue) content of white light (~6000K) approximately threefold in the main workspace (Level 1), until 3 h before bedtime when illuminance was reduced by ~96% and the blue content also reduced throughout (~4000K × 2 h, ~3000K × 1 h) until bedtime. The average (±SE) urinary 6-sulphatoxymelatonin (aMT6s) acrophase time was significantly later in the SLS (6.22 ± 0.34 h) compared to the DLS (4.76 ± 0.53 h) and more variable in SLS compared to DLS (37.2 ± 3.6 min vs. 28.2 ± 2.4 min, respectively, p = .04). Compared to DLS, self-reported sleep was more frequently misaligned relative to circadian phase in SLS RR: 6.75, 95% CI 1.55-29.36, p = .01), but neither self-reported sleep duration nor latency to sleep was different between lighting conditions. Accuracy in the abstract matching and matrix reasoning tests were significantly better in DLS compared to SLS (false discovery rate-adjusted p ≤ .04). Overall, DLS alleviated the drift in circadian phase typically observed in space analog studies and reduced the prevalence of self-reported sleep episodes occurring at an adverse circadian phase. Our results support incorporating DLS in future missions, which may facilitate appropriate circadian alignment and reduce the risk of sleep disruption.
Collapse
Affiliation(s)
- Shadab A Rahman
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Brianne A Kent
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Leilah K Grant
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | | | - John P Hanifin
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Laura K Barger
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Charles A Czeisler
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - George C Brainard
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Melissa A St Hilaire
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Steven W Lockley
- Departments of Medicine and Neurology, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
11
|
Akansha EO, Bui BV, Ganeshrao SB, Bakthavatchalam P, Gopalakrishnan S, Mattam S, Poojary RR, Jathanna JS, Jose J, Theruveethi NN. Blue-Light-Blocking Lenses Ameliorate Structural Alterations in the Rodent Hippocampus. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:12922. [PMID: 36232222 PMCID: PMC9564388 DOI: 10.3390/ijerph191912922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/29/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Evidence suggests that prolonged blue-light exposure can impact vision; however, less is known about its impact on non-visual higher-order functions in the brain, such as learning and memory. Blue-light-blocking lenses (BBLs) claim to reduce these potential impacts. Hence, we assessed structural and functional hippocampal alterations following blue-light exposure and the protective efficacy of BBLs. Male Wistar rats were divided into (n = 6 in each group) normal control (NC), blue-light exposure (LE), and blue-light with BBLs (Crizal Prevencia, CP and DuraVision Blue, DB) groups. After 28 days of light exposure (12:12 light: dark cycle), rats were trained for the Morris water maze memory retention test, and brain tissues were sectioned for hippocampal neuronal analysis using Golgi and Cresyl violet stains. The memory retention test was significantly delayed (p < 0.05) in LE compared with DB groups on day 1 of training. Comparison of Golgi-stained neurons showed significant structural alterations, particularly in the basal dendrites of hippocampal neurons in the LE group, with BBLs significantly mitigating these structural changes (p < 0.05). Comparison of Cresyl-violet-stained neurons revealed significantly (p < 0.001) increased degenerated hippocampal neurons in LE rats, with fewer degenerated neurons in the CP lens group for CA1 neurons (p < 0.05), and for both CP and DB groups (p < 0.05) for CA3 neurons. Thus, in addition to documented effects on visual centers, high-level blue-light exposure also results in degeneration in hippocampal neurons with associated behavioral deficits. These changes can be partially ameliorated with blue-light-blocking lenses.
Collapse
Affiliation(s)
- Elizebeth O. Akansha
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Bang V. Bui
- Department of Optometry & Vision Sciences, School of Health Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - Shonraj B. Ganeshrao
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
- INSOFE Education, upGrad-INSOFE, Hyderabad 500034, India
| | - Pugazhandhi Bakthavatchalam
- Department of Anatomy, Melaka Manipal Medical College (Manipal Campus), Manipal Academy of Higher Education, Manipal 576104, India
| | - Sivakumar Gopalakrishnan
- Department of Physiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal 576104, India
| | - Susmitha Mattam
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Radhika R. Poojary
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Judith S. Jathanna
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Judy Jose
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| | - Nagarajan N. Theruveethi
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal 576104, India
| |
Collapse
|
12
|
Vanuk JR, Pace-Schott EF, Bullock A, Esbit S, Dailey NS, Killgore WDS. Morning blue light treatment improves sleep complaints, symptom severity, and retention of fear extinction memory in post-traumatic stress disorder. Front Behav Neurosci 2022; 16:886816. [PMID: 36172467 PMCID: PMC9510714 DOI: 10.3389/fnbeh.2022.886816] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Disrupted sleep is a major feature in numerous clinical disorders and is related to decrements in affective memory processing. The prevalence of sleep disruption in post-traumatic stress disorder (PTSD) is suggested to be a key feature that exacerbates the impaired ability to recall extinction memories during experimental fear conditioning. We hypothesized that an intervention employing blue-wavelength light therapy (BLT) to regulate sleep and stabilize circadian rhythms in patients with PTSD (i.e., via regulated morning exposure) would be associated with PTSD symptom improvement, decreased sleep-related complaints, as well as improved consolidation and retention of extinction memories relative to a fear conditioning/extinction paradigm. Eighty-two individuals with PTSD underwent a well-validated fear conditioning/extinction protocol with subsequent assignment to receive morning BLUE (BLT) or placebo AMBER (ALT) light therapy daily for 30-min over 6-weeks. Participants returned after the intervention for post-treatment extinction recall, comprised of exposure to the previously conditioned stimuli, with the difference in skin conductance response between the "extinguished" and the "never-extinguished" stimuli at follow-up. Participants also viewed previously conditioned stimuli in a novel context during a functional magnetic resonance imaging (fMRI) scan. BLUE light therapy was associated with improvements relative to correlated decreases between PTSD symptoms and sleep-related complaints. Participants receiving BLT also sustained retention of the extinction memory, while those in the placebo amber light treatment group showed impairment, characterized by the restoration of the extinguished fear response after 6-weeks. Participants in the ALT also demonstrated greater reactivity in the left insula when viewing the previously extinguished fear-conditioned stimuli in a novel context. Daily BLUE-wavelength morning light exposure was associated with greater retention of extinction learning in patients with PTSD when compared to ALT, as supported by both autonomic and neurobiological reactivity. We speculate that improved sleep facilitated by a stabilized circadian rhythm, after fear-learning, led to greater consolidation of the fear extinction memory, decreased PTSD symptom presentation, and associated decreases in sleep-related complaints. Prominent exposure treatments for PTSD incorporate principles of fear extinction, and our findings suggest that blue light treatment may facilitate treatment gains by promoting the consolidation of extinction memories via improved sleep.
Collapse
Affiliation(s)
- John R. Vanuk
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Edward F. Pace-Schott
- Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States
| | - Ayla Bullock
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Simon Esbit
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Natalie S. Dailey
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - William D. S. Killgore
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
13
|
Silvani MI, Werder R, Perret C. The influence of blue light on sleep, performance and wellbeing in young adults: A systematic review. Front Physiol 2022; 13:943108. [PMID: 36051910 PMCID: PMC9424753 DOI: 10.3389/fphys.2022.943108] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction: Blue light from electronic devices has a bad reputation. It has a wavelength which may influence our circadian rhythm and cause bad sleep. But there are other aspects of blue light exposure which are often overlooked, for example, it may influence performance and wellbeing. However, few resources summarize its effects systematically. Therefore, the goal of this systematic review was to distil the present evidence on blue light exposure and its influence on sleep, performance and wellbeing and discuss its significance for athletes.Methods: The databases that were searched were Cochrane, Embase, Pubmed, Scopus, and Virtual Health Library. The studies included investigated the influence of blue light exposure on either sleep, performance, wellbeing or a combination of those parameters on healthy humans. Quality assessment was done based on the quantitative assessment tool “QualSyst.”Results: Summarizing the influence of blue light exposure, the following results were found (expressed as proportion to the number of studies investigating the particular parameter): Fifty percent of studies found tiredness to be decreased. One fifth of studies found sleep quality to be decreased and one third found sleep duration to be decreased. Half of the studies found sleep efficacy to be decreased and slightly less than half found sleep latency to be increased. More than one half of the studies found cognitive performance to be increased. Slightly more than two thirds found alertness to be increased and reaction time to be decreased. Slightly less than half of the studies found wellbeing to be increased.Conclusion: Blue light exposure can positively affect cognitive performance, alertness, and reaction time. This might benefit sports reliant on team-work and decision-making and may help prevent injury. Blue light might also have negative effects such as the decrease in sleep quality and sleep duration, which might worsen an athlete’s physical and cognitive performance and recovery. Further research should explore if blue light can improve sleep, performance and wellbeing to significantly benefit athletic performance.
Collapse
Affiliation(s)
| | - Robert Werder
- Institute of Sports Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland
| | - Claudio Perret
- Institute of Sports Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland
- *Correspondence: Claudio Perret,
| |
Collapse
|
14
|
Luxotonic signals in human prefrontal cortex as a possible substrate for effects of light on mood and cognition. Proc Natl Acad Sci U S A 2022; 119:e2118192119. [PMID: 35867740 PMCID: PMC9282370 DOI: 10.1073/pnas.2118192119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Studies with experimental animals have revealed a mood-regulating neural pathway linking intrinsically photosensitive retinal ganglion cells (ipRGCs) and the prefrontal cortex (PFC), involved in the pathophysiology of mood disorders. Since humans also have light-intensity-encoding ipRGCs, we asked whether a similar pathway exists in humans. Here, functional MRI was used to identify PFC regions and other areas exhibiting light-intensity-dependent signals. We report 26 human brain regions having activation that either monotonically decreases or monotonically increases with light intensity. Luxotonic-related activation occurred across the cerebral cortex, in diverse subcortical structures, and in the cerebellum, encompassing regions with functions related to visual image formation, motor control, cognition, and emotion. Light suppressed PFC activation, which monotonically decreased with increasing light intensity. The sustained time course of light-evoked PFC responses and their susceptibility to prior light exposure resembled those of ipRGCs. These findings offer a functional link between light exposure and PFC-mediated cognitive and affective phenomena.
Collapse
|
15
|
Kim T, Kim S, Kang J, Kwon M, Lee SH. The Common Effects of Sleep Deprivation on Human Long-Term Memory and Cognitive Control Processes. Front Neurosci 2022; 16:883848. [PMID: 35720688 PMCID: PMC9201256 DOI: 10.3389/fnins.2022.883848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/11/2022] [Indexed: 11/17/2022] Open
Abstract
Sleep deprivation is known to have adverse effects on various cognitive abilities. In particular, a lack of sleep has been reported to disrupt memory consolidation and cognitive control functions. Here, focusing on long-term memory and cognitive control processes, we review the consistency and reliability of the results of previous studies of sleep deprivation effects on behavioral performance with variations in the types of stimuli and tasks. Moreover, we examine neural response changes related to these behavioral changes induced by sleep deprivation based on human fMRI studies to determine the brain regions in which neural responses increase or decrease as a consequence of sleep deprivation. Additionally, we discuss about the possibility that light as an environmentally influential factor affects our sleep cycles and related cognitive processes.
Collapse
Affiliation(s)
- Taehyun Kim
- Department of Bio and Brain Engineering, College of Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Sejin Kim
- Department of Bio and Brain Engineering, College of Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Joonyoung Kang
- Department of Bio and Brain Engineering, College of Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- Program of Brain and Cognitive Engineering, College of Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Minjae Kwon
- Department of Bio and Brain Engineering, College of Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Sue-Hyun Lee
- Department of Bio and Brain Engineering, College of Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- Program of Brain and Cognitive Engineering, College of Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- *Correspondence: Sue-Hyun Lee,
| |
Collapse
|
16
|
Lok R, Joyce DS, Zeitzer JM. Impact of daytime spectral tuning on cognitive function. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 230:112439. [PMID: 35398657 DOI: 10.1016/j.jphotobiol.2022.112439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
Light at night can improve alertness and cognition. Exposure to daytime light, however, has yielded less conclusive results. In addition to direct effects, daytime light may also mitigate the impact of nocturnal light exposure on alertness. To examine the impact of daytime lighting on daytime cognitive performance, and evening alertness, we studied nine healthy individuals using a within subject crossover design. On four visits, participants were exposed to one of four lighting conditions for 10 h (dim fluorescent, room fluorescent, broad-spectrum LED, standard white LED; the latter three conditions were matched for 100 lx) followed by an exposure to bright evening light. Cognitive performance, subjective and objective measures of alertness were regularly obtained. While daytime alertness was not impacted by light exposure, the broad-spectrum LED light improved several aspects of daytime cognition. The impact of evening light on alertness was not mitigated by the pre-exposure to different daytime lighting conditions. Results suggest that daytime exposure to white light with high melanopic efficacy has the potential to improve daytime cognitive function and that such improvements are likely to be direct rather than a consequence of light-induced changes in alertness.
Collapse
Affiliation(s)
- Renske Lok
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, United States of America
| | - Daniel S Joyce
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, United States of America; Department of Psychology, University of Nevada, Reno, Reno, NV 89557, United States of America
| | - Jamie M Zeitzer
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, United States of America; Mental Illness Research Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA 94304, United States of America.
| |
Collapse
|
17
|
Killgore WD, Alkozei A, Vanuk JR, Reign D, Grandner MA, Dailey NS. Blue light exposure increases functional connectivity between dorsolateral prefrontal cortex and multiple cortical regions. Neuroreport 2022; 33:236-241. [PMID: 35287149 PMCID: PMC8966738 DOI: 10.1097/wnr.0000000000001774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/12/2022] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Blue light is a powerful environmental stimulus that can produce significant phase shifts in the circadian rhythm of melatonin and sleep propensity as well as acute effects on alertness of neurobehavioral performance. Here, we undertook an expansion and reanalysis of our previously published findings to examine the effect of acute blue light exposure on the strength of resting-state functional connectivity (rsFC) between a previously identified region of the left dorsolateral prefrontal cortex (DLPFC) and 106 cortical and subcortical regions. METHODS Twenty-nine healthy adults (16 men and 13 women; age 18-32 years) completed a psychomotor vigilance test (PVT) before and after a single 30-min exposure to either blue (λ = 469 nm; n = 17) or amber wavelength (λ = 578 nm; n = 12) light, immediately followed by an rsFC scan. RESULTS Compared with amber light, blue light exposure produced significantly greater functional connectivity between the left DLPFC seed region and 30 cortical and subcortical regions (P < 0.05; false discovery rate-corrected). Although neurobehavioral performance did not differ between light conditions, only those exposed to blue light showed a significant association between rsFC and sustained PVT performance. Better sustained PVT performance was associated with greater connectivity between the left DLPFC and regions associated with visuospatial awareness/motion detection (right temporal-occipital middle temporal gyrus) and memory (left hippocampus), as well as reduced connectivity in a circuit associated with cognitive rumination and distraction (left parahippocampal gyrus). CONCLUSION Findings suggest that blue-wavelength light may facilitate acute alertness and improved cognitive performance through enhanced rsFC between the left DLPFC and cortical regions associated with visuospatial awareness.
Collapse
Affiliation(s)
- William D.S. Killgore
- Department of Psychiatry, Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, Arizona, USA
| | - Anna Alkozei
- Department of Psychiatry, Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, Arizona, USA
| | - John R. Vanuk
- Department of Psychiatry, Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, Arizona, USA
| | - Deva Reign
- Department of Psychiatry, Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, Arizona, USA
| | - Michael A. Grandner
- Department of Psychiatry, Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, Arizona, USA
| | - Natalie S. Dailey
- Department of Psychiatry, Social, Cognitive, and Affective Neuroscience Laboratory, University of Arizona, Tucson, Arizona, USA
| |
Collapse
|
18
|
Lin Z, Hou G, Yao Y, Zhou Z, Zhu F, Liu L, Zeng L, Yang Y, Ma J. 40-Hz Blue Light Changes Hippocampal Activation and Functional Connectivity Underlying Recognition Memory. Front Hum Neurosci 2022; 15:739333. [PMID: 34975431 PMCID: PMC8716555 DOI: 10.3389/fnhum.2021.739333] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/19/2021] [Indexed: 12/04/2022] Open
Abstract
Research on light modulation has typically examined the wavelength, intensity, and exposure time of light, and measured rhythm, sleep, and cognitive ability to evaluate the regulatory effects of light variables on physiological and cognitive functions. Although the frequency of light is one of the main dimensions of light, few studies have attempted to manipulate it to test the effect on brain activation and performance. Recently, 40-Hz light stimulation has been proven to significantly alleviate deficits in gamma oscillation of the hippocampus caused by Alzheimer’s disease. Although this oscillation is one of the key functional characteristics of performing memory tasks in healthy people, there is no evidence that 40-Hz blue light exposure can effectively regulate brain activities related to complex cognitive tasks. In the current study, we examined the difference in the effects of 40-Hz light or 0-Hz light exposure on brain activation and functional connectivity during a recognition memory task. Through joint augmentation of visual area activation, 40-Hz light enhanced brain areas mostly in the limbic system that are related to memory, such as the hippocampus and thalamus. Conversely, 0-Hz light enhanced brain areas mostly in the prefrontal cortex. Additionally, functional connection analysis, with the hippocampus as the seed point, showed that 40-Hz light enhanced connection with the superior parietal lobe and reduced the connection with the default network. These results indicate that light at a frequency of 40 Hz can change the activity and functional connection of memory-related core brain areas. They also indicate that in the use of light to regulate cognitive functions, its frequency characteristics merit attention.
Collapse
Affiliation(s)
- Zhenglong Lin
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen, China
| | - Gangqiang Hou
- Department of Radiology, Shenzhen Kangning Hospital, Shenzhen Mental Health Center, Shenzhen, China
| | - Youli Yao
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen University, Shenzhen, China
| | - Zhifeng Zhou
- Department of Radiology, Shenzhen Kangning Hospital, Shenzhen Mental Health Center, Shenzhen, China
| | - Feiqi Zhu
- Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University Medical College, Shenzhen, China
| | - Linjing Liu
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen, China
| | - Lingwu Zeng
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen, China
| | - Yatao Yang
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen, China
| | - Junxian Ma
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen, China
| |
Collapse
|
19
|
Daily Morning Blue Light Therapy Improves Daytime Sleepiness, Sleep Quality, and Quality of Life Following a Mild Traumatic Brain Injury. J Head Trauma Rehabil 2021; 35:E405-E421. [PMID: 32472836 DOI: 10.1097/htr.0000000000000579] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Identify the treatment effects of 6 weeks of daily 30-minute sessions of morning blue light therapy compared with placebo amber light therapy in the treatment of sleep disruption following mild traumatic brain injury. DESIGN Placebo-controlled randomized trial. PARTICIPANTS Adults aged 18 to 45 years with a mild traumatic brain injury within the past 18 months (n = 35). MAIN OUTCOME MEASURES Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Beck Depression Inventory II, Rivermead Post-concussion Symptom Questionnaire, Functional Outcomes of Sleep Questionnaire, and actigraphy-derived sleep measures. RESULTS Following treatment, moderate to large improvements were observed with individuals in the blue light therapy group reporting lower Epworth Sleepiness Scale (Hedges' g = 0.882), Beck Depression Inventory II (g = 0.684), Rivermead Post-concussion Symptom Questionnaire chronic (g = 0.611), and somatic (g = 0.597) symptoms, and experiencing lower normalized wake after sleep onset (g = 0.667) than those in the amber light therapy group. In addition, individuals in the blue light therapy group experienced greater total sleep time (g = 0.529) and reported improved Functional Outcomes of Sleep Questionnaire scores (g = 0.929) than those in the amber light therapy group. CONCLUSION Daytime sleepiness, fatigue, and sleep disruption are common following a mild traumatic brain injury. These findings further substantiate blue light therapy as a promising nonpharmacological approach to improve these sleep-related complaints with the added benefit of improved postconcussion symptoms and depression severity.
Collapse
|
20
|
Song Y, Lv X, Qin W, Dang W, Chen Z, Nie J, Liu B, Dong W. The Effect of Blue-enriched White Light on Cognitive Performances and Sleepiness of Simulated Shift Workers: A Randomized Controlled Trial. J Occup Environ Med 2021; 63:752-759. [PMID: 33901161 DOI: 10.1097/jom.0000000000002241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Shift work is associated with reduced performance and efficiency, the current study aimed at investigating whether blue-enriched white light could improve workers' performance. METHODS The study, which adopted a randomized controlled trial, was conducted among 48 simulated shift workers. The participants performed sustained attention task, working memory task, and sleepiness task during night shift work. The data was analyzed using two-way repeated measure ANOVA. RESULTS The results indicated that, compared to conventional light, participants' correct responses of the sustained attention significantly increased when they were exposed to blue-enriched white light, correspondingly, the commission errors and omission errors declined. Furthermore, the blue-enriched white light had a significant effect on the decrease of sleepiness. However, the working memory was not significantly affected. CONCLUSION Exposing to blue-enriched white light can improve sustained attention and reduce sleepiness.
Collapse
Affiliation(s)
- Yanping Song
- Peking University Sixth Hospital, Peking University, Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health National Clinical Research Center for Mental Disorders, Haidian District, Beijing 100191, PR China (Song, Dang, Dong); National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Haidian District, Beijing 100191, PR China (Song, Dang, Dong); School of Public Health, Peking University, Haidian District, Beijing, 100191, PR China (Xinrui, Qin, Liu); School of Physics, Peking University, Haidian District, Beijing 100871, PR China (Chen, Nie)
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
People are constantly exposed to blue light while engaging in work. It is thus crucial to understand if vast exposure to blue light influences cognitive control, which is essential for working efficiently. Previous studies proposed that the stimulation of intrinsically photosensitive retinal ganglion cells (ipRGCs), a newly discovered photoreceptor that is highly sensitive to blue light, could modulate non-image forming functions. Despite studies that showed blue light (or ipRGCs) enhances brain activations in regions related to cognitive control, how exposure to blue light changes our cognitive control behaviorally remains elusive. We examined whether blue light influences cognitive control through three behavioral tasks in three studies: the sustained attention to response task (SART), the task-switching paradigm, and the Stroop task. Classic effects of the SART, switch cost, and the Stroop effect were found, but no differences were observed in results of different background lights across the six experiments. Together, we conclude that these domains of cognitive control are not influenced by blue light and ipRGCs, and whether the enhancement of blue light on brain activities extends to the behavioral level should be carefully re-examined.
Collapse
Affiliation(s)
- Hsing-Hao Lee
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Yun-Chen Tu
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Su-Ling Yeh
- Department of Psychology, National Taiwan University, Taipei, Taiwan.
- Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan.
- Center for Artificial Intelligence and Advanced Robotics, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
22
|
Matsuo T, Ishii A, Ishida R, Minami T, Yoshikawa T. Neural correlates of the improvement of cognitive performance resulting from enhanced sense of competence: A magnetoencephalography study. PLoS One 2021; 16:e0255272. [PMID: 34297767 PMCID: PMC8301610 DOI: 10.1371/journal.pone.0255272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 07/13/2021] [Indexed: 11/30/2022] Open
Abstract
The alterations in neural activity related to the improvement of cognitive performance, which would be leading to better academic performance, remain poorly understood. In the present study, we assessed neural activity related to the improvement of task performance resulting from academic rewards. Twenty healthy male volunteers participated in this study. All participants performed four sessions of a 1-back-Stroop task under both target and control conditions. An image indicating that the task performance of each participant was above average and categorized as being at almost the highest level was presented immediately after each session under the target condition, whereas a control image did not indicate task performance. Neural activity during the 1-back-Stroop task was recorded by magnetoencephalography. The correction rate of the 1-back-Stroop task in the final session relative to that in the first under the target condition was increased compared with the control condition. Correlation analysis revealed that the decreases in alpha band power in right Brodmann’s area (BA) 47 and left BA 7 were positively associated with the increased correction rate caused by the target condition. These findings are expected to contribute to a better understanding of the neural mechanisms underlying the improvement of cognitive performance.
Collapse
Affiliation(s)
- Takashi Matsuo
- Department of Sports Medicine, Osaka City University Graduate School of Medicine, Osaka City, Osaka, Japan
| | - Akira Ishii
- Department of Sports Medicine, Osaka City University Graduate School of Medicine, Osaka City, Osaka, Japan
- * E-mail:
| | - Rika Ishida
- Department of Sports Medicine, Osaka City University Graduate School of Medicine, Osaka City, Osaka, Japan
| | - Takayuki Minami
- Department of Sports Medicine, Osaka City University Graduate School of Medicine, Osaka City, Osaka, Japan
| | - Takahiro Yoshikawa
- Department of Sports Medicine, Osaka City University Graduate School of Medicine, Osaka City, Osaka, Japan
| |
Collapse
|
23
|
Li Y, Ru T, Chen Q, Qian L, Luo X, Zhou G. Effects of illuminance and correlated color temperature of indoor light on emotion perception. Sci Rep 2021; 11:14351. [PMID: 34253773 PMCID: PMC8275593 DOI: 10.1038/s41598-021-93523-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/16/2021] [Indexed: 12/01/2022] Open
Abstract
The acute non-image forming (NIF) effects of daytime light on momentary mood had been-although not always-established in the current literature. It still remains largely unknown whether short-time light exposure would modulate emotion perception in healthy adults. The current study (N = 48) was conducted to explore the effects of illuminance (100 lx vs. 1000 lx at eye level) and correlated color temperature (CCT, 2700 K vs. 6500 K) on explicit and implicit emotion perception that was assessed with emotional face judgment task and emotional oddball task respectively. Results showed that lower CCT significantly decreased negative response bias in the face judgment task, with labeling ambiguous faces less fearful under 2700 K vs. 6500 K condition. Moreover, participants responded slightly faster for emotional pictures under 6500 K vs. 2700 K condition, but no significant effect of illuminance or CCT on negativity bias was revealed in the emotional oddball task. These findings highlighted the differential role of illuminance and CCT in regulating instant emotion perception and suggested a task-dependent moderation of light spectrum on negativity bias.
Collapse
Affiliation(s)
- Yun Li
- School of Psychology, South China Normal University, Guangzhou, 510631, China.,Lab of Light and Physio-psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Taotao Ru
- Lab of Light and Physio-psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China. .,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China.
| | - Qingwei Chen
- School of Psychology, South China Normal University, Guangzhou, 510631, China.,Lab of Light and Physio-psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Liu Qian
- School of Psychology, South China Normal University, Guangzhou, 510631, China.,Lab of Light and Physio-psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Xianghang Luo
- School of Psychology, South China Normal University, Guangzhou, 510631, China
| | - Guofu Zhou
- Lab of Light and Physio-psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| |
Collapse
|
24
|
Ige AO, Adekanye OS, Adewoye EO. Intermittent exposure to green and white light-at-night activates hepatic glycogenolytic and gluconeogenetic activities in male Wistar rats. J Basic Clin Physiol Pharmacol 2021:jbcpp-2020-0251. [PMID: 34147042 DOI: 10.1515/jbcpp-2020-0251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 04/15/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Exposure to light-at-night (LAN) has been reported to impair blood glucose regulation. The liver modulates blood glucose through mechanisms influenced by several factors that include peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α) and glucose-6-phosphatase (G6Pase). This study investigated the effect of intermittent exposure to green and white LAN on some hepatic glucose regulatory factors in male Wistar rats. METHODS Animals were divided into three equal groups. Group I (control) was exposed to normal housing conditions. Groups II and III were each daily exposed to either green or white LAN for 2 h (7-9 pm) for 14 days. Body weight and blood glucose was monitored on days 0, 7, and 14. Thereafter, retro-orbital sinus blood was obtained after light thiopental anaesthesia and serum insulin was determined. Liver samples were also obtained and evaluated for glycogen, PGC-1α, and G6Pase activity. Insulin resistance was estimated using the HOMA-IR equation. RESULTS Body weight and blood glucose on days 7 and 14 increased in groups II and III compared to control. Hepatic PGC-1α and G6Pase increased in group II (2.33 ± 0.31; 2.07 ± 0.22) and III (2.31 ± 0.20; 0.98 ± 0.23) compared to control (1.73 ± 0.21; 0.47 ± 0.11). Hepatic glycogen was 71.8 and 82.4% reduced in groups II and III compared to control. Insulin in group II increased (63.6%) whiles group III values reduced (27.3%) compared to control. Insulin resistance increased in group II (0.29 ± 0.09) compared to control (0.12 ± 0.03) and group III (0.11 ± 0.03), respectively. CONCLUSIONS Exposure to 2 h green and white LAN in the early dark phase increases hepatic glycogenolysis and gluconeogenetic activities resulting in increased blood glucose. In male Wistar rats, exposure to green but not white LAN may predispose to insulin resistance.
Collapse
Affiliation(s)
- Abayomi O Ige
- Applied and Environmental Physiology Unit, Department of Physiology, University of Ibadan, Ibadan, Nigeria
| | - Olubori S Adekanye
- Applied and Environmental Physiology Unit, Department of Physiology, University of Ibadan, Ibadan, Nigeria
| | - Elsie O Adewoye
- Applied and Environmental Physiology Unit, Department of Physiology, University of Ibadan, Ibadan, Nigeria
| |
Collapse
|
25
|
Sun W, Yang Y, Chen X, Cheng Y, Li X, An L. Light Promotes Neural Correlates of Fear Memory via Enhancing Brain-Derived Neurotrophic Factor (BDNF) Expression in the Prelimbic Cortex. ACS Chem Neurosci 2021; 12:1802-1810. [PMID: 33961393 DOI: 10.1021/acschemneuro.1c00081] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Exposure to light has been shown to enhance vigilance and improve working memory, possibly due to changes in prefrontal function. Ample evidence supports the critical role of prefrontal cortex (PFC) in fear memory performance. However, the effects of light on memory processing and its potential mechanisms remain unclear. Here, through rats exposure conditioned to light at different memory phases, we sought evidence for the influences by employing behavioral tests, pharmacological infusions, immunoblotting, and electrophysiological recording. Exposure to light immediately following conditioning of 30 min or longer could effectively improve consolidation of fear memory without altering short-term memory or upgrading the original fear. The absence of significant freezing during baseline and intertrial interval periods ruled out the possibility of a general induction of freezing by light. Meanwhile, rats exposed to light in homecages or conditioning chambers exhibited a similar memory phenotype, indicating that light specifically enhanced the fear stimulus rather than the contextual environment. Furthermore, light exposure elevated the training-induced brain-derived neurotrophic factor (BDNF) expression in the prelimbic, but not infralimbic, subregion of the PFC. Moreover, the BDNF-TrkB pathway, but not the BDNF-p75NTR pathway, was involved in light-mediated fear memory. The enhancement in BDNF activity effectively facilitated firing correlates of prelimbic pyramidal neurons but not fast-spiking interneurons. Blocking the training-induced BDNF by its antibody abolished the effects of light on neural function and fear memory. Therefore, our findings indicate that light enhances training-induced BDNF expression that promotes the neural correlate of memory function.
Collapse
Affiliation(s)
- Wei Sun
- Behavioral Neuroscience Laboratory, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
- Department of Pediatric, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
| | - Yang Yang
- Department of Pediatric, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
| | - Xiao Chen
- Behavioral Neuroscience Laboratory, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
| | - Yan Cheng
- Behavioral Neuroscience Laboratory, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
- Department of Pediatric, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
| | - Xiaolian Li
- Department of Neurology, Jinan Rehabilitation Hospital, Jinan 250013, China
| | - Lei An
- Behavioral Neuroscience Laboratory, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
- Department of Pediatric, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
- Department of Neurology, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China
- Department of Physiology, University of Saskatchewan, Saskatoon S7N 5E5, Canada
| |
Collapse
|
26
|
Bajaj S, Raikes AC, Razi A, Miller MA, Killgore WDS. Blue-Light Therapy Strengthens Resting-State Effective Connectivity within Default-Mode Network after Mild TBI. J Cent Nerv Syst Dis 2021; 13:11795735211015076. [PMID: 34104033 PMCID: PMC8145607 DOI: 10.1177/11795735211015076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 02/08/2021] [Indexed: 11/15/2022] Open
Abstract
Background: Emerging evidence suggests that post concussive symptoms, including mood changes, may be improved through morning blue-wavelength light therapy (BLT). However, the neurobiological mechanisms underlying these effects remain unknown. We hypothesize that BLT may influence the effective brain connectivity (EC) patterns within the default-mode network (DMN), particularly involving the medial prefrontal cortex (MPFC), which may contribute to improvements in mood. Methods: Resting-state functional MRI data were collected from 41 healthy-controls (HCs) and 28 individuals with mild traumatic brain injury (mTBI). Individuals with mTBI also underwent a diffusion-weighted imaging scan and were randomly assigned to complete either 6 weeks of daily morning BLT (N = 14) or amber light therapy (ALT; N = 14). Advanced spectral dynamic causal modeling (sDCM) and diffusion MRI connectometry were used to estimate EC patterns and structural connectivity strength within the DMN, respectively. Results: The sDCM analysis showed dominant connectivity pattern following mTBI (pre-treatment) within the hemisphere contralateral to the one observed for HCs. BLT, but not ALT, resulted in improved directional information flow (ie, EC) from the left lateral parietal cortex (LLPC) to MPFC within the DMN. The improvement in EC from LLPC to MPFC was accompanied by stronger structural connectivity between the 2 areas. For the BLT group, the observed improvements in function and structure were correlated (at a trend level) with changes in self-reported happiness. Conclusions: The current preliminary findings provide empirical evidence that morning short-wavelength light therapy could be used as a novel alternative rehabilitation technique for mTBI. Trial registry: The research protocols were registered in the ClinicalTrials.gov database (CT Identifiers NCT01747811 and NCT01721356).
Collapse
Affiliation(s)
- Sahil Bajaj
- Social, Cognitive and Affective Neuroscience (SCAN) Laboratory, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, USA
- Multimodal Clinical Neuroimaging Laboratory (MCNL), Center for Neurobehavioral Research, Boys Town National Research Hospital, Boys Town, NE, USA
- Sahil Bajaj, Multimodal Clinical Neuroimaging Laboratory, Center for Neurobehavioral Research, Boys Town National Research Hospital, 14015 Flanagan Blvd. Suite #102, Boys Town, NE 68010, USA.
| | - Adam C Raikes
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ, USA
| | - Adeel Razi
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, and Monash Biomedical Imaging at Monash University, Clayton, VIC, Australia
- The Wellcome Centre for Human Neuroimaging, University College London, London, UK
- Department of Electronic Engineering, NED University of Engineering and Technology, Karachi, Pakistan
| | - Michael A Miller
- Social, Cognitive and Affective Neuroscience (SCAN) Laboratory, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - William DS Killgore
- Social, Cognitive and Affective Neuroscience (SCAN) Laboratory, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, USA
| |
Collapse
|
27
|
Light-Dependent Effects of Prefrontal rTMS on Emotional Working Memory. Brain Sci 2021; 11:brainsci11040446. [PMID: 33807349 PMCID: PMC8065741 DOI: 10.3390/brainsci11040446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 11/17/2022] Open
Abstract
Growing evidence suggests that colored light exposure can affect several brain functions in addition to conscious visual perception. Blue as compared to green light has especially been shown to enhance alertness and vigilance, as well as cognitive functions. However, the role of light exposure in studies using non-invasive brain stimulation remains unclear. Here, we examined the impact of light on cognitive-emotional effects of prefrontal repetitive transcranial magnetic stimulation (rTMS). In a randomized within-subjects design, twenty participants (12 males, 26 ± 4 years) were exposed to blue or green light prior and concomitant to active or sham rTMS (1Hz, 15min, 110% of the resting motor threshold), applied over the right dorsolateral prefrontal cortex (DLPFC). In each condition, an emotional working memory task (EMOBACK) was presented pre- and post-intervention. Stimuli of the EMOBACK task were positive, negative and neutral words. Our results revealed valence-specific stimulation effects in dependence of colored light exposure. More specifically, task accuracy was significantly increased for positive stimuli under blue light and for negative stimuli under green light exposure. Our findings highlight the importance of state-dependency in studies using non-invasive brain stimulation and show blue light exposure to be a potential adjunctive technique to rTMS for enhancing cognitive-emotional modulation.
Collapse
|
28
|
Alkozei A, Dailey NS, Bajaj S, Vanuk JR, Raikes AC, Killgore WDS. Exposure to Blue Wavelength Light Is Associated With Increases in Bidirectional Amygdala-DLPFC Connectivity at Rest. Front Neurol 2021; 12:625443. [PMID: 33841300 PMCID: PMC8032953 DOI: 10.3389/fneur.2021.625443] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 03/03/2021] [Indexed: 11/13/2022] Open
Abstract
Blue wavelength light has been used successfully as a treatment method for certain mood disorders, but, the underlying mechanisms behind the mood enhancing effects of light remain poorly understood. We investigated the effects of a single dose of 30 min of blue wavelength light (n = 17) vs. amber wavelength light (n = 12) exposure in a sample of healthy adults on subsequent resting-state functional and directed connectivity, and associations with changes in state affect. Individuals who received blue vs. amber wavelength light showed greater positive connectivity between the right amygdala and a region within the left dorsolateral prefrontal cortex (DLPFC). In addition, using granger causality, the findings showed that individuals who received blue wavelength light displayed greater bidirectional information flow between these two regions relative to amber light. Furthermore, the strength of amygdala-DLPFC functional connectivity was associated with greater decreases in negative mood for the blue, but not the amber light condition. Blue light exposure may positively influence mood by modulating greater information flow between the amygdala and the DLPFC, which may result in greater engagement of cognitive control strategies that are needed to perceive and regulate arousal and mood.
Collapse
Affiliation(s)
- Anna Alkozei
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, University of Arizona, Tucson, AZ, United States
| | - Natalie S Dailey
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, University of Arizona, Tucson, AZ, United States
| | - Sahil Bajaj
- Multimodal Clinical Neuroimaging Laboratory (MCNL), Center for Neurobehavioral Research, Boys Town National Research Hospital, Boys Town, NE, United States
| | - John R Vanuk
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, University of Arizona, Tucson, AZ, United States
| | - Adam C Raikes
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, University of Arizona, Tucson, AZ, United States
| | - William D S Killgore
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
29
|
Grant LK, Kent BA, Mayer MD, Stickgold R, Lockley SW, Rahman SA. Daytime Exposure to Short Wavelength-Enriched Light Improves Cognitive Performance in Sleep-Restricted College-Aged Adults. Front Neurol 2021; 12:624217. [PMID: 33692742 PMCID: PMC7937889 DOI: 10.3389/fneur.2021.624217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/29/2021] [Indexed: 11/22/2022] Open
Abstract
We tested the effect of daytime indoor light exposure with varying melanopic strength on cognitive performance in college-aged students who maintained an enforced nightly sleep opportunity of 7 h (i.e., nightly sleep duration no longer than 7 h) for 1 week immediately preceding the day of light exposure. Participants (n = 39; mean age ± SD = 24.5 ± 3.2 years; 21 F) were randomized to an 8 h daytime exposure to one of four white light conditions of equal photopic illuminance (~50 lux at eye level in the vertical plane) but different melanopic illuminance [24–45 melanopic-EDI lux (melEDI)] generated by varying correlated color temperatures [3000K (low-melEDI) or 5000K (high-melEDI)] and spectra [conventional or daylight-like]. Accuracy on a 2-min addition task was 5% better in the daylight-like high-melEDI condition (highest melEDI) compared to the conventional low-melEDI condition (lowest melEDI; p < 0.01). Performance speed on the motor sequence learning task was 3.2 times faster (p < 0.05) during the daylight-like high-melEDI condition compared to the conventional low-melEDI. Subjective sleepiness was 1.5 times lower in the conventional high-melEDI condition compared to the conventional low-melEDI condition, but levels were similar between conventional low- and daylight-like high-melEDI conditions. These results demonstrate that exposure to high-melanopic (short wavelength-enriched) white light improves processing speed, working memory, and procedural learning on a motor sequence task in modestly sleep restricted young adults, and have important implications for optimizing lighting conditions in schools, colleges, and other built environments.
Collapse
Affiliation(s)
- Leilah K Grant
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States
| | - Brianne A Kent
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States
| | - Matthew D Mayer
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States
| | - Robert Stickgold
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, United States.,Department of Psychiatry, Harvard Medical School, Boston, MA, United States
| | - Steven W Lockley
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States
| | - Shadab A Rahman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
30
|
Raikes AC, Dailey NS, Forbeck B, Alkozei A, Killgore WDS. Daily Morning Blue Light Therapy for Post-mTBI Sleep Disruption: Effects on Brain Structure and Function. Front Neurol 2021; 12:625431. [PMID: 33633674 PMCID: PMC7901882 DOI: 10.3389/fneur.2021.625431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/15/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Mild traumatic brain injuries (mTBIs) are associated with novel or worsened sleep disruption. Several studies indicate that daily morning blue light therapy (BLT) is effective for reducing post-mTBI daytime sleepiness and fatigue. Studies demonstrating changes in brain structure and function following BLT are limited. The present study's purpose is to identify the effect of daily morning BLT on brain structure and functional connectivity and the association between these changes and self-reported change in post-mTBI daytime sleepiness. Methods: A total of 62 individuals recovering from a mTBI were recruited from two US cities to participate in a double-blind placebo-controlled trial. Eligible individuals were randomly assigned to undergo 6 weeks of 30 min daily morning blue or placebo amber light therapy (ALT). Prior to and following treatment all individuals completed a comprehensive battery that included the Epworth Sleepiness Scale as a measure of self-reported daytime sleepiness. All individuals underwent a multimodal neuroimaging battery that included anatomical and resting-state functional magnetic resonance imaging. Atlas-based regional change in gray matter volume (GMV) and region-to-region functional connectivity from baseline to post-treatment were the primary endpoints for this study. Results: After adjusting for pre-treatment GMV, individuals receiving BLT had greater GMV than those receiving amber light in 15 regions of interest, including the right thalamus and bilateral prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with greater GMV in 74 ROIs, covering many of the same general regions. Likewise, BLT was associated with increased functional connectivity between the thalamus and both prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with increased functional connectivity between attention and cognitive control networks as well as decreased connectivity between visual, motor, and attention networks (all FDR corrected p < 0.05). Conclusions: Following daily morning BLT, moderate to large increases in both gray matter volume and functional connectivity were observed in areas and networks previously associated with both sleep regulation and daytime cognitive function, alertness, and attention. Additionally, these findings were associated with improvements in self-reported daytime sleepiness. Further work is needed to identify the personal characteristics that may selectively identify individuals recovering from a mTBI for whom BLT may be optimally beneficial.
Collapse
Affiliation(s)
- Adam C Raikes
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ, United States
| | - Natalie S Dailey
- Social, Cognitive, and Affective Neuroscience Lab, University of Arizona, Tucson, AZ, United States
| | - Brittany Forbeck
- Social, Cognitive, and Affective Neuroscience Lab, University of Arizona, Tucson, AZ, United States
| | - Anna Alkozei
- Social, Cognitive, and Affective Neuroscience Lab, University of Arizona, Tucson, AZ, United States
| | - William D S Killgore
- Social, Cognitive, and Affective Neuroscience Lab, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
31
|
Jahrami H, Abdelaziz A, Binsanad L, Alhaj OA, Buheji M, Bragazzi NL, Saif Z, BaHammam AS, Vitiello MV. The Association between Symptoms of Nomophobia, Insomnia and Food Addiction among Young Adults: Findings of an Exploratory Cross-Sectional Survey. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18020711. [PMID: 33467561 PMCID: PMC7830658 DOI: 10.3390/ijerph18020711] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/09/2021] [Accepted: 01/12/2021] [Indexed: 12/12/2022]
Abstract
No previous research has examined the association between symptoms of nomophobia and food addiction. Similarly, only a few studies have examined the association between nomophobia and symptoms of insomnia. This exploratory study utilized an online self-administered, structured questionnaire that included: basic sociodemographic and anthropometrics; the nomophobia questionnaire (NMP-Q); the insomnia severity index (ISI); and the Yale Food Addiction Scale (YFAS) in a convenience sample of young adults (18–35 years) in Bahrain (n = 654), 304 (46%) males and 350 (54%) females. Symptoms of severe nomophobia, moderate-severe insomnia, and food addiction were more common among female participants both for each disorder separately and in combination; however, differences did not reach statistical significance. For severe nomophobia, the rate for females was 76 (21.7%) and for males was 57 (18.8%) p = 0.9. For moderate-severe insomnia, the rate for females was 56 (16%) and for males was 36 (11.84%) p = 0.1. For food addiction, the rate for females was 71 (20.29%) and for males was 53 (17.43%) p = 0.3. A statistically significant association was present between nomophobia and insomnia r = 0.60, p < 0.001. No association was found between nomophobia and food addiction. Nomophobia is very common in young adults, particularly in females; nomophobia is associated with insomnia but not with food addiction.
Collapse
Affiliation(s)
- Haitham Jahrami
- Ministry of Health, Manama, Bahrain;
- College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain;
- Correspondence: (H.J.); (N.L.B.)
| | - Ammar Abdelaziz
- The Walton Centre, Neurology Department, Royal Liverpool University Hospital, NHS, Liverpool L9 7LJ, UK;
| | - Latifa Binsanad
- College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain;
| | - Omar A. Alhaj
- Department of Nutrition, Faculty of Pharmacy and Medical Science, University of Petra, Amman 11196, Jordan;
| | | | - Nicola Luigi Bragazzi
- Laboratory for Industrial and Applied Mathematics, Departments and Statistics, York University, Toronto, ON M3J 1P3, Canada
- Correspondence: (H.J.); (N.L.B.)
| | | | - Ahmed S. BaHammam
- Department of Medicine, College of Medicine, University Sleep Disorders Center, King Saud University, Box 225503, Riyadh 11324, Saudi Arabia;
- The Strategic Technologies Program of the National Plan for Sciences and Technology and Innovation in the Kingdom of Saudi Arabia, Riyadh 11324, Saudi Arabia
| | - Michael V. Vitiello
- Psychiatry & Behavioral Sciences, Gerontology & Geriatric Medicine, and Biobehavioral Nursing, University of Washington, Seattle, WA 98195-6560, USA;
| |
Collapse
|
32
|
Jahrami H, Rashed M, AlRasheed MM, Bragazzi NL, Saif Z, Alhaj O, BaHammam AS, Vitiello MV. Nomophobia is Associated with Insomnia but Not with Age, Sex, BMI, or Mobile Phone Screen Size in Young Adults. Nat Sci Sleep 2021; 13:1931-1941. [PMID: 34737661 PMCID: PMC8560167 DOI: 10.2147/nss.s335462] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/22/2021] [Indexed: 01/19/2023] Open
Abstract
PURPOSE NOMOPHOBIA (NO MObile PHone PhoBIA) or problematic smartphone use is a psychological disorder in which people are afraid of being cut off from their mobile phones. Currently, there has been no direct assessment of mobile phone screen size in the home setting and its effect on nomophobia and related symptoms, such as insomnia. Thus, we investigated the association between nomophobia, insomnia, and mobile phone screen size in a young adult population in Bahrain. PATIENTS AND METHODS Using a descriptive, cross-sectional design, we surveyed participants aged 18 to 35 between August and September 2020 using an online questionnaire. Participants completed demographic questions and questions about personal mobile phones, the Nomophobia Questionnaire (NMP-Q), and the Insomnia Severity Index (ISI). The mobile phone screen size was determined using an open-source online database. Crude and adjusted regression analyses were fitted to examine the associations between the study variables. RESULTS A total of 549 individuals, 54% females, were included in the final analyses. One hundred and fourteen participants (21%) had severe nomophobia, and 81 (14%) had clinical insomnia. A strong positive pair-wise linear association was observed between NMP-Q and ISI β 0.15, P = 0.001. Age, sex, BMI, and mobile phone screen size showed no association with the NMP-Q. CONCLUSION Nomophobia is very prevalent in young adult men and women, and it is closely associated with insomnia, regardless of mobile phone screen size, suggesting that mobile phone screen size should not be used as a proxy for hazardous usage.
Collapse
Affiliation(s)
- Haitham Jahrami
- Ministry of Health, Manama, Bahrain.,Department of Psychiatry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain
| | - Mona Rashed
- Ministry of Health, Manama, Bahrain.,Department of Psychiatry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain
| | - Maha M AlRasheed
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Nicola Luigi Bragazzi
- Department of Mathematics and Statistics, Laboratory for Industrial and Applied Mathematics (LIAM), York University, Toronto, ON, Canada
| | | | - Omar Alhaj
- Department of Nutrition, Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
| | - Ahmed S BaHammam
- Department of Medicine, College of Medicine, University Sleep Disorders Center, King Saud University, Riyadh, 11324, Saudi Arabia.,The Strategic Technologies Program of the National Plan for Sciences and Technology and Innovation in the Kingdom of Saudi Arabia, Riyadh, Saudi Arabia
| | - Michael V Vitiello
- Psychiatry & Behavioral Sciences, Gerontology & Geriatric Medicine, and Biobehavioral Nursing, University of Washington, Seattle, WA, 98195-6560, USA
| |
Collapse
|
33
|
Kossowski B, Droździel D, Rode K, Michałowski J, Jankowski KS, Wypych M, Wolska A, Marchewka A. The influence of light exposure and chronotype on working memory in humans. Acta Neurobiol Exp (Wars) 2021. [DOI: 10.21307/ane-2021-011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
34
|
Killgore WDS. Lightening the mood: evidence for blue light exposure in the treatment of post-concussion depression. Expert Rev Neurother 2020; 20:1081-1083. [PMID: 32865054 DOI: 10.1080/14737175.2020.1814147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- William D S Killgore
- Department of Psychiatry, University of Arizona College of Medicine , Tucson, AZ, USA
| |
Collapse
|
35
|
Blue light exposure enhances neural efficiency of the task positive network during a cognitive interference task. Neurosci Lett 2020; 735:135242. [PMID: 32652208 DOI: 10.1016/j.neulet.2020.135242] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 01/01/2023]
Abstract
Exposure to light, particularly blue-wavelength light, has been shown to acutely increase brain activation, alertness, and some elementary aspects of cognitive performance such as working memory and emotional anticipation. Whether blue light exposure can have effects on brain activation and performance during more complex cognitive control tasks up to 30 min after light cessation is unknown. In a sample of 32 healthy adults, we examined the effects of a 30 min exposure to either blue (n = 16) or amber control (n = 16) light on subsequent brain activation and performance during the Multi-Source Interference Task (MSIT) measured a half-hour after light exposure. Performance on the MSIT did not differ between the blue and amber conditions. However, brain activation within the task positive network (TPN) to the interference condition was significantly lower in the blue relative to the amber condition, while no group differences were observed for suppression of the default mode network (DMN). These findings suggest that, compared to control, a single exposure to blue light was associated with enhanced neural efficiency, as demonstrated by reduced TPN activation to achieve the same level of performance. Blue light may be an effective method for optimizing neurocognitive performance under some conditions.
Collapse
|
36
|
Domagalik A, Oginska H, Beldzik E, Fafrowicz M, Pokrywka M, Chaniecki P, Rekas M, Marek T. Long-Term Reduction of Short-Wavelength Light Affects Sustained Attention and Visuospatial Working Memory With No Evidence for a Change in Circadian Rhythmicity. Front Neurosci 2020; 14:654. [PMID: 32719581 PMCID: PMC7348134 DOI: 10.3389/fnins.2020.00654] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 05/27/2020] [Indexed: 01/01/2023] Open
Abstract
The short wavelength, i.e., blue light, is crucial for non-image forming effects such as entrainment of the circadian system in humans. Moreover, many studies showed that blue light enhances alertness and performance in cognitive tasks. However, most scientific reports in this topic are based on experiments using short exposure to blue or blue-enriched light, and only a few focused on the effects of its reduced transmittance, especially in longer periods. The latter could potentially give insight into understanding if age-related sleep problems and cognitive decline are related to less amount of blue light reaching the retina, as the eyes' lenses yellow with age. In this study, we investigated the effects of prolonged blocking of blue light on cognitive functioning, in particular-sustained attention and visuospatial working memory, as well as on sleep, and melatonin and cortisol levels. A group of young, healthy participants was randomly allocated to either blue light blocking or control group. Depending on the group, participants wore amber contact lenses, reducing the transmittance of blue light by ∼90% or regular contact lenses for a period of 4 weeks. No changes were observed for measurements related to sleep and sleep-wake rhythm. Dim light melatonin onset, evening levels of melatonin, and morning cortisol answer did not show any significant alterations during blue light (BL) blockade. The significant effects were revealed both for sustained attention and visuospatial memory, i.e., the longer blocking the blue light lasted, the greater decrease in performance observed. Additionally, the follow-up session conducted ∼1 week after taking off the blue-blocking lenses revealed that in case of sustained attention, this detrimental effect of blocking BL is fully reversible. Our findings provide evidence that prolonged reduction of BL exposure directly affects human cognitive functioning regardless of circadian rhythmicity.
Collapse
Affiliation(s)
- Aleksandra Domagalik
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Halszka Oginska
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
| | - Ewa Beldzik
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
| | - Magdalena Fafrowicz
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
| | - Malgorzata Pokrywka
- Department of Clinical Biochemistry, Jagiellonian University Medical College, Kraków, Poland
| | | | - Marek Rekas
- Ophthalmology Department, Military Institute of Medicine, Warsaw, Poland
| | - Tadeusz Marek
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
| |
Collapse
|
37
|
Effects of Different Light Sources on Neural Activity of the Paraventricular Nucleus in the Hypothalamus. ACTA ACUST UNITED AC 2019; 55:medicina55110732. [PMID: 31717519 PMCID: PMC6915334 DOI: 10.3390/medicina55110732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/30/2019] [Accepted: 11/06/2019] [Indexed: 12/03/2022]
Abstract
Background and Objectives: Physical function is influenced by light irradiation, and interest in the influence of light irradiation on health is high. Light signals are transmitted from the retina to the suprachiasmatic nucleus (SCN) via the retinal hypothalamic tract as non-image vision. Additionally, the SCN projects a nerve to the paraventricular nucleus (PVN) which acts as a stress center. This study examined the influences of three different light sources on neural activity in the PVN region using two different color temperatures. Materials and Methods: Experiments were conducted using twenty-eight Institute of Cancer Research (ICR) mice (10 week old males). Three light sources were used: (1) organic light-emitting diode (OLED) lighting, (2) LED lighting, and (3) fluorescent lighting. We examined the effects of light irradiation from the three light sources using two different color temperatures (2800 K and 4000 K). Perfusion was done 60 min after light irradiation, and then the brain was removed from the mouse for an immunohistochemistry analysis. c-Fos was immunohistochemically visualized as a marker of neural activity in the PVN region. Results: The number of c-Fos-positive cells was found to be significantly lower under OLED lighting and LED lighting conditions than under fluorescent lighting at a color temperature of 2800 K, and significantly lower under OLED lighting than LED lighting conditions at a color temperature of 4000 K. Conclusions: This study reveals that different light sources and color temperatures alter the neural activity of the PVN region. These results suggest that differences in the light source or color temperature may affect the stress response.
Collapse
|
38
|
Chai MT, Amin HU, Izhar LI, Saad MNM, Abdul Rahman M, Malik AS, Tang TB. Exploring EEG Effective Connectivity Network in Estimating Influence of Color on Emotion and Memory. Front Neuroinform 2019; 13:66. [PMID: 31649522 PMCID: PMC6794354 DOI: 10.3389/fninf.2019.00066] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/18/2019] [Indexed: 11/20/2022] Open
Abstract
Color is a perceptual stimulus that has a significant impact on improving human emotion and memory. Studies have revealed that colored multimedia learning materials (MLMs) have a positive effect on learner's emotion and learning where it was assessed by subjective/objective measurements. This study aimed to quantitatively assess the influence of colored MLMs on emotion, cognitive processes during learning, and long-term memory (LTM) retention using electroencephalography (EEG). The dataset consisted of 45 healthy participants, and MLMs were designed in colored or achromatic illustrations to elicit emotion and that to assess its impact on LTM retention after 30-min and 1-month delay. The EEG signal analysis was first started to estimate the effective connectivity network (ECN) using the phase slope index and expand it to characterize the ECN pattern using graph theoretical analysis. EEG results showed that colored MLMs had influences on theta and alpha networks, including (1) an increased frontal-parietal connectivity (top-down processing), (2) a larger number of brain hubs, (3) a lower clustering coefficient, and (4) a higher local efficiency, indicating that color influences information processing in the brain, as reflected by ECN, together with a significant improvement in learner's emotion and memory performance. This is evidenced by a more positive emotional valence and higher recall accuracy for groups who learned with colored MLMs than that of achromatic MLMs. In conclusion, this paper demonstrated how the EEG ECN parameters could help quantify the influences of colored MLMs on emotion and cognitive processes during learning.
Collapse
Affiliation(s)
- Meei Tyng Chai
- Centre for Intelligent Signal and Imaging Research, Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Hafeez Ullah Amin
- Centre for Intelligent Signal and Imaging Research, Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Lila Iznita Izhar
- Centre for Intelligent Signal and Imaging Research, Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Mohamad Naufal Mohamad Saad
- Centre for Intelligent Signal and Imaging Research, Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Mohammad Abdul Rahman
- Faculty of Medicine, Royal College of Medicine Perak, Universiti Kuala Lumpur, Ipoh, Malaysia
| | | | - Tong Boon Tang
- Centre for Intelligent Signal and Imaging Research, Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| |
Collapse
|
39
|
Wong LR, Flynn-Evans E, Ruskin KJ. Fatigue Risk Management: The Impact of Anesthesiology Residents' Work Schedules on Job Performance and a Review of Potential Countermeasures. Anesth Analg 2019; 126:1340-1348. [PMID: 29049076 DOI: 10.1213/ane.0000000000002548] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Long duty periods and overnight call shifts impair physicians' performance on measures of vigilance, psychomotor functioning, alertness, and mood. Anesthesiology residents typically work between 64 and 70 hours per week and are often required to work 24 hours or overnight shifts, sometimes taking call every third night. Mitigating the effects of sleep loss, circadian misalignment, and sleep inertia requires an understanding of the relationship among work schedules, fatigue, and job performance. This article reviews the current Accreditation Council for Graduate Medical Education guidelines for resident duty hours, examines how anesthesiologists' work schedules can affect job performance, and discusses the ramifications of overnight and prolonged duty hours on patient safety and resident well-being. We then propose countermeasures that have been implemented to mitigate the effects of fatigue and describe how training programs or practice groups who must work overnight can adapt these strategies for use in a hospital setting. Countermeasures include the use of scheduling interventions, strategic naps, microbreaks, caffeine use during overnight and extended shifts, and the use of bright lights in the clinical setting when possible or personal blue light devices when the room lights must be turned off. Although this review focuses primarily on anesthesiology residents in training, many of the mitigation strategies described here can be used effectively by physicians in practice.
Collapse
Affiliation(s)
- Lily R Wong
- From the San Jose State University Research Foundation, San Jose, California.,Human Factors Research Division, NASA Ames Research Center, Moffett Field, California
| | - Erin Flynn-Evans
- Human Factors Research Division, NASA Ames Research Center, Moffett Field, California
| | - Keith J Ruskin
- Department of Anesthesia and Critical Care, University of Chicago School of Medicine, Chicago, Illinois
| |
Collapse
|
40
|
Tonetti L, Natale V. Effects of a single short exposure to blue light on cognitive performance. Chronobiol Int 2019; 36:725-732. [PMID: 30897969 DOI: 10.1080/07420528.2019.1593191] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The aim of the present study is to explore the effects of a single short one-minute exposure to blue light on cognitive performance. For this purpose, 32 young adults (16 females, mean age 24.06 ± 1.88 years) took part in a within-subjects research design, under two conditions: blue light and no light. Under both conditions, they performed the lexical decision task (LDT) in order to assess the degree of automatic activation of semantic memory through an embedded semantic priming (reaction times to prime - reaction times to target), together with the Attention Network Test (ANT) to assess the efficiency of the alerting, executive and orienting networks. During the LDT, a significantly stronger semantic priming under the blue light condition compared to no light was observed, while during the ANT a significant difference in orienting network efficiency between conditions was observed. The present data appear to highlight that even a single short exposure to blue light has an effect on cognitive performance in young adults.
Collapse
Affiliation(s)
- Lorenzo Tonetti
- a Department of Psychology , University of Bologna , Bologna , Italy
| | - Vincenzo Natale
- a Department of Psychology , University of Bologna , Bologna , Italy
| |
Collapse
|
41
|
Abstract
Dynamic vision is crucial to not only animals’ hunting behaviors but also human activities, and yet little is known about how to enhance it, except for extensive trainings like athletics do. Exposure to blue light has been shown to enhance human alertness (Chellappa et al., 2011), perhaps through intrinsically photosensitive retinal ganglion cells (ipRGCs), which are sensitive to motion perception as revealed by animal studies. However, it remains unknown whether blue light can enhance human dynamic vision, a motion-related ability. We conducted five experiments under blue or orange light to test three important components of dynamic vision: eye pursuit accuracy (EPA, Experiment 1), kinetic visual acuity (KVA, Experiment 1 and 2), and dynamic visual acuity (DVA, Experiment 3–5). EPA was measured by the distance between the position of the fixation and the position of the target when participants tracked a target dot. In the KVA task, participants reported three central target numbers (randomly chosen from 0 to 9) moving toward participants in the depth plane, with speed threshold calculated by a staircase procedure. In the DVA task, three numbers were presented along the meridian line on the same depth plane, with motion direction (Experiment 3) and difficulty level (Experiment 4) manipulated, and a blue light filter lens was used to test the ipRGCs contribution (Experiment 5). Results showed that blue light enhanced EPA and DVA, but reduced KVA. Further, DVA enhancement was modulated by difficulty level: blue light enhancement effect was found only with hard task in the downward motion in Experiment 3 and with the low contrast target in Experiment 4. However, this blue light enhancement effect was not caused by mechanism of the ipRGCs, at least not in the range we tested. In this first study demonstrating the relationship between different components of dynamic vision and blue light, our findings that DVA can be enhanced under blue light with hard but not easy task indicate that blue light can enhance dynamic visual discrimination when needed.
Collapse
Affiliation(s)
- Hung-Wen Chen
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Su-Ling Yeh
- Department of Psychology, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan.,Center for Artificial Intelligence and Advanced Robotics, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
42
|
Changes in morning salivary melatonin correlate with prefrontal responses during working memory performance. Neuroreport 2019. [PMID: 29528974 DOI: 10.1097/wnr.0000000000001002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Humans demonstrate a circadian rhythm of melatonin production that closely tracks the daily light/dark cycle, with profound increases in circulating levels during the night-time and nearly nonexistent levels during daylight hours. Although melatonin is known to play a role in preparing the brain and body for sleep, its effects on cognition and brain function are not well understood. We hypothesized that declines in morning melatonin would be associated with increased functional activation within cortical regions involved in alertness, attention, and executive function. We measured the change in salivary melatonin from mid-morning to late-morning in 26 healthy young adults who were also exposed to a 30-min period of blue or amber light followed by functional MRI during a working memory task (N-back). Brain activation was regressed on the change in melatonin scores from the mid-morning to late-morning saliva samples and the role of light exposure was also assessed. Although overall melatonin levels did not change significantly over the morning at the group level, individual declines in salivary melatonin were associated with significant increases in activation within the left dorsomedial and right inferior lateral prefrontal cortex during the 2-back condition (P<0.05, cluster corrected). Medial prefrontal activation also correlated modestly with better vigilance performance during the 0-back (P<0.05), but not the 1-back or 2-back conditions. The light condition did not affect the outcomes. These findings suggest declining melatonin levels in the morning are associated with increased prefrontal cortex functioning and may play a role in the increased frontal activation that occurs following awakening.
Collapse
|
43
|
Raikes AC, Killgore WDS. Potential for the development of light therapies in mild traumatic brain injury. Concussion 2018; 3:CNC57. [PMID: 30370058 PMCID: PMC6199671 DOI: 10.2217/cnc-2018-0006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/01/2018] [Indexed: 12/12/2022] Open
Abstract
Light affects almost all aspects of human physiological functioning, including circadian rhythms, sleep-wake regulation, alertness, cognition and mood. We review the existing relevant literature on the effects of various wavelengths of light on these major domains, particularly as they pertain to recovery from mild traumatic brain injuries. Evidence suggests that light, particularly in the blue wavelengths, has powerful alerting, cognitive and circadian phase shifting properties that could be useful for treatment. Other wavelengths, such as red and green may also have important effects that, if targeted appropriately, might also be useful for facilitating recovery. Despite the known effects of light, more research is needed. We recommend a personalized medicine approach to the use of light therapy as an adjunctive treatment for patients recovering from mild traumatic brain injury.
Collapse
Affiliation(s)
- Adam C Raikes
- Social, Cognitive & Affective Neuroscience Lab, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, USA
- ORCID: 0000-0002-1609-6727
| | - William DS Killgore
- Social, Cognitive & Affective Neuroscience Lab, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, USA
- ORCID: 0000-0002-5328-0208
| |
Collapse
|
44
|
Xu Q, Lang CP. Revisiting the alerting effect of light: A systematic review. Sleep Med Rev 2018; 41:39-49. [PMID: 29398582 DOI: 10.1016/j.smrv.2017.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 11/28/2017] [Accepted: 12/01/2017] [Indexed: 01/06/2023]
Abstract
Light plays an essential role in maintaining alertness levels. Like other non-image-forming responses, the alerting effect of light is influenced by its spectral wavelength, duration and intensity. Alertness levels are also dependent on circadian rhythm (process C) and homeostatic sleep pressure (process S), consistent with the classic two-process model of sleep regulation. Over the last decade, there has been increasing recognition of an additional process (referred to as the third process) in sleep regulation. This third process seems to receive sensory inputs from body systems such as digestion, and is usually synchronised with process C and process S. Previous studies on the alerting effect of light have been mostly conducted in laboratories. Although these studies are helpful in delineating the impact of process C and process S, their ability to assist in understanding the third process is limited. This systematic review investigated the factors that influence the alerting effect of light by examining randomised controlled trials and randomised or counterbalanced crossover studies. Factors that influence light's alerting effect were examined with reference to the three-process model. The post-illuminance alerting effect was examined separately due to its potential to offer flexible workplace-based light interventions to increase or maintain employees' alertness.
Collapse
Affiliation(s)
- Qunyan Xu
- School of Nursing and Midwifery, University of South Australia, Australia.
| | - Cathryne P Lang
- School of Psychology, Australian Catholic University, Australia
| |
Collapse
|
45
|
Bauer M, Glenn T, Monteith S, Gottlieb JF, Ritter PS, Geddes J, Whybrow PC. The potential influence of LED lighting on mental illness. World J Biol Psychiatry 2018; 19:59-73. [PMID: 29251065 DOI: 10.1080/15622975.2017.1417639] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES Two recent scientific breakthroughs may alter the treatment of mental illness, as discussed in this narrative review. The first was the invention of white light-emitting diodes (LEDs), which enabled an ongoing, rapid transition to energy-efficient LEDs for lighting, and the use of LEDs to backlight digital devices. The second was the discovery of melanopsin-expressing photosensitive retinal ganglion cells, which detect environmental irradiance and mediate non-image forming (NIF) functions including circadian entrainment, melatonin secretion, alertness, sleep regulation and the pupillary light reflex. These two breakthroughs are interrelated because unlike conventional lighting, white LEDs have a dominant spectral wavelength in the blue light range, near the peak sensitivity for the melanopsin system. METHODS Pertinent articles were identified. RESULTS Blue light exposure may suppress melatonin, increase alertness, and interfere with sleep in young, healthy volunteers and in animals. Areas of concern in mental illness include the influence of blue light on sleep, other circadian-mediated symptoms, prescribed treatments that target the circadian system, measurement using digital apps and devices, and adolescent sensitivity to blue light. CONCLUSIONS While knowledge in both fields is expanding rapidly, future developments must address the potential impact of blue light on NIF functions for healthy individuals and those with mental illness.
Collapse
Affiliation(s)
- Michael Bauer
- a Department of Psychiatry and Psychotherapy , University Hospital Carl Gustav Carus, Medical Faculty, Technische Universität Dresden , Dresden , Germany
| | - Tasha Glenn
- b ChronoRecord Association, Inc , Fullerton , CA , USA
| | - Scott Monteith
- c Michigan State University College of Human Medicine, Traverse City Campus , Traverse City , MI , USA
| | - John F Gottlieb
- d Department of Psychiatry , Feinberg School of Medicine, Northwestern University , Chicago , IL , USA
| | - Philipp S Ritter
- a Department of Psychiatry and Psychotherapy , University Hospital Carl Gustav Carus, Medical Faculty, Technische Universität Dresden , Dresden , Germany
| | - John Geddes
- e Department of Psychiatry , University of Oxford, Warneford Hospital , Oxford , UK
| | - Peter C Whybrow
- f Department of Psychiatry and Biobehavioral Sciences , Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles (UCLA) , Los Angeles , CA , USA
| |
Collapse
|
46
|
Satterfield BC, Raikes AC, Killgore WDS. Rested-Baseline Responsivity of the Ventral Striatum Is Associated With Caloric and Macronutrient Intake During One Night of Sleep Deprivation. Front Psychiatry 2018; 9:749. [PMID: 30705642 PMCID: PMC6344438 DOI: 10.3389/fpsyt.2018.00749] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/19/2018] [Indexed: 01/24/2023] Open
Abstract
Background: Sleep loss contributes to obesity through a variety of mechanisms, including neuroendocrine functioning, increased hunger, and increased food intake. Additionally, sleep loss alters functional activation within brain regions associated with reward and behavioral control. However, it remains unknown whether individual differences in baseline neural functioning can predict eating behaviors during total sleep deprivation (TSD). We used functional magnetic resonance imaging (fMRI) to test the hypothesis that individuals with increased baseline responsiveness within reward regions are more vulnerable to TSD-induced overeating. Methods: N = 45 subjects completed several fMRI scans during a single pre-TSD session that included performance on the Multi-Source Interference Task (MSIT) and the n-back task. Subjects returned to the laboratory for an overnight TSD session, during which they were given ad libitum access to 10,900 kcal of food. Leftover food and packaging were collected every 6 h (00:00, 06:00, and 12:00) to measure total food consumption. Subjects reported sleepiness every hour and performed a food rating task every 3 h. Results: Functional activation within the ventral striatum during the MSIT and n-back positively correlated with total caloric and carbohydrate intake during the final 6 h (06:00-12:00) of TSD. Activation within the middle and superior temporal gyri during the MSIT also correlated with total carbohydrates consumed. Food consumption did not correlate with subjective sleepiness, hunger, or food desire. Conclusions: Individual differences in neural activity of reward processing areas (i.e., nucleus accumbens) prior to sleep deprivation are associated with an individual's propensity to overeat during subsequent sleep deprivation. This suggests that individual differences within reward processing pathways are potential key factors in sleep loss related overeating. Sleep loss and obesity are tightly linked. Both phenomena have been associated with increased neural activation in regions associated with reward, inhibitory control, and disrupted dopamine signaling. Elevated baseline reward sensitivity in the ventral striatum appears to be further compounded by sleep deprivation induced dysfunction in the reward neurocircuitry, increasing the likelihood of overeating. Our findings suggest that large individual differences in baseline responsiveness of hedonic reward pathways may modulate the association between sleep loss and obesity.
Collapse
Affiliation(s)
- Brieann C Satterfield
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Adam C Raikes
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - William D S Killgore
- Social, Cognitive, and Affective Neuroscience Laboratory, Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States.,Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States
| |
Collapse
|
47
|
Bajaj S, Vanuk JR, Smith R, Dailey NS, Killgore WDS. Blue-Light Therapy following Mild Traumatic Brain Injury: Effects on White Matter Water Diffusion in the Brain. Front Neurol 2017; 8:616. [PMID: 29213254 PMCID: PMC5702646 DOI: 10.3389/fneur.2017.00616] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 11/06/2017] [Indexed: 11/13/2022] Open
Abstract
Mild traumatic brain injury (mTBI) is a common and often inconspicuous wound that is frequently associated with chronic low-grade symptoms and cognitive dysfunction. Previous evidence suggests that daily blue wavelength light therapy may be effective at reducing fatigue and improving sleep in patients recovering from mTBI. However, the effects of light therapy on recovering brain structure remain unexplored. In this study, we analyzed white matter diffusion properties, including generalized fractional anisotropy, and the quantity of water diffusion in isotropic (i.e., isotropic diffusion) and anisotropic fashion (i.e., quantitative anisotropy, QA) for fibers crossing 11 brain areas known to be significantly affected following mTBI. Specifically, we investigated how 6 weeks of daily morning blue light exposure therapy (compared to an amber-light placebo condition) impacted changes in white matter diffusion in individuals with mTBI. We observed a significant impact of the blue light treatment (relative to the placebo) on the amount of water diffusion (QA) for multiple brain areas, including the corpus callosum, anterior corona radiata, and thalamus. Moreover, many of these changes were associated with improvements in sleep latency and delayed memory. These findings suggest that blue wavelength light exposure may serve as one of the potential non-pharmacological treatments for facilitating structural and functional recovery following mTBI; they also support the use of QA as a reliable neuro-biomarker for mTBI therapies.
Collapse
Affiliation(s)
- Sahil Bajaj
- Social, Cognitive and Affective Neuroscience Laboratory (SCAN Lab), Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - John R Vanuk
- Social, Cognitive and Affective Neuroscience Laboratory (SCAN Lab), Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Ryan Smith
- Social, Cognitive and Affective Neuroscience Laboratory (SCAN Lab), Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Natalie S Dailey
- Social, Cognitive and Affective Neuroscience Laboratory (SCAN Lab), Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| | - William D S Killgore
- Social, Cognitive and Affective Neuroscience Laboratory (SCAN Lab), Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
48
|
Alkozei A, Smith R, Dailey NS, Bajaj S, Killgore WDS. Acute exposure to blue wavelength light during memory consolidation improves verbal memory performance. PLoS One 2017; 12:e0184884. [PMID: 28922397 PMCID: PMC5602660 DOI: 10.1371/journal.pone.0184884] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/03/2017] [Indexed: 12/22/2022] Open
Abstract
Acute exposure to light within the blue wavelengths has been shown to enhance alertness and vigilance, and lead to improved speed on reaction time tasks, possibly due to activation of the noradrenergic system. It remains unclear, however, whether the effects of blue light extend beyond simple alertness processes to also enhance other aspects of cognition, such as memory performance. The aim of this study was to investigate the effects of a thirty minute pulse of blue light versus placebo (amber light) exposure in healthy normally rested individuals in the morning during verbal memory consolidation (i.e., 1.5 hours after memory acquisition) using an abbreviated version of the California Verbal Learning Test (CVLT-II). At delayed recall, individuals who received blue light (n = 12) during the consolidation period showed significantly better long-delay verbal recall than individuals who received amber light exposure (n = 18), while controlling for the effects of general intelligence, depressive symptoms and habitual wake time. These findings extend previous work demonstrating the effect of blue light on brain activation and alertness to further demonstrate its effectiveness at facilitating better memory consolidation and subsequent retention of verbal material. Although preliminary, these findings point to a potential application of blue wavelength light to optimize memory performance in healthy populations. It remains to be determined whether blue light exposure may also enhance performance in clinical populations with memory deficits.
Collapse
Affiliation(s)
- Anna Alkozei
- Department of Psychiatry, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - Ryan Smith
- Department of Psychiatry, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - Natalie S. Dailey
- Department of Psychiatry, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - Sahil Bajaj
- Department of Psychiatry, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - William D. S. Killgore
- Department of Psychiatry, University of Arizona College of Medicine, Tucson, Arizona, United States of America
- * E-mail:
| |
Collapse
|