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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.
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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
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Desmettre T, Baillif S, Mathis T, Gatinel D, Mainster M. [Blue light and intraocular lenses (IOLs): Beliefs and realities]. J Fr Ophtalmol 2024; 47:104043. [PMID: 38241770 DOI: 10.1016/j.jfo.2023.104043] [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: 09/26/2023] [Revised: 10/18/2023] [Accepted: 10/22/2023] [Indexed: 01/21/2024]
Abstract
The first intraocular lenses (IOLs) used for cataract surgery transmitted both ultraviolet (UV) radiation and visible light to the retina. Colorless UV-blocking IOLs were introduced and rapidly adopted in the 1980s. Yellow-tinted blue-blocking (also known as blue-filtering) IOLs were marketed in the early 1990s. Blue-blocking IOLs were intended to simulate age-related crystalline lens yellowing to reduce the cyanopsia that some patients experienced after cataract surgery. When blue-filtering IOLs were introduced in North America, however, blue-blocking chromophores were advocated as a way to protect patients from age-related macular degeneration (AMD) despite the lack of evidence that normal environmental light exposure causes AMD. The "blue light hazard" is a term that describes the experimental finding that acute, abnormally intense light exposures are potentially more phototoxic to the retina when short rather than long wavelengths are used. Thus, in brief exposures to intense light sources such as welding arcs, ultraviolet radiation is more hazardous than blue light, which is more hazardous than longer wavelength green or red light. International commissions have cautioned that the blue light hazard does not apply to normal indoor or outdoor light exposures. Nonetheless, the hazard is used for commercial purposes to suggest misleadingly that ambient environmental light can cause acute retinal phototoxicity and increase the risk of AMD. Very large epidemiological studies show that blue-blocking IOLs do not reduce the risk or progression of AMD. Additionally, blue-filtering IOLs or spectacles cannot decrease glare disability, because they decrease image and glare illuminance in the same proportion. Blue light is essential for older adults' scotopic photoreception needed to reduce the risk of nighttime falling and related injuries. It is also critical for circadian photoreception that is essential for good health, sleep and cognitive performance. Unfortunately, age-related pupillary miosis, retinal rod and ganglion cell photoreceptor degeneration and decreased outdoor activity all reduce the amount of healthful blue light available to older adults. Blue-restricting IOLs further reduce the available blue light at a time when older adults need it most. Patients and ophthalmologists are exposed to hypothesis-based advertisements for blue-filtering optical devices that suppress short wavelength light critical for vision in dim lighting and for good physical and mental health. Spectacle and intraocular lens selections should be based on scientific fact, not conjecture. Ideal IOLs should improve photoreception rather than limit it permanently. Practice efficiency, surgical convenience and physician-manufacturer relationships may eliminate a patient's opportunity to choose between colorless blue-transmitting IOLs and yellow-tinted, blue-restricting IOLs. Cataract surgeons ultimately determine whether their patients have the opportunity to make an informed choice about their future photoreception.
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Affiliation(s)
- T Desmettre
- Centre de rétine médicale, 187, rue de Menin, 59520 Marquette-Lez-Lille, France.
| | - S Baillif
- Département d'ophtalmologie, hôpital Pasteur, 30, voie Romaine, 06000 Nice cedex 1, France
| | - T Mathis
- Service d'ophtalmologie, hôpital de la Croix-Rousse, hospices civils de Lyon, 69004 Lyon, France
| | - D Gatinel
- Service d'ophtalmologie, fondation A.-de-Rothschild, 25, rue Manin, 75940 Paris cedex 19, France
| | - M Mainster
- Department of Ophthalmology, University of Kansas School of Medicine, Prairie Village, Kansas, États-Unis
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Flynn-Evans EE, Rueger M, Liu AM, Galvan-Garza RC, Natapoff A, Oman CM, Lockley SW. Effectiveness of caffeine and blue-enriched light on cognitive performance and electroencephalography correlates of alertness in a spaceflight robotics simulation. NPJ Microgravity 2023; 9:93. [PMID: 38114500 PMCID: PMC10730879 DOI: 10.1038/s41526-023-00332-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 10/25/2023] [Indexed: 12/21/2023] Open
Abstract
Human cognitive impairment associated with sleep loss, circadian misalignment and work overload is a major concern in any high stress occupation but has potentially catastrophic consequences during spaceflight human robotic interactions. Two safe, wake-promoting countermeasures, caffeine and blue-enriched white light have been studied on Earth and are available on the International Space Station. We therefore conducted a randomized, placebo-controlled, cross-over trial examining the impact of regularly timed low-dose caffeine (0.3 mg per kg per h) and moderate illuminance blue-enriched white light (~90 lux, ~88 melEDI lux, 6300 K) as countermeasures, separately and combined, in a multi-night simulation of sleep-wake shifts experienced during spaceflight among 16 participants (7 F, ages 26-55). We find that chronic administration of low-dose caffeine improves subjective and objective correlates of alertness and performance during an overnight work schedule involving chronic sleep loss and circadian misalignment, although we also find that caffeine disrupts subsequent sleep. We further find that 90 lux of blue-enriched light moderately reduces electroencephalogram (EEG) power in the theta and delta regions, which are associated with sleepiness. These findings support the use of low-dose caffeine and potentially blue-enriched white light to enhance alertness and performance among astronauts and shiftworking populations.
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Affiliation(s)
- Erin E Flynn-Evans
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, 02115, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, 02115, Boston, MA, USA
- Fatigue Countermeasures Laboratory, Human Systems Integration Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Melanie Rueger
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, 02115, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, 02115, Boston, MA, USA
| | - Andrew M Liu
- Human Systems Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Raquel C Galvan-Garza
- Human Systems Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Alan Natapoff
- Human Systems Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Charles M Oman
- Human Systems Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Steven W Lockley
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, 02115, Boston, MA, USA.
- Division of Sleep Medicine, Harvard Medical School, 02115, Boston, MA, USA.
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4
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Espinosa Rodríguez G, Arboleya JC, Prado D, Munk R, Rodríguez Valerón N. Bioluminescence experience in the holistic cuisine: Making contact through living light and sound. Int J Gastron Food Sci 2022. [DOI: 10.1016/j.ijgfs.2022.100641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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5
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Ai Y, Pei H. Effects of time pressure on tourists' sensory consumption via the mediating role of salient motivation. J SENS STUD 2022. [DOI: 10.1111/joss.12801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yijie Ai
- School of Business Administration Shandong Management University Jinan China
| | - Hongzhou Pei
- College of Business Administration Shanghai Business School Shanghai China
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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: 19] [Impact Index Per Article: 9.5] [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.
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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,
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Sabbah S, Worden MS, Laniado DD, Berson DM, Sanes JN. 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: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 05/16/2022] [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.
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Affiliation(s)
- Shai Sabbah
- Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Michael S. Worden
- Department of Neuroscience, Brown University, Providence, RI 02912
- Carney Institute for Brain Science, Brown University, Providence, RI 02912
| | - Dimitrios D. Laniado
- Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - David M. Berson
- Department of Neuroscience, Brown University, Providence, RI 02912
- Carney Institute for Brain Science, Brown University, Providence, RI 02912
| | - Jerome N. Sanes
- Department of Neuroscience, Brown University, Providence, RI 02912
- Carney Institute for Brain Science, Brown University, Providence, RI 02912
- Center for Neurorestoration and Neurotechnology, Veterans Affairs Providence Healthcare System, Providence, RI 02908
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Xia D, Yang L, Cui J, Li Y, Jiang X, Meca G, Wang S, Feng Y, Zhao Y, Qin J, Zhu Y, Ye H, Wang W. Combined Analysis of the Effects of Exposure to Blue Light in Ducks Reveals a Reduction in Cholesterol Accumulation Through Changes in Methionine Metabolism and the Intestinal Microbiota. Front Nutr 2021; 8:737059. [PMID: 34901103 PMCID: PMC8656972 DOI: 10.3389/fnut.2021.737059] [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: 07/06/2021] [Accepted: 10/18/2021] [Indexed: 11/21/2022] Open
Abstract
Monochromatic light is widely used in industry, medical treatment, and animal husbandry. Green-blue light has been found to stimulate the proliferation of satellite cells and the results of studies on the effects of blue light on poultry vary widely. It would be worthwhile to study the effect of blue light on poultry growth and how exposure to blue light affects metabolism and the intestinal microbiota. In this study, we irradiated Cherry Valley ducks with 460 nm wavelength light (blue light) for 3 weeks to explore the effects of blue light in comparison to those of white light (combined wavelength light) on animal growth and development. Our results showed that, under exposure to blue light, the body weight and average daily feed intake of ducks were decreased, but the leg muscle and relative length of the intestine were increased. Exposure to blue light chiefly enhanced the anti-inflammatory and antioxidant capacities of the animal and decreased lipid levels in serum and liver. Metabolomic analysis revealed that blue light heightened cysteine and methionine metabolism, and increased serum taurine and primary bile acid levels, as well as up-regulating the metabolites L-carnitine and glutamine. Treatment with blue light significantly increased the beta diversity of intestinal microbiota and the relative abundances of bile acid hydrolase-producing bacteria, especially Alistipes. These changes promote the synthesis of secondary bile acids to further enhance lipid metabolism in the host, thereby reducing cholesterol accumulation in ducks. These results should help us better understand the effects of exposure to blue light on metabolite levels and the intestinal microbiota, and suggest that it may be possible to use colored light to control the development of livestock and poultry.
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Affiliation(s)
- Daiyang Xia
- Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Lin Yang
- Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Jiajie Cui
- Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Yu Li
- Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Xianzhi Jiang
- Microbiome Research Center, Moon (Guangzhou) Biotech Co. Ltd., Guangzhou, China
| | - Giuseppe Meca
- Laboratory of Food Chemistry and Toxicology, Faculty of Pharmacy, University of Valencia, Valencia, Spain
| | | | - Yan Feng
- Guangdong Haida Group Co. Ltd., Guangzhou, China
| | - Yujie Zhao
- Gold Coin Feedmill (Dong Guan) Co. Ltd., Dongguan, China
| | | | - Yongwen Zhu
- Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Hui Ye
- Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Wence Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
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Sobczak AM, Bohaterewicz B, Fafrowicz M, Domagalik A, Beldzik E, Oginska H, Golonka N, Rekas M, Bronicki D, Romanowska-Dixon B, Bolsega-Pacud J, Karwowski W, Farahani FV, Marek T. The Influence of Intraocular Lens Implantation and Alterations in Blue Light Transmittance Level on the Brain Functional Network Architecture Reorganization in Cataract Patients. Brain Sci 2021; 11:brainsci11111400. [PMID: 34827400 PMCID: PMC8615544 DOI: 10.3390/brainsci11111400] [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: 07/21/2021] [Revised: 10/16/2021] [Accepted: 10/19/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Cataract is one of the most common age-related vision deteriorations, leading to opacification of the lens and therefore visual impairment as well as blindness. Both cataract extraction and the implantation of blue light filtering lens are believed to improve not only vision but also overall functioning. METHODS Thirty-four cataract patients were subject to resting-state functional magnetic resonance imaging before and after cataract extraction and intraocular lens implantation (IOL). Global and local graph metrics were calculated in order to investigate the reorganization of functional network architecture associated with alterations in blue light transmittance. Psychomotor vigilance task (PVT) was conducted. RESULTS Graph theory-based analysis revealed decreased eigenvector centrality after the cataract extraction and IOL replacement in inferior occipital gyrus, superior parietal gyrus and many cerebellum regions as well as increased clustering coefficient in superior and inferior parietal gyrus, middle temporal gyrus and various cerebellum regions. PVT results revealed significant change between experimental sessions as patients responded faster after IOL replacement. Moreover, a few regions were correlated with the difference in blue light transmittance and the time reaction in PVT. CONCLUSION Current study revealed substantial functional network architecture reorganization associated with cataract extraction and alteration in blue light transmittance.
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Affiliation(s)
- Anna Maria Sobczak
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, 30-348 Kraków, Poland; (M.F.); (E.B.); (H.O.); (N.G.); (T.M.)
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
- Correspondence: (A.M.S.); (B.B.)
| | - Bartosz Bohaterewicz
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, 30-348 Kraków, Poland; (M.F.); (E.B.); (H.O.); (N.G.); (T.M.)
- Department of Psychology of Individual Differences, Psychological Diagnosis, and Psychometrics, Institute of Psychology, University of Social Sciences and Humanities, 03-815 Warsaw, Poland
- Correspondence: (A.M.S.); (B.B.)
| | - Magdalena Fafrowicz
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, 30-348 Kraków, Poland; (M.F.); (E.B.); (H.O.); (N.G.); (T.M.)
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
| | - Aleksandra Domagalik
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
| | - Ewa Beldzik
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, 30-348 Kraków, Poland; (M.F.); (E.B.); (H.O.); (N.G.); (T.M.)
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
| | - Halszka Oginska
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, 30-348 Kraków, Poland; (M.F.); (E.B.); (H.O.); (N.G.); (T.M.)
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
| | - Natalia Golonka
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, 30-348 Kraków, Poland; (M.F.); (E.B.); (H.O.); (N.G.); (T.M.)
| | - Marek Rekas
- Ophthalmology Department, Military Institute of Medicine, 04-349 Warsaw, Poland; (M.R.); (D.B.)
| | - Dominik Bronicki
- Ophthalmology Department, Military Institute of Medicine, 04-349 Warsaw, Poland; (M.R.); (D.B.)
| | - Bożena Romanowska-Dixon
- Department of Ophthalmology and Ocular Oncology, Medical College, Jagiellonian University, 31-008 Kraków, Poland; (B.R.-D.); (J.B.-P.)
| | - Joanna Bolsega-Pacud
- Department of Ophthalmology and Ocular Oncology, Medical College, Jagiellonian University, 31-008 Kraków, Poland; (B.R.-D.); (J.B.-P.)
| | - Waldemar Karwowski
- Computational Neuroergonomics Laboratory, Department of Industrial Engineering & Management Systems, University of Central Florida, Orlando, FL 32816, USA; (W.K.); (F.V.F.)
| | - Farzad V. Farahani
- Computational Neuroergonomics Laboratory, Department of Industrial Engineering & Management Systems, University of Central Florida, Orlando, FL 32816, USA; (W.K.); (F.V.F.)
- Biostatistics Department, John Hopkins University, Baltimore, MD 21218, USA
| | - Tadeusz Marek
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, 30-348 Kraków, Poland; (M.F.); (E.B.); (H.O.); (N.G.); (T.M.)
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
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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.
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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
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11
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Duda M, Domagalik A, Orlowska-Feuer P, Krzysztynska-Kuleta O, Beldzik E, Smyk MK, Stachurska A, Oginska H, Jeczmien-Lazur JS, Fafrowicz M, Marek T, Lewandowski MH, Sarna T. Melanopsin: From a small molecule to brain functions. Neurosci Biobehav Rev 2020; 113:190-203. [DOI: 10.1016/j.neubiorev.2020.03.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/05/2020] [Accepted: 03/09/2020] [Indexed: 12/29/2022]
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Chien SE, Chen YC, Matsumoto A, Yamashita W, Shih KT, Tsujimura SI, Yeh SL. The modulation of background color on perceiving audiovisual simultaneity. Vision Res 2020; 172:1-10. [PMID: 32388209 DOI: 10.1016/j.visres.2020.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 11/28/2022]
Abstract
Perceiving simultaneity is critical in integrating visual and auditory signals that give rise to a unified perception. We examined whether background color modulates people's perception of audiovisual simultaneity. Two hypotheses were proposed and examined: (1) the red-impairment hypothesis: visual processing speed deteriorates when viewing a red background because the magnocellular system is inhibited by red light; and (2) the blue-enhancement hypothesis: the detection of both visual and auditory signals is enhanced when viewing a blue background because it stimulates the blue-light sensitive intrinsically photosensitive retinal ganglion cells (ipRGCs), which trigger a higher alert state. Participants were exposed to different backgrounds while performing an audiovisual simultaneity judgment (SJ) task: a flash and a beep were presented at pre-designated stimulus onset asynchronies (SOAs) and participants judged whether or not the two stimuli were presented simultaneously. Experiment 1 demonstrated a shift of the point of subjective simultaneity (PSS) toward the visual-leading condition in the red compared to the blue background when the flash was presented in the periphery. In Experiment 2, the stimulation of ipRGCs was specifically manipulated to test the blue-enhancement hypothesis. The results showed no support for this hypothesis, perhaps due to top-down cortical modulations. Taken together, the shift of PSS toward the visual-leading condition in the red background was attributed to impaired visual processing speed with respect to auditory processing speed, caused by the inhibition of the magnocellular system under red light.
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Affiliation(s)
- Sung-En Chien
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Yi-Chuan Chen
- Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
| | - Akiko Matsumoto
- Faculty of Science and Engineering, Kagoshima University, Kagoshima, Japan
| | - Wakayo Yamashita
- Faculty of Science and Engineering, Kagoshima University, Kagoshima, Japan
| | - Kuaug-Tsu Shih
- Graduate Institute of Communication Engineering, 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; Center for the Advanced Study in the Behavioral Sciences, Stanford University, USA.
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Šmotek M, Vlček P, Saifutdinova E, Kopřivová J. Objective and Subjective Characteristics of Vigilance under Different Narrow-Bandwidth Light Conditions: Do Shorter Wavelengths Have an Alertness-Enhancing Effect? Neuropsychobiology 2020; 78:238-248. [PMID: 31587007 DOI: 10.1159/000502962] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 08/24/2019] [Indexed: 11/19/2022]
Abstract
The aim of this study was to explore the effects of 20 min of narrow-bandwidth light exposure of different wavelengths (455, 508, and 629 nm, with irradiance of 14 µW/cm2) on various neuropsychological and neurophysiological parameters of vigilance in healthy volunteers and to provide further evidence of the behavioral (subjective sleepiness, reaction time) and electrophysiological (P300 and spectral characteristics) responses to light. The results show that the short-wavelength light condition (455 nm) was found to be most effective in terms of its alerting effect for the following variables: subjective sleepiness, latency of P300 response, and absolute EEG power in higher beta (24-34 Hz) and gamma (35-50 Hz) range at each of the 19 recording electrodes. However, no differences in current power density were observed at the level of cortical EEG sources estimated by exact low-resolution electromagnetic tomography. Our results are in line with other research that shows significant alerting effects of blue (short-wavelength) light in comparison to lights of longer wavelengths. Our results confirm earlier findings that exposure to short-wavelength light during the day may enhance cognitive performance in task-specific scenarios.
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Affiliation(s)
- Michal Šmotek
- National Institute of Mental Health, Klecany, Czechia, .,Third Faculty of Medicine, Charles University in Prague, Prague, Czechia,
| | - Přemysl Vlček
- National Institute of Mental Health, Klecany, Czechia.,Third Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | - Elizaveta Saifutdinova
- National Institute of Mental Health, Klecany, Czechia.,Faculty of Electrical Engineering, Czech Technical University, Prague, Czechia
| | - Jana Kopřivová
- National Institute of Mental Health, Klecany, Czechia.,Third Faculty of Medicine, Charles University in Prague, Prague, Czechia
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Non-Image Forming Effects of Light on Brainwaves, Autonomic Nervous Activity, Fatigue, and Performance. J Circadian Rhythms 2018; 16:9. [PMID: 30220907 PMCID: PMC6137608 DOI: 10.5334/jcr.167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fatigue and sleepiness are one of the main causes of human errors and accidents in the workplace. The empirical evidence has approved that, in addition to stimulating the visual system, light elicits brain responses, which affect physiological and neurobehavioral human functions, known as the non-image forming (NIF) effects of light. As recent evidences have shown the positive effects of red or low correlated color temperature white light on alertness and performance, we investigated whether exposure to 2564 K light could improve subjective and objective measures of alertness and performance compared with 7343 K, 3730 K, and dim light (DL) conditions during the daytime. Twenty two healthy participants were exposed to the light while they were performing a sustained attention task and their electroencephalogram (EEG) and electrocardiogram (ECG) were recorded. Both 2564 K and 7343 K conditions significantly reduced EEG alpha-power compared with the DL and 3730 K conditions. Moreover, the 2564 K, 7343 K, and 3730 K conditions significantly reduced subjective fatigue, sleepiness and increased heart rate and performance compared with the DL condition. Furthermore, the effects of light conditions on alertness and performance varied over the day so that more effective responses were observed during the afternoon hours. These findings suggest that light interventions can be applied to improve daytime performance.
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On the multiple effects of packaging colour on consumer behaviour and product experience in the ‘food and beverage’ and ‘home and personal care’ categories. Food Qual Prefer 2018. [DOI: 10.1016/j.foodqual.2018.03.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Meng Q, Lian Y, Jiang J, Wang W, Hou X, Pan Y, Chu H, Shang L, Wei X, Hao W. Blue light filtered white light induces depression-like responses and temporary spatial learning deficits in rats. Photochem Photobiol Sci 2018; 17:386-394. [PMID: 29404551 DOI: 10.1039/c7pp00271h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Ambient light has a vital impact on mood and cognitive functions. Blue light has been previously reported to play a salient role in the antidepressant effect via melanopsin. Whether blue light filtered white light (BFW) affects mood and cognitive functions remains unclear. The present study aimed to investigate whether BFW led to depression-like symptoms and cognitive deficits including spatial learning and memory abilities in rats, and whether they were associated with the light-responsive function in retinal explants. METHODS Male Sprague-Dawley albino rats were randomly divided into 2 groups (n = 10) and treated with a white light-emitting diode (LED) light source and BFW light source, respectively, under a standard 12 : 12 h L/D condition over 30 days. The sucrose consumption test, forced swim test (FST) and the level of plasma corticosterone (CORT) were employed to evaluate depression-like symptoms in rats. Cognitive functions were assessed by the Morris water maze (MWM) test. A multi-electrode array (MEA) system was utilized to measure electro-retinogram (ERG) responses induced by white or BFW flashes. RESULTS The effect of BFW over 30 days on depression-like responses in rats was indicated by decreased sucrose consumption in the sucrose consumption test, an increased immobility time in the FST and an elevated level of plasma CORT. BFW led to temporary spatial learning deficits in rats, which was evidenced by prolonged escape latency and swimming distances in the spatial navigation test. However, no changes were observed in the short memory ability of rats treated with BFW. The micro-ERG results showed a delayed implicit time and reduced amplitudes evoked by BFW flashes compared to the white flash group. CONCLUSIONS BFW induces depression-like symptoms and temporary spatial learning deficits in rats, which might be closely related to the impairment of light-evoked output signals in the retina.
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Affiliation(s)
- Qinghe Meng
- Department of Toxicology, School of Public Health, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China.
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Richardson C, Micic G, Cain N, Bartel K, Maddock B, Gradisar M. Cognitive performance in adolescents with Delayed Sleep-Wake Phase Disorder: Treatment effects and a comparison with good sleepers. J Adolesc 2018; 65:72-84. [DOI: 10.1016/j.adolescence.2018.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 02/12/2018] [Accepted: 03/05/2018] [Indexed: 12/23/2022]
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Pachito DV, Eckeli AL, Desouky AS, Corbett MA, Partonen T, Rajaratnam SMW, Riera R. Workplace lighting for improving alertness and mood in daytime workers. Cochrane Database Syst Rev 2018; 3:CD012243. [PMID: 29498416 PMCID: PMC6494162 DOI: 10.1002/14651858.cd012243.pub2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Exposure to light plays a crucial role in biological processes, influencing mood and alertness. Daytime workers may be exposed to insufficient or inappropriate light during daytime, leading to mood disturbances and decreases in levels of alertness. OBJECTIVES To assess the effectiveness and safety of lighting interventions to improve alertness and mood in daytime workers. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, seven other databases; ClinicalTrials.gov and the World Health Organization trials portal up to January 2018. SELECTION CRITERIA We included randomised controlled trials (RCTs), and non-randomised controlled before-after trials (CBAs) that employed a cross-over or parallel-group design, focusing on any type of lighting interventions applied for daytime workers. DATA COLLECTION AND ANALYSIS Two review authors independently screened references in two stages, extracted outcome data and assessed risk of bias. We used standardised mean differences (SMDs) and 95% confidence intervals (CI) to pool data from different questionnaires and scales assessing the same outcome across different studies. We combined clinically homogeneous studies in a meta-analysis. We used the GRADE system to rate quality of evidence. MAIN RESULTS The search yielded 2844 references. After screening titles and abstracts, we considered 34 full text articles for inclusion. We scrutinised reports against the eligibility criteria, resulting in the inclusion of five studies (three RCTs and two CBAs) with 282 participants altogether. These studies evaluated four types of comparisons: cool-white light, technically known as high correlated colour temperature (CCT) light versus standard illumination; different proportions of indirect and direct light; individually applied blue-enriched light versus no treatment; and individually applied morning bright light versus afternoon bright light for subsyndromal seasonal affective disorder.We found no studies comparing one level of illuminance versus another.We found two CBA studies (163 participants) comparing high CCT light with standard illumination. By pooling their results via meta-analysis we found that high CCT light may improve alertness (SMD -0.69, 95% CI -1.28 to -0.10; Columbia Jet Lag Scale and the Karolinska Sleepiness Scale) when compared to standard illumination. In one of the two CBA studies with 94 participants there was no difference in positive mood (mean difference (MD) 2.08, 95% CI -0.1 to 4.26) or negative mood (MD -0.45, 95% CI -1.84 to 0.94) assessed using the Positive and Negative Affect Schedule (PANAS) scale. High CCT light may have fewer adverse events than standard lighting (one CBA; 94 participants). Both studies were sponsored by the industry. We graded the quality of evidence as very low.We found no studies comparing light of a particular illuminance and light spectrum or CCT versus another combination of illuminance and light spectrum or CCT.We found no studies comparing daylight versus artificial light.We found one RCT (64 participants) comparing the effects of different proportions of direct and indirect light: 100% direct lighting, 70% direct lighting plus 30% indirect lighting, 30% direct lighting plus 70% indirect lighting and 100% indirect lighting. There was no substantial difference in mood, as assessed by the Beck Depression Inventory, or in adverse events, such as ocular, reading or concentration problems, in the short or medium term. We graded the quality of evidence as low.We found two RCTs comparing individually administered light versus no treatment. According to one RCT with 25 participants, blue-enriched light individually applied for 30 minutes a day may enhance alertness (MD -3.30, 95% CI -6.28 to -0.32; Epworth Sleepiness Scale) and may improve mood (MD -4.8, 95% CI -9.46 to -0.14; Beck Depression Inventory). We graded the quality of evidence as very low. One RCT with 30 participants compared individually applied morning bright light versus afternoon bright light for subsyndromal seasonal affective disorder. There was no substantial difference in alertness levels (MD 7.00, 95% CI -10.18 to 24.18), seasonal affective disorder symptoms (RR 1.60, 95% CI 0.81, 3.20; number of participants presenting with a decrease of at least 50% in SIGH-SAD scores) or frequency of adverse events (RR 0.53, 95% CI 0.26 to 1.07). Among all participants, 57% had a reduction of at least 50% in their SIGH-SAD score. We graded the quality of evidence as low.Publication bias could not be assessed for any of these comparisons. AUTHORS' CONCLUSIONS There is very low-quality evidence based on two CBA studies that high CCT light may improve alertness, but not mood, in daytime workers. There is very low-quality evidence based on one CBA study that high CCT light may also cause less irritability, eye discomfort and headache than standard illumination. There is low-quality evidence based on one RCT that different proportions of direct and indirect light in the workplace do not affect alertness or mood. There is very low-quality evidence based on one RCT that individually applied blue-enriched light improves both alertness and mood. There is low-quality evidence based on one RCT that individually administered bright light during the afternoon is as effective as morning exposure for improving alertness and mood in subsyndromal seasonal affective disorder.
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Affiliation(s)
- Daniela V Pachito
- Centro de Estudos de Saúde Baseada em Evidências e Avaliação Tecnológica em SaúdeCochrane BrazilRua Borges Lagoa, 564 cj 63São PauloSPBrazil04038‐000
| | - Alan L Eckeli
- São Paulo UniversityNeuroscience and Behavioural SciencesCampus UniversitarioRibeirão PretoSão PauloBrazil14.048‐900
| | | | - Mark A Corbett
- Corbett & Associates PtyLtdPO Box 477WalkervilleSouth AustraliaAustralia5081
| | - Timo Partonen
- National Institute for Health and WelfareDepartment of HealthMannerheimintie 166HelsinkiFinlandFI‐00300
| | - Shantha MW Rajaratnam
- Monash UniversitySchool of Psychological Sciences18 Innovation Walk (Building 17)Monash University Clayton CampusClaytonVictoriaAustralia3800
| | - Rachel Riera
- Centro de Estudos de Saúde Baseada em Evidências e Avaliação Tecnológica em SaúdeCochrane BrazilRua Borges Lagoa, 564 cj 63São PauloSPBrazil04038‐000
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Reward priming eliminates color-driven affect in perception. PSYCHOLOGICAL RESEARCH 2018; 83:321-331. [PMID: 29299671 DOI: 10.1007/s00426-017-0966-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 12/18/2017] [Indexed: 10/18/2022]
Abstract
Brain and behavior evidence suggests that colors have distinct affective properties. Here, we investigated how reward influences color-driven affect in perception. In Experiment 1, we assessed competition between blue and red patches during a temporal-order judgment (TOJ) across a range of stimulus onset asynchronies (SOAs). During the value reinforcement, reward was linked to either blue (version 1) or red (version 2) in the experiment. The same stimuli then served as test ones in the following unrewarded, unspeeded TOJ task. Our analysis showed that blue patches were consistently seen as occurring first, even when objectively appearing 2nd at short SOAs. This accelerated perception of blue over red was disrupted by prior primes related to reward (vs. neutral) but not perceptional (blue vs. red) priming. Experiment 2 replicated the findings of Experiment 1 while uncoupling action and stimulus values. These results are consistent with the blue-approach and red-avoidance motivation hypothesis and highlight an active nature of the association of reward priming and color processing. Together, the present study implies a link between reward and color affect and contributes to the understanding of how reward influences color affect in visual processing.
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Knaier R, Schäfer J, Rossmeissl A, Klenk C, Hanssen H, Höchsmann C, Cajochen C, Schmidt-Trucksäss A. Effects of bright and blue light on acoustic reaction time and maximum handgrip strength in male athletes: a randomized controlled trial. Eur J Appl Physiol 2017; 117:1689-1696. [PMID: 28597081 DOI: 10.1007/s00421-017-3659-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 05/29/2017] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess which type of evening light exposure has the greatest effect on reaction time and maximum handgrip strength. These were pre-specified secondary outcomes in a trial which primarily investigated the influence of light on cycling performance. METHODS Seventy-four male athletes were allocated at random to either bright light (BRIGHT), monochromatic blue light (BLUE), or a control condition (CONTROL). Light exposure lasted for 60 min and started 17 h after the individual midpoint of sleep. Reaction time, handgrip strength, and melatonin levels were measured before and after the light exposure. We used analysis of covariance to compare the groups with respect to the investigated outcomes. RESULTS Two participants had to be excluded retrospectively. The remaining 72 participants had a median age of 23 years. The adjusted difference in reaction time was -1 ms [95% confidence interval (CI) -8, 6] for participants in BRIGHT and 2 ms (95% CI -5, 9) for participants in BLUE, both relative to participants in CONTROL. The adjusted difference in handgrip strength was 0.9 kg (95% CI -1.5, 3.3) for participants in BRIGHT and -0.3 kg (95% CI -2.7, 2.0) for participants in BLUE, both relative to participants in CONTROL. After the light exposure, 17% of participants in BRIGHT, 22% in BLUE, and 29% in CONTROL showed melatonin concentrations of 2 pg/ml or higher. CONCLUSIONS The results suggest that bright light might reduce melatonin levels but neither bright nor blue light exposure in the evening seem to improve reaction time or handgrip strength in athletes.
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Affiliation(s)
- Raphael Knaier
- Division Sports and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320 B, 4052, Basel, Switzerland.
| | - Juliane Schäfer
- Division Sports and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320 B, 4052, Basel, Switzerland
- Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital Basel, 4031, Basel, Switzerland
| | - Anja Rossmeissl
- Division Sports and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320 B, 4052, Basel, Switzerland
| | - Christopher Klenk
- Division Sports and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320 B, 4052, Basel, Switzerland
| | - Henner Hanssen
- Division Sports and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320 B, 4052, Basel, Switzerland
| | - Christoph Höchsmann
- Division Sports and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320 B, 4052, Basel, Switzerland
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4056, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
| | - Arno Schmidt-Trucksäss
- Division Sports and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320 B, 4052, Basel, Switzerland
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Vartanian G, Wong KY, Ku PC. LED Lights With Hidden Intensity-Modulated Blue Channels Aiming for Enhanced Subconscious Visual Responses. IEEE PHOTONICS JOURNAL 2017; 9:8201009. [PMID: 28751938 PMCID: PMC5526349 DOI: 10.1109/jphot.2017.2697974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A new form of light-emitting diode (LED) light suitable for general illumination is proposed to enhance subconscious, nonimage-forming visual responses, which are essential to our well-being. Pulsing light has been shown to reduce photoreceptor adaptation and elicit stronger subconscious visual responses at an indoor illumination level. Using the silent substitution technique, a melanopsin-selective flicker can be added into white light. A linear optimization algorithm was developed to suppress any perceivable fluctuation of light intensity and colors of illuminated objects. Two examples of lights are given to illustrate the potential applications of the proposed multi-LED light for general illumination and therapeutic purposes.
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Affiliation(s)
- Garen Vartanian
- Macromolecular Science and Engineering Graduate Program, University
of Michigan, Ann Arbor, MI 48109 USA
| | - Kwoon Y. Wong
- Department of Ophthalmology and Visual Sciences, University of
Michigan, Ann Arbor, MI 48109 USA
| | - Pei-Cheng Ku
- Macromolecular Science and Engineering Graduate Program, University
of Michigan, Ann Arbor, MI 48109 USA
- Department of Electrical Engineering and Computer Science,
University of Michigan, Ann Arbor, MI 48109 USA
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Segal AY, Sletten TL, Flynn-Evans EE, Lockley SW, Rajaratnam SMW. Daytime Exposure to Short- and Medium-Wavelength Light Did Not Improve Alertness and Neurobehavioral Performance. J Biol Rhythms 2016; 31:470-82. [PMID: 27474192 DOI: 10.1177/0748730416659953] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
While previous studies have demonstrated short-wavelength sensitivity to the acute alerting effects of light during the biological night, fewer studies have assessed the alerting effect of light during the daytime. This study assessed the wavelength-dependent sensitivity of the acute alerting effects of daytime light exposure following chronic sleep restriction in 60 young adults (29 men, 31 women; 22.5 ± 3.1 mean ± SD years). Participants were restricted to 5 h time in bed the night before laboratory admission and 3 h time in bed in the laboratory, aligned by wake time. Participants were randomized for exposure to 3 h total of either narrowband blue (λmax 458-480 nm, n = 23) or green light (λmax 551-555 nm, n = 25) of equal photon densities (2.8-8.4 × 10(13) photons/cm(2)/sec), beginning 3.25 h after waking, and compared with a darkness control (0 lux, n = 12). Subjective sleepiness (Karolinska Sleepiness Scale), sustained attention (auditory Psychomotor Vigilance Task), mood (Profile of Mood States Bi-Polar form), working memory (2-back task), selective attention (Stroop task), and polysomnographic and ocular sleepiness measures (Optalert) were assessed prior to, during, and after light exposure. We found no significant effect of light wavelength on these measures, with the exception of a single mood subscale. Further research is needed to optimize the characteristics of lighting systems to induce alerting effects during the daytime, taking into account potential interactions between homeostatic sleep pressure, circadian phase, and light responsiveness.
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Affiliation(s)
- Ahuva Y Segal
- Monash Institute of Cognitive and Clinical Neurosciences, Sleep and Circadian Medicine Laboratory, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Tracey L Sletten
- Monash Institute of Cognitive and Clinical Neurosciences, Sleep and Circadian Medicine Laboratory, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Erin E Flynn-Evans
- 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
- Monash Institute of Cognitive and Clinical Neurosciences, Sleep and Circadian Medicine Laboratory, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Shantha M W Rajaratnam
- Monash Institute of Cognitive and Clinical Neurosciences, Sleep and Circadian Medicine Laboratory, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, Massachusetts, USA
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Slama H, Deliens G, Schmitz R, Peigneux P, Leproult R. Afternoon nap and bright light exposure improve cognitive flexibility post lunch. PLoS One 2015; 10:e0125359. [PMID: 26016658 PMCID: PMC4446306 DOI: 10.1371/journal.pone.0125359] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 03/12/2015] [Indexed: 11/18/2022] Open
Abstract
Beneficial effects of napping or bright light exposure on cognitive performance have been reported in participants exposed to sleep loss. Nonetheless, few studies investigated the effect of these potential countermeasures against the temporary drop in performance observed in mid-afternoon, and even less so on cognitive flexibility, a crucial component of executive functions. This study investigated the impact of either an afternoon nap or bright light exposure on post-prandial alterations in task switching performance in well-rested participants. Twenty-five healthy adults participated in two randomized experimental conditions, either wake versus nap (n=15), or bright light versus placebo (n=10). Participants were tested on a switching task three times (morning, post-lunch and late afternoon sessions). The interventions occurred prior to the post-lunch session. In the nap/wake condition, participants either stayed awake watching a 30-minute documentary or had the opportunity to take a nap for 30 minutes. In the bright light/placebo condition, participants watched a documentary under either bright blue light or dim orange light (placebo) for 30 minutes. The switch cost estimates cognitive flexibility and measures task-switching efficiency. Increased switch cost scores indicate higher difficulties to switch between tasks. In both control conditions (wake or placebo), accuracy switch-cost score increased post lunch. Both interventions (nap or bright light) elicited a decrease in accuracy switch-cost score post lunch, which was associated with diminished fatigue and decreased variability in vigilance. Additionally, there was a trend for a post-lunch benefit of bright light with a decreased latency switch-cost score. In the nap group, improvements in accuracy switch-cost score were associated with more NREM sleep stage N1. Thus, exposure to bright light during the post-lunch dip, a countermeasure easily applicable in daily life, results in similar beneficial effects as a short nap on performance in the cognitive flexibility domain with possible additional benefits on latency switch-cost scores.
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Affiliation(s)
- Hichem Slama
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN -Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- UNESCOG - Research Unit in Cognitive Neurosciences at CRCN - Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Gaétane Deliens
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN -Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- CO3 - Consciousness, Cognition & Computation Group at CRCN - Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Rémy Schmitz
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN -Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- LABNIC - Laboratory for Neurology and Imaging of Cognition, Department of Neuroscience and Clinic of Neurology, Campus Biotech, University of Geneva, Geneva, Switzerland
| | - Philippe Peigneux
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN -Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Rachel Leproult
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN -Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- * E-mail:
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Elliot AJ. Color and psychological functioning: a review of theoretical and empirical work. Front Psychol 2015; 6:368. [PMID: 25883578 PMCID: PMC4383146 DOI: 10.3389/fpsyg.2015.00368] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/16/2015] [Indexed: 11/17/2022] Open
Abstract
In the past decade there has been increased interest in research on color and psychological functioning. Important advances have been made in theoretical work and empirical work, but there are also important weaknesses in both areas that must be addressed for the literature to continue to develop apace. In this article, I provide brief theoretical and empirical reviews of research in this area, in each instance beginning with a historical background and recent advancements, and proceeding to an evaluation focused on weaknesses that provide guidelines for future research. I conclude by reiterating that the literature on color and psychological functioning is at a nascent stage of development, and by recommending patience and prudence regarding conclusions about theory, findings, and real-world application.
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Affiliation(s)
- Andrew J Elliot
- Department of Clinical and Social Sciences in Psychology, University of Rochester, Rochester, NY USA
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Sroykham W, Wongsathikun J, Wongsawat Y. The effects of perceiving color in living environment on QEEG, oxygen saturation, pulse rate, and emotion regulation in humans. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:6226-9. [PMID: 25571419 DOI: 10.1109/embc.2014.6945051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Light and color have been shown to have substantial physical, psychological and sociological effects on humans. Hence, an investigation on the effect of changes in light and color to the biological signals is a challenging problem. Five participants were measured the oxygen saturation (SpO2), pulse rate, and quantitative electroencephalogram (QEEG) in six colors (white, blue, green, yellow, red and black) of living environment for 5 minutes per color. Then all participants were asked to answer the emotional questionnaire of BRUMS and color performance for each color environment. The results showed brain activity of high beta wave (25-30 Hz) that associated with alertness, agitation, mental activity, and general activation of mind and body functions (at frontal lobes and temporal lobes) in red and yellow colored rooms were higher than blue, green, white and black colored rooms, respectively. It also had the relationship with the psychological effect (BRUMS). The amplitude asymmetry of beta wave (12-25 Hz) was highly attenuated in warm color (red and yellow colored rooms), moderately attenuated in cool color (green and blue colored room) and little attenuated in white and black colored rooms. The BRUMS showed that red and yellow yielded significant effect on anger (F = 4.966, p = 0.002) and confusion (F=3.853, p=0.008). Red and green color yielded high effect on vigor. Green color did not affect the depression. Blue color yielded moderate effect on confusion, tension and fatigue. White and black colors yielded low effect on any mood, but black color had no effect on vigor. In addition, we cannot observe any significant changes of pulse rate and blood oxygen saturation in each color. The results can possibly be used as the recommendation to design the room for either normal people or patients.
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Rahman SA, Flynn-Evans EE, Aeschbach D, Brainard GC, Czeisler CA, Lockley SW. Diurnal spectral sensitivity of the acute alerting effects of light. Sleep 2014; 37:271-81. [PMID: 24501435 DOI: 10.5665/sleep.3396] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Previous studies have demonstrated short-wavelength sensitivity for the acute alerting response to nocturnal light exposure. We assessed daytime spectral sensitivity in alertness, performance, and waking electroencephalogram (EEG). DESIGN Between-subjects (n = 8 per group). SETTING Inpatient intensive physiologic monitoring unit. PARTICIPANTS Sixteen healthy young adults (mean age ± standard deviation = 23.8 ± 2.7 y). INTERVENTIONS Equal photon density exposure (2.8 × 10(13) photons/cm(2)/s) to monochromatic 460 nm (blue) or 555 nm (green) light for 6.5 h centered in the middle of the 16-h episode of wakefulness during the biological day. Results were compared retrospectively to 16 individuals who were administered the same light exposure during the night. MEASUREMENTS AND RESULTS Daytime and nighttime 460-nm light exposure significantly improved auditory reaction time (P < 0.01 and P < 0.05, respectively) and reduced attentional lapses (P < 0.05), and improved EEG correlates of alertness compared to 555-nm exposure. Whereas subjective sleepiness ratings did not differ between the two spectral conditions during the daytime (P > 0.05), 460-nm light exposure at night significantly reduced subjective sleepiness compared to 555-nm light exposure at night (P < 0.05). Moreover, nighttime 460-nm exposure improved alertness to near-daytime levels. CONCLUSIONS The alerting effects of short-wavelength 460-nm light are mediated by counteracting both the circadian drive for sleepiness and homeostatic sleep pressure at night, but only via reducing the effects of homeostatic sleep pressure during the day.
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Affiliation(s)
- Shadab A Rahman
- Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA ; Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA
| | - Erin E Flynn-Evans
- Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA ; Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA
| | - Daniel Aeschbach
- Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA ; Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA ; Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - George C Brainard
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA
| | - Charles A Czeisler
- Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA ; Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA
| | - Steven W Lockley
- Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA ; Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA
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Sivaji A, Shopian S, Nor ZM, Chuan NK, Bahri S. Lighting does Matter: Preliminary Assessment on Office Workers. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.sbspro.2013.10.283] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Beaven CM, Ekström J. A comparison of blue light and caffeine effects on cognitive function and alertness in humans. PLoS One 2013; 8:e76707. [PMID: 24282477 PMCID: PMC3838207 DOI: 10.1371/journal.pone.0076707] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/24/2013] [Indexed: 11/18/2022] Open
Abstract
The alerting effects of both caffeine and short wavelength (blue) light have been consistently reported. The ability of blue light to enhance alertness and cognitive function via non-image forming neuropathways have been suggested as a non-pharmacological countermeasure for drowsiness across a range of occupational settings. Here we compare and contrast the alerting and psychomotor effects of 240 mg of caffeine and a 1-h dose of ~40 lx blue light in a non-athletic population. Twenty-one healthy subjects performed a computer-based psychomotor vigilance test before and after each of four randomly assigned trial conditions performed on different days: white light/placebo; white light/240 mg caffeine; blue light/placebo; blue light/240 mg caffeine. The Karolinska Sleepiness Scale was used to assess subjective measures of alertness. Both the caffeine only and blue light only conditions enhanced accuracy in a visual reaction test requiring a decision and an additive effect was observed with respect to the fastest reaction times. However, in a test of executive function, where a distraction was included, caffeine exerted a negative effect on accuracy. Furthermore, the blue light only condition consistently outperformed caffeine when both congruent and incongruent distractions were presented. The visual reactions in the absence of a decision or distraction were also enhanced in the blue light only condition and this effect was most prominent in the blue-eyed participants. Overall, blue light and caffeine demonstrated distinct effects on aspects of psychomotor function and have the potential to positively influence a range of settings where cognitive function and alertness are important. Specifically, despite the widespread use of caffeine in competitive sporting environments, the possible impact of blue light has received no research attention.
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Affiliation(s)
- C. Martyn Beaven
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
- *E-mail:
| | - Johan Ekström
- Department of Psychology, Mid Sweden University, Östersund, Sweden
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Perret M, Gomez D, Barbosa A, Aujard F, Théry M. Increased late night response to light controls the circadian pacemaker in a nocturnal primate. J Biol Rhythms 2010; 25:186-96. [PMID: 20484690 DOI: 10.1177/0748730410368244] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mammalian endogenous circadian clock, the suprachiasmatic nuclei, receives environmental inputs, namely the light-dark cycle, through photopigments located in the eye and from melanopsin-expressing retinal ganglion cells. The authors investigated the influence of light wavelength and intensity on the synchronization of the rest-activity rhythm of the gray mouse lemur, a nocturnal Malagasy primate. Animals were tested at different irradiance levels (320, 45, 13, and 6 nmol x m(-2) x s(- 1)) under several light wavelengths (from 400 to 610 nm). Several parameters including circadian period, activity, and body temperature waveforms were used to assess synchronization to a 12:12 light-dark cycle in comparison to control treatments (12:12 white light or continuous darkness). Entrainment of the circadian rest-activity cycle increased with light intensity. It was more efficient for mid wavelengths relative to shorter or longer wavelengths but not coincident with melanopsin maximal sensitivity, suggesting other photoreceptors are likely involved in lemurs' photoentrainment. The authors obtained a novel synchronization pattern characterized by a clear synchronization to lights-on only without phasing to lights-off. Changes in photo-responsiveness at dusk and dawn highlight differential responses of evening and morning oscillators in the circadian clock.
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Affiliation(s)
- Martine Perret
- UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Département d'Ecologie et Gestion de la Biodiversité, Brunoy, France.
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Alexopoulos P, Lehrl S, Richter-Schmidinger T, Kreusslein A, Hauenstein T, Bayerl F, Jung P, Kneib T, Kurz A, Kornhuber J, Bleich S. Short-term influence of elevation of plasma homocysteine levels on cognitive function in young healthy adults. J Nutr Health Aging 2010; 14:283-7. [PMID: 20305995 DOI: 10.1007/s12603-010-0062-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Acute homocysteine elevation has been shown to have a significant impact on cognitive function in animal models. OBJECTIVES Investigation of the short-term impact of elevation of plasma homocysteine levels through a dietary intervention on cognitive abilities of young healthy adults. PARTICIPANTS 100 healthy medical students of both genders were enrolled in the study. DESIGN AND MEASUREMENTS Homocysteine levels and cognitive abilities were measured at 08:30 (before breakfast) and at 15:00 (two hours after lunch and six hours after breakfast). Food intake was restricted to specified comestibles. The cognitive assessment comprised a version of the Short Test for General Intelligence, three subtests of the Syndrome Short Test and the Stroop test. RESULTS At 15:00 plasma homocysteine was significantly elevated in 56 participants (P < 0.00001), whilst in 44 it was decreased (P < 0.00001) in comparison to baseline (08:30). The decrease was however of limited clinical significance. The differences in the changes in cognitive performance between the two groups did not attain statistical significance (P > 0.05) and the direction of the changes did not differ between them. Accordingly, the multiple linear regression analysis did not reveal an important influence of homocysteine elevation on cognitive performance variations. CONCLUSIONS Significant increase of plasma homocysteine is not associated with a straightforward inhibitory or facilitatory short-term effect on physiological cognitive parameters in young healthy adults.
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Affiliation(s)
- P Alexopoulos
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
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Mainster MA, Turner PL. Blue-blocking IOLs decrease photoreception without providing significant photoprotection. Surv Ophthalmol 2009; 55:272-89. [PMID: 19883931 DOI: 10.1016/j.survophthal.2009.07.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 07/16/2009] [Accepted: 07/31/2009] [Indexed: 12/22/2022]
Abstract
Violet and blue light are responsible for 45% of scotopic, 67% of melanopsin, 83% of human circadian (melatonin suppression) and 94% of S-cone photoreception in pseudophakic eyes (isoilluminance source). Yellow chromophores in blue-blocking intraocular lenses (IOLs) eliminate between 43 and 57% of violet and blue light between 400 and 500 nm, depending on their dioptric power. This restriction adversely affects pseudophakic photopic luminance contrast, photopic S-cone foveal threshold, mesopic contrast acuity, scotopic short-wavelength sensitivity and circadian photoreception. Yellow IOL chromophores provide no tangible clinical benefits in exchange for the photoreception losses they cause. They fail to decrease disability glare or improve contrast sensitivity. Most epidemiological evidence shows that environmental light exposure and cataract surgery are not significant risk factors for the progression of age-related macular degeneration (AMD). Thus, the use of blue-blocking IOLs is not evidence-based medicine. Most AMD occurs in phakic adults over 60 years of age, despite crystalline lens photoprotection far greater than that of blue-blocking IOLs. Therefore, if light does play some role in the pathogenesis of AMD, then 1) senescent crystalline lenses do not prevent it, so neither can blue-blocking IOLs that offer far less photoprotection, and 2) all pseudophakes should wear sunglasses in bright environments. Pseudophakes have the freedom to remove their sunglasses for optimal photoreception whenever they choose to do so, provided that they are not encumbered permanently by yellow IOL chromophores. In essence, yellow chromophores are placebos for prevention of AMD that permanently restrict a pseudophake's dim light and circadian photoreception at ages when they are needed most. If yellow IOLs had been the standard of care, then colorless UV-blocking IOLs could be advocated now as "premium" IOLs because they offer dim light and circadian photoreception roughly 15-20 years more youthful than blue-blocking IOLs.
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Affiliation(s)
- Martin A Mainster
- Department of Ophthalmology, University of Kansas School of Medicine, Prairie Village, Kansas, USA.
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Anderson JL, Glod CA, Dai J, Cao Y, Lockley SW. Lux vs. wavelength in light treatment of Seasonal Affective Disorder. Acta Psychiatr Scand 2009; 120:203-12. [PMID: 19207131 DOI: 10.1111/j.1600-0447.2009.01345.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Published dosing guidelines for treatment of Seasonal Affective Disorder (SAD) refer to photopic lux, which is not appropriate for short-wavelength light. Short wavelengths are most potent for many non-visual responses to light. If SAD therapy were similarly mediated, standards utilizing lux risk overestimating necessary dose. We investigated antidepressant responses to light using two light-emitting diode (LED) sources, each emitting substantial short-wavelength light, but <2500 lux. METHOD A randomized, double-blind trial investigated 3-week 45 min/day out-patient treatment with blue-appearing (goLITE) or blue-enriched white-appearing light in 18 moderately-depressed adults (12F, 49.1 +/- 9.5 years). Equivalent numbers of photons within the short-wavelength range were emitted, but the white source emitted twice as many photons overall and seven-fold more lux. RESULTS Depression ratings (SIGH-ADS; http://www.cet.org) decrease averaged 82% (SD = 17%) from baseline (P < 0.0001) in both white- and blue-light groups. Both sources were well tolerated. CONCLUSION Short-wavelength LED light sources may be effective in SAD treatment at fewer lux than traditional fluorescent sources.
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Affiliation(s)
- J L Anderson
- Department of Psychiatry, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Hoffmann G, Gufler V, Griesmacher A, Bartenbach C, Canazei M, Staggl S, Schobersberger W. Effects of variable lighting intensities and colour temperatures on sulphatoxymelatonin and subjective mood in an experimental office workplace. APPLIED ERGONOMICS 2008; 39:719-728. [PMID: 18164275 DOI: 10.1016/j.apergo.2007.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 11/02/2007] [Accepted: 11/17/2007] [Indexed: 05/25/2023]
Abstract
Workplace illumination is of paramount importance in determining the employee's productivity and well-being. Moreover, light exerts non-visual effects with respect to biological rhythms. In this study, we investigated the impact of different lighting conditions (500-1800 lx, 6500 K; 500 lx, 4000 K) on sulphatoxymelatonin (aMT6-s) and subjective mood in an experimental office accommodation. Urinary aMT6-s concentrations were significantly decreased at all days of the experiment in both lights. On day 3, differences between aMT6-s concentrations in specimen collected at 05:00 p.m. and at 09:00 a.m. were significantly higher under variable lighting conditions. Analyses of a mood rating inventory revealed a benefit of variable light with respect to the dimensions of "Activity", while "Deactivation" and "Fatigue" were increased in regular light on day 1. "Activity", "Concentration", and "Deactivation" changed in opposite directions when comparing variable with regular illumination on two consecutive days. In conclusion, variable light exerts a potential advantage in indoor office accommodations with respect to subjective mood, although no unequivocal differences in the profile of aMT6-s were found as compared to regular light.
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Affiliation(s)
- Georg Hoffmann
- Institute for Leisure, Travel, and Alpine Medicine, University for Health Sciences, Medical Informatics, and Technology, Eduard Wallnoefer-Zentrum 1, A-6060 Hall, Austria.
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Turner PL, Mainster MA. Circadian photoreception: ageing and the eye's important role in systemic health. Br J Ophthalmol 2008; 92:1439-44. [PMID: 18757473 PMCID: PMC2582340 DOI: 10.1136/bjo.2008.141747] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To analyse how age-related losses in crystalline lens transmittance and pupillary area affect circadian photoreception and compare the circadian performance of phakic and pseudophakic individuals of the same age. METHODS The spectral sensitivity of circadian photoreception peaks in the blue part of the spectrum at approximately 460 nm. Photosensitive retinal ganglion cells send unconscious information about environmental illumination to non-visual brain centres including the human body's master biological clock in the suprachiasmatic nuclei. This information permits human physiology to be optimised and aligned with geophysical day-night cycles using neural and hormonal messengers including melatonin. Age-related transmittance spectra of crystalline lenses and photopic pupil diameter are used with the spectral sensitivity of melatonin suppression and the transmittance spectra of intraocular lenses (IOLs) to analyse how ageing and IOL chromophores affect circadian photoreception. RESULTS Ageing increases crystalline lens light absorption and decreases pupil area resulting in progressive loss of circadian photoreception. A 10-year-old child has circadian photoreception 10-fold greater than a 95-year-old phakic adult. A 45-year-old adult retains only half the circadian photoreception of early youth. Pseudophakia improves circadian photoreception at all ages, particularly with UV-only blocking IOLs which transmit blue wavelengths optimal for non-visual photoreception. CONCLUSIONS Non-visual retinal ganglion photoreceptor responses to bright, properly timed light exposures help assure effective circadian photoentrainment and optimal diurnal physiological processes. Circadian photoreception can persist in visually blind individuals if retinal ganglion cell photoreceptors and their suprachiasmatic connections are intact. Retinal illumination decreases with ageing due to pupillary miosis and reduced crystalline lens light transmission especially of short wavelengths. Inadequate environmental light and/or ganglion photoreception can cause circadian disruption, increasing the risk of insomnia, depression, numerous systemic disorders and possibly early mortality. Artificial lighting is dimmer and less blue-weighted than natural daylight, contributing to age-related losses in unconscious circadian photoreception. Optimal intraocular lens design should consider the spectral requirements of both conscious and unconscious retinal photoreception.
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Affiliation(s)
- P L Turner
- Department of Ophthalmology, University of Kansas School of Medicine, Prairie Village, KS 66208-3444, USA.
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Lockley SW. Spectral Sensitivity of Circadian, Neuroendocrine and Neurobehavioral Effects of Light. ACTA ACUST UNITED AC 2008. [DOI: 10.1618/jhes.11.43] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Steven W. Lockley
- Division of Sleep Medicine, Brigham and Women's Hospital, and Division of Sleep Medicine, Harvard Medical School
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Phelps J. Dark therapy for bipolar disorder using amber lenses for blue light blockade. Med Hypotheses 2008; 70:224-9. [PMID: 17637502 DOI: 10.1016/j.mehy.2007.05.026] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2007] [Accepted: 05/22/2007] [Indexed: 12/12/2022]
Abstract
"Dark Therapy", in which complete darkness is used as a mood stabilizer in bipolar disorder, roughly the converse of light therapy for depression, has support in several preliminary studies. Although data are limited, darkness itself appears to organize and stabilize circadian rhythms. Yet insuring complete darkness from 6 p.m. to 8 a.m. the following morning, as used in several studies thus far, is highly impractical and not accepted by patients. However, recent data on the physiology of human circadian rhythm suggests that "virtual darkness" may be achievable by blocking blue wavelengths of light. A recently discovered retinal photoreceptor, whose fibers connect only to the biological clock region of the hypothalamus, has been shown to respond only to a narrow band of wavelengths around 450 nm. Amber-tinted safety glasses, which block transmission of these wavelengths, have already been shown to preserve normal nocturnal melatonin levels in a light environment which otherwise completely suppresses melatonin production. Therefore it may be possible to influence human circadian rhythms by using these lenses at night to blunt the impact of electrical light, particularly the blue light of ubiquitous television screens, by creating a "virtual darkness". One way to investigate this would be to provide the lenses to patients with severe sleep disturbance of probable circadian origin. A preliminary case series herein demonstrates that some patients with bipolar disorder experience reduced sleep-onset latency with this approach, suggesting a circadian effect. If amber lenses can effectively simulate darkness, a broad range of conditions might respond to this inexpensive therapeutic tool: common forms of insomnia; sleep deprivation in nursing mothers; circadian rhythm disruption in shift workers; and perhaps even rapid cycling bipolar disorder, a difficult- to -treat variation of a common illness.
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Affiliation(s)
- James Phelps
- Corvallis Psychiatric Clinic, 3517 Samaritan Drive, Corvallis, OR 97330, United States.
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