scholarly journals Daytime Exposure to Short Wavelength-Enriched Light Improves Cognitive Performance in Sleep-Restricted College-Aged Adults

2021 ◽  
Vol 12 ◽  
Author(s):  
Leilah K. Grant ◽  
Brianne A. Kent ◽  
Matthew D. Mayer ◽  
Robert Stickgold ◽  
Steven W. Lockley ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
White Light ◽  
Short Wavelength ◽  
Light Exposure ◽  
Vertical Plane ◽  
Learning Task ◽  
Built Environments ◽  
Motor Sequence ◽  
Lighting Conditions ◽  
Addition Task

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.

scholarly journals Light, Alertness, and Alerting Effects of White Light: A Literature Overview

2018 ◽  
Vol 33 (6) ◽  
pp. 589-601 ◽  
Author(s):  
Renske Lok ◽  
Karin C. H. J. Smolders ◽  
Domien G. M. Beersma ◽  
Yvonne A. W. de Kort
Keyword(s):  
White Light ◽  
Light Exposure ◽  
Neural Mechanisms ◽  
Dependent Manner ◽  
Experimental Paradigm ◽  
Research Paradigms ◽  
Lighting Conditions ◽  
Literature Overview ◽  
Dose Dependent ◽  
As Effects

Light is known to elicit non–image-forming responses, such as effects on alertness. This has been reported especially during light exposure at night. Nighttime results might not be translatable to the day. This article aims to provide an overview of (1) neural mechanisms regulating alertness, (2) ways of measuring and quantifying alertness, and (3) the current literature specifically regarding effects of different intensities of white light on various measures and correlates of alertness during the daytime. In general, the present literature provides inconclusive results on alerting effects of the intensity of white light during daytime, particularly for objective measures and correlates of alertness. However, the various research paradigms employed in earlier studies differed substantially, and most studies tested only a limited set of lighting conditions. Therefore, the alerting potential of exposure to more intense white light should be investigated in a systematic, dose-dependent manner with multiple correlates of alertness and within one experimental paradigm over the course of day.

scholarly journals Light and chronobiology: implications for health and disease

2012 ◽  
Vol 14 (4) ◽  
pp. 448-453 ◽  
Keyword(s):  
Cognitive Performance ◽  
Light Exposure ◽  
Biological Clock ◽  
Spectral Composition ◽  
Light Therapy ◽  
Lighting Conditions ◽  
Environmental Light ◽  
Health And Disease ◽  
Peripheral Clocks ◽  
Indoor Lighting

Environmental light synchronizes the primary mammalian biological clock in the suprachiasmatic nuclei, as well as many peripheral clocks in tissues and cells, to the solar 24-hour day. Light is the strongest synchronizing agent (zeitgeber) for the circadian system, and therefore keeps most biological and psychological rhythms internally synchronized, which is important for optimum function. Circadian sleep-wake disruptions and chronic circadian misalignment, as often observed in psychiatric and neurodegenerative illness, can be treated with light therapy. The beneficial effect on circadian synchronization, sleep quality, mood, and cognitive performance depends on timing, intensity, and spectral composition of light exposure. Tailoring and optimizing indoor lighting conditions may be an approach to improve wellbeing, alertness, and cognitive performance and, in the long term, producing health benefits.

scholarly journals Light in the Senior Home: Effects of Dynamic and Individual Light Exposure on Sleep, Cognition, and Well-Being

2020 ◽  
Vol 2 (4) ◽  
pp. 557-576
Author(s):  
Myriam Juda ◽  
Teresa Liu-Ambrose ◽  
Fabio Feldman ◽  
Cristian Suvagau ◽  
Ralph E. Mistlberger
Keyword(s):  
Cognitive Performance ◽  
Light Exposure ◽  
Activity Rhythm ◽  
Well Being ◽  
Lighting Condition ◽  
Pooled Data ◽  
Lighting Conditions ◽  
Nursing Home Patients ◽  
Exposure Levels ◽  
Rest Activity

Disrupted sleep is common among nursing home patients and is associated with cognitive decline and reduced well-being. Sleep disruptions may in part be a result of insufficient daytime light exposure. This pilot study examined the effects of dynamic “circadian” lighting and individual light exposure on sleep, cognitive performance, and well-being in a sample of 14 senior home residents. The study was conducted as a within-subject study design over five weeks of circadian lighting and five weeks of conventional lighting, in a counterbalanced order. Participants wore wrist accelerometers to track rest–activity and light profiles and completed cognitive batteries (National Institute of Health (NIH) toolbox) and questionnaires (depression, fatigue, sleep quality, lighting appraisal) in each condition. We found no significant differences in outcome variables between the two lighting conditions. Individual differences in overall (indoors and outdoors) light exposure levels varied greatly between participants but did not differ between lighting conditions, except at night (22:00–6:00), with maximum light exposure being greater in the conventional lighting condition. Pooled data from both conditions showed that participants with higher overall morning light exposure (6:00–12:00) had less fragmented and more stable rest–activity rhythms with higher relative amplitude. Rest–activity rhythm fragmentation and long sleep duration both uniquely predicted lower cognitive performance.

scholarly journals Effects of Daytime Electric Light Exposure on Human Alertness and Higher Cognitive Functions: A Systematic Review

2022 ◽  
Vol 12 ◽  
Author(s):  
Mushfiqul Anwar Siraji ◽  
Vineetha Kalavally ◽  
Alexandre Schaefer ◽  
Shamsul Haque
Keyword(s):  
Systematic Review ◽  
Task Performance ◽  
White Light ◽  
Cognitive Functions ◽  
Short Wavelength ◽  
Light Exposure ◽  
Complex Task ◽  
Simple Task ◽  
Beneficial Effects ◽  
Higher Cognitive Functions

This paper reports the results of a systematic review conducted on articles examining the effects of daytime electric light exposure on alertness and higher cognitive functions. For this, we selected 59 quantitative research articles from 11 online databases. The review protocol was registered with PROSPERO (CRD42020157603). The results showed that both short-wavelength dominant light exposure and higher intensity white light exposure induced alertness. However, those influences depended on factors like the participants’ homeostatic sleep drive and the time of day the participants received the light exposure. The relationship between light exposure and higher cognitive functions was not as straightforward as the alerting effect. The optimal light property for higher cognitive functions was reported dependent on other factors, such as task complexity and properties of control light. Among the studies with short-wavelength dominant light exposure, ten studies (morning: 3; afternoon: 7) reported beneficial effects on simple task performances (reaction time), and four studies (morning: 3; afternoon: 1) on complex task performances. Four studies with higher intensity white light exposure (morning: 3; afternoon: 1) reported beneficial effects on simple task performance and nine studies (morning: 5; afternoon: 4) on complex task performance. Short-wavelength dominant light exposure with higher light intensity induced a beneficial effect on alertness and simple task performances. However, those effects did not hold for complex task performances. The results indicate the need for further studies to understand the influence of short-wavelength dominant light exposure with higher illuminance on alertness and higher cognitive functions.

scholarly journals Investigating the Effects of Seizures on Procedural Memory Performance in Patients with Epilepsy

2021 ◽  
Vol 11 (2) ◽  
pp. 261
Author(s):  
Frank J. van Schalkwijk ◽  
Walter R. Gruber ◽  
Laurie A. Miller ◽  
Eugen Trinka ◽  
Yvonne Höller
Keyword(s):  
Temporal Lobe ◽  
Declarative Memory ◽  
Memory Performance ◽  
Total Sample ◽  
Learning Task ◽  
Procedural Memory ◽  
Memory Retention ◽  
Motor Sequence ◽  
Performance Improvements ◽  
Patients With Epilepsy

Memory complaints are frequently reported by patients with epilepsy and are associated with seizure occurrence. Yet, the direct effects of seizures on memory retention are difficult to assess given their unpredictability. Furthermore, previous investigations have predominantly assessed declarative memory. This study evaluated within-subject effects of seizure occurrence on retention and consolidation of a procedural motor sequence learning task in patients with epilepsy undergoing continuous monitoring for five consecutive days. Of the total sample of patients considered for analyses (N = 53, Mage = 32.92 ± 13.80 y, range = 18–66 y; 43% male), 15 patients experienced seizures and were used for within-patient analyses. Within-patient contrasts showed general improvements over seizure-free (day + night) and seizure-affected retention periods. Yet, exploratory within-subject contrasts for patients diagnosed with temporal lobe epilepsy (n = 10) showed that only seizure-free retention periods resulted in significant improvements, as no performance changes were observed following seizure-affected retention. These results indicate general performance improvements and offline consolidation of procedural memory during the day and night. Furthermore, these results suggest the relevance of healthy temporal lobe functioning for successful consolidation of procedural information, as well as the importance of seizure control for effective retention and consolidation of procedural memory.

Severity of Ongoing Post-Concussive Symptoms as a Predictor of Cognitive Performance Following a Pediatric Mild Traumatic Brain Injury

2020 ◽  
pp. 1-11
Author(s):  
Veronik Sicard ◽  
Danielle C. Hergert ◽  
Sharvani Pabbathi Reddy ◽  
Cidney R. Robertson-Benta ◽  
Andrew B. Dodd ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cognitive Performance ◽  
Mild Traumatic Brain Injury ◽  
Parental Education ◽  
Visual Learning ◽  
Learning Task ◽  
Risk Scores ◽  
Group Differences ◽  
Post Injury

Abstract Objective: This study aimed to examine the predictors of cognitive performance in patients with pediatric mild traumatic brain injury (pmTBI) and to determine whether group differences in cognitive performance on a computerized test battery could be observed between pmTBI patients and healthy controls (HC) in the sub-acute (SA) and the early chronic (EC) phases of injury. Method: 203 pmTBI patients recruited from emergency settings and 159 age- and sex-matched HC aged 8–18 rated their ongoing post-concussive symptoms (PCS) on the Post-Concussion Symptom Inventory and completed the Cogstate brief battery in the SA (1–11 days) phase of injury. A subset (156 pmTBI patients; 144 HC) completed testing in the EC (∼4 months) phase. Results: Within the SA phase, a group difference was only observed for the visual learning task (One-Card Learning), with pmTBI patients being less accurate relative to HC. Follow-up analyses indicated higher ongoing PCS and higher 5P clinical risk scores were significant predictors of lower One-Card Learning accuracy within SA phase, while premorbid variables (estimates of intellectual functioning, parental education, and presence of learning disabilities or attention-deficit/hyperactivity disorder) were not. Conclusions: The absence of group differences at EC phase is supportive of cognitive recovery by 4 months post-injury. While the severity of ongoing PCS and the 5P score were better overall predictors of cognitive performance on the Cogstate at SA relative to premorbid variables, the full regression model explained only 4.1% of the variance, highlighting the need for future work on predictors of cognitive outcomes.

Influence of the perceived size of a light source on non-visual effects in humans

2020 ◽  
Vol 9 (6) ◽  
pp. 385-393
Author(s):  
Arvid Niemeyer ◽  
Lucia Rottmair ◽  
Cornelius Neumann ◽  
Cornelius Möckel
Keyword(s):  
Working Memory ◽  
Light Exposure ◽  
Error Rates ◽  
Positive Contribution ◽  
Measurement Point ◽  
Visual Effects ◽  
Lighting Conditions ◽  
Light Measurement ◽  
And Performance ◽  
Main Effects

AbstractLight not only enables humans to perceive their surroundings, but also influences their sleep–wake cycle, mood, concentration and performance. Targeted use of these so called nonvisual effects could also have a positive contribution in automobiles by keeping passengers alert, minimizing error rates or bootsting attention in general. Since construction space in vehicle interios is scarce, this study compared the influence of differently-sized light panels and thus solid angles on nonvisual effects. In a counterbalanced order, 32 volunteers were exposed to three lighting conditions in the morning: baseline (12 lx, 2200 K), small (200 lx, 6500 K, 0.05 sr) and large (200 lx, 6500 K, 0.44 sr). During each session of 60 min, alertness, concentration and working memory were assessed before and during light exposure. After data analysis no significant main effects of light, measurement point or interaction between light and measurement point could be seen.

Pineal response types in the frog's brain under white light exposure

1979 ◽  
Vol 36 (1) ◽  
Author(s):  
J. Cadusseau ◽  
F. Gaillard ◽  
G. Galand
Keyword(s):  
White Light ◽  
Light Exposure

scholarly journals The Influence of Light Exposure in Ambiance during Pregnancy in Maternal and Fetal Outcomes: An Experimental Study

2018 ◽  
Vol 41 (01) ◽  
pp. 024-030
Author(s):  
Vitor Sarri ◽  
Beatriz Ferrari ◽  
Larissa Magalhães ◽  
Paula Rodrigues ◽  
Almir Rezende ◽  
...  
Keyword(s):  
Light Exposure ◽  
Good Practice ◽  
Histological Evaluation ◽  
Reproductive Parameters ◽  
Anthropometric Measures ◽  
Dark Light ◽  
Mean Values ◽  
Lighting Conditions ◽  
Significant Difference ◽  
Environmental Lighting

Objective The aim of this study is to evaluate whether exposure to different environmental lighting conditions affects the reproductive parameters of pregnant mice and the development of their offspring. Methods Fifteen pregnant albino mice were divided into three groups: light/dark, light, and dark. The animals were euthanized on day 18 of pregnancy following the Brazilian Good Practice Guide for Euthanasia of Animals. Maternal and fetal specimens were measured and collected for histological evaluation. Analysis of variance (ANOVA) test was used for comparison of the groups considering p ≤ 0.05 to be statistically significant. Results There was no significant difference in the maternal variables between the three groups. Regarding fetal variables, significant differences were observed in the anthropometric measures between the groups exposed to different environmental lighting conditions, with the highest mean values in the light group. The histological evaluation showed the same structural pattern of the placenta in all groups, which was within the normal range. However, evaluation of the uterus revealed a discrete to moderate number of endometrial glands in the light/dark and light groups, which were poorly developed in most animals. In the fetuses, pulmonary analysis revealed morphological features consistent with the transition from the canalicular to the saccular phase in all groups. Conclusion Exposure to different environmental lighting conditions had no influence on the reproductive parameters of female mice, while the offspring of mothers exposed to light for 24 hours exhibited better morphometric features.

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