scholarly journals Effect of LED Lighting Illuminance and Correlated Color Temperature on Working Memory

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Chung Won Lee ◽  
Jin Ho Kim
Keyword(s):  
Working Memory ◽  
Standard Deviation ◽  
Repeated Measures ◽  
Memory Performance ◽  
Light Condition ◽  
Bright Light ◽  
Color Temperature ◽  
Led Lighting ◽  
Temperature Conditions ◽  
Lighting Conditions

This study was conducted to verify how the illuminance and correlated color temperature of LED lighting affect working memory. For this study, an automatic LED lighting device based on a light sensor was developed and used, and the lighting conditions were treated with a total of six conditions (2 × 3): two illuminance conditions (dim: 400 lx, bright: 1,000 lx) and three correlated color temperature conditions (3,000 K, 5,000 K, and 7,000 K). There were 30 participants in the study, and the average age was 21.6 years (Standard deviation = 1.92). Participants were assigned to all six lighting conditions, and the placement order was randomized. For the measurement of working memory, 3-back task was used and the correct responses for 5 minutes were used as a dependent variable. As a result of repeated measures analysis of variance (ANOVA), both illuminance and correlated color temperature were found to be significant variables affecting working memory, and no interaction effect between illuminance and correlated color temperature was found. As a result of the post hoc verification conducted thereafter, the working memory performance in the bright light condition (1,000 lx) was 48.32 (Standard deviation = 15.63) on average, compared to 44.80 (Standard deviation = 15.29) in the relatively dim condition (400 lx). It was found that the condition of bright light was superior in performing working memory compared to relatively dim condition. The working memory performance in the correlated color temperature condition (5,000 K) was 48.32 (Standard deviation = 16.41) on average and higher than that of other color temperature conditions. As a result, working memory performance was the best in 1,000 lx, 5,000 K condition Mean = 53.43 (Standard deviation = 18.38), and 400 lx, 7,000 K condition Mean = 42.73 (Standard deviation = 17.68) showed the worst performance of working memory.

scholarly journals Effects of Different Light Sources on Neural Activity of the Paraventricular Nucleus in the Hypothalamus

Medicina ◽  
2019 ◽  
Vol 55 (11) ◽  
pp. 732
Author(s):  
Michio Yokoyama ◽  
Hyukki Chang ◽  
Hiroshi Anzai ◽  
Morimasa Kato
Keyword(s):  
Paraventricular Nucleus ◽  
Neural Activity ◽  
Light Emitting Diode ◽  
Light Irradiation ◽  
Color Temperature ◽  
Light Sources ◽  
Led Lighting ◽  
Lighting Conditions ◽  
Different Color ◽  
Fluorescent Lighting

Background and Objectives: Physical function is influenced by light irradiation, and interest in the influence of light irradiation on health is high. Light signals are transmitted from the retina to the suprachiasmatic nucleus (SCN) via the retinal hypothalamic tract as non-image vision. Additionally, the SCN projects a nerve to the paraventricular nucleus (PVN) which acts as a stress center. This study examined the influences of three different light sources on neural activity in the PVN region using two different color temperatures. Materials and Methods: Experiments were conducted using twenty-eight Institute of Cancer Research (ICR) mice (10 week old males). Three light sources were used: (1) organic light-emitting diode (OLED) lighting, (2) LED lighting, and (3) fluorescent lighting. We examined the effects of light irradiation from the three light sources using two different color temperatures (2800 K and 4000 K). Perfusion was done 60 min after light irradiation, and then the brain was removed from the mouse for an immunohistochemistry analysis. c-Fos was immunohistochemically visualized as a marker of neural activity in the PVN region. Results: The number of c-Fos-positive cells was found to be significantly lower under OLED lighting and LED lighting conditions than under fluorescent lighting at a color temperature of 2800 K, and significantly lower under OLED lighting than LED lighting conditions at a color temperature of 4000 K. Conclusions: This study reveals that different light sources and color temperatures alter the neural activity of the PVN region. These results suggest that differences in the light source or color temperature may affect the stress response.

The Study of LED Lighting Color Temperature and Visual Effect

2013 ◽  
Vol 275-277 ◽  
pp. 2491-2494
Author(s):  
Ke Huang ◽  
Sha Sha He ◽  
Ming Gao
Keyword(s):  
Pupil Size ◽  
Light Attenuation ◽  
Color Temperature ◽  
Eye Tracker ◽  
Visual Effect ◽  
Led Lighting ◽  
High Rise ◽  
Lighting Conditions ◽  
Architectural Lighting ◽  
Background Brightness

The application of LED was in an exploring stage, while it had a series of problems on architectural lighting, such as light distribution, color temperature selection and light attenuation. Based on the relations between color temperature and visual effect, this thesis discussed the relations between three kinds of LED color temperature and the changes of human pupil size. In the circumstances of settled lighting conditions, adjust visual regional background brightness, the changes of pupil size was measured with the aid of iView eye tracker. The survey finds that the pupil shrinks with the high rise of light source color temperature, which leads to the improvement of visual efficiency. However, high color temperature appears dazzling, which is likely to cause fatigue and discomfort.

Shining light on memory: Effects of bright light on working memory performance

2015 ◽  
Vol 294 ◽  
pp. 234-245 ◽  
Author(s):  
L.M. Huiberts ◽  
K.C.H.J. Smolders ◽  
Y.A.W. de Kort
Keyword(s):  
Working Memory ◽  
Memory Performance ◽  
Bright Light ◽  
Memory Effects

The influence of LED lighting on task accuracy: time of day, gender and myopia effects

2017 ◽  
Vol 31 (19-21) ◽  
pp. 1740019
Author(s):  
Feng Rao ◽  
A. H. S. Chan ◽  
Xi-Fang Zhu
Keyword(s):  
Time Of Day ◽  
Color Temperature ◽  
Afternoon Session ◽  
Led Lighting ◽  
Location Task ◽  
Lighting Conditions ◽  
Significant Difference ◽  
Research Task ◽  
Task Accuracy ◽  
Marker Location

In this research, task errors were obtained during performance of a marker location task in which the markers were shown on a computer screen under nine LED lighting conditions; three illuminances (100, 300 and 500 lx) and three color temperatures (3000, 4500 and 6500 K). A total of 47 students participated voluntarily in these tasks. The results showed that task errors in the morning were small and nearly constant across the nine lighting conditions. However in the afternoon, the task errors were significantly larger and varied across lighting conditions. The largest errors for the afternoon session occurred when the color temperature was 4500 K and illuminance 500 lx. There were significant differences between task errors in the morning and afternoon sessions. No significant difference between females and males was found. Task errors for high myopia students were significantly larger than for the low myopia students under the same lighting conditions. In summary, the influence of LED lighting on task accuracy during office hours was not gender dependent, but was time of day and myopia dependent.

Short- and long-term memory tasks predict working memory performance, and vice versa.

2019 ◽  
Vol 73 (2) ◽  
pp. 79-93 ◽  
Author(s):  
Ian Neath ◽  
Jean Saint-Aubin ◽  
Tamra J. Bireta ◽  
Andrew J. Gabel ◽  
Chelsea G. Hudson ◽  
...  
Keyword(s):  
Working Memory ◽  
Memory Performance ◽  
Long Term Memory ◽  
Term Memory ◽  
Short And Long Term

How Does Caffeine Impact Working Memory Performance in Extraverts and Introverts?

2012 ◽  
Author(s):  
Jaclyn Jansen ◽  
Gabriella Dimotsantos ◽  
Marian E. Berryhill
Keyword(s):  
Working Memory ◽  
Memory Performance
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