What kind of light can improve people's alertness?

LED semiconductor lighting network information is in different light environments, our vitality, mood, alertness performance is not the same, in addition to their individual differences, lighting intensity as one of the most important light parameters also have an important impact. In daily work, as work time goes on or work tasks increase, we will feel mental fatigue and blurred vision. Such emotions will make people more and more sleepy, lack of concentration, psychological pressure gradually increase, and negative on work performance. influences.

Apathy during working hours can also affect other rest periods, which can also adversely affect the rhythm of the body. If we are just working in a warm, soft or gloomy light environment, fatigue may come faster. Indoor lighting affects people's cognitive performance through emotions, so what kind of light can improve people's alertness.

The human eye can see that it is a very complicated physiological process. The specific formation process of vision includes: light → cornea → pupil → lens (refracted light) → vitreous (fixed eyeball) → retina (formation of image) → optic nerve (conductive visual information) → Brain vision center (formation of vision). Photoreceptors can be divided into two major categories according to their shape, namely rod cells and cone cells. Under different light intensities, these two types of cells have different effects. When the ambient brightness level is greater than 3 cd/m2, the cone-shaped cells mainly act, and when the brightness level is lower than 0.00lcd/m2, the rod-shaped cells mainly produce a visual effect.

In 2002, Professor Berson of the United States discovered through experiments that there is indeed a third type of photoreceptor cells in the retina of mammals - retinal specialized photoreceptor ganglion cells. When light enters the human eye and is received by such photoreceptor cells, it produces a photobiological effect. From this level, the intensity of light can directly and indirectly affect the biological clock, directly affecting the instantaneous changes including physiological awakening, and the indirect influence refers to the rhythm. Periodic changes.

Karin CHJ Smolders's experiments on brightness and mental fatigue indicate that higher illumination levels can produce better mental performance as an illumination source, and are more alert than low illumination conditions. The experiment required the subjects to be under two experimental conditions:

1. Fatigue conditions

2. The general control conditions are studied under the conditions of two illuminances of 200lx and 1000lx.

Participants came to the lab four times in the same time period, in the morning (9:00am, 10:20am or 11:45am), or in the afternoon (13:15pm, 14:45pm or 16:15pm).

Each set of experiments has a seven-minute baseline phase, and a 29-minute mental fatigue vs. control manipulation. The illumination of the working surface is 200 lx and 1000 lx, the color temperature is 4000 K, and then exposed to the experimental light. 30 minutes under the environment.

The results showed that under the premise of different mental states of the subjects, the high illumination conditions had an impact on the subjects' subjective and objective alertness, judgment and awakening. In a state of fatigue (ie, fatigue), a bright lighting environment can reduce people's sleepiness and improve people's self-discipline, improve alertness and vitality, thereby playing a positive role in task performance, and can also reduce sleep. Subjective fatigue caused by insufficient. The optimization of the lighting parameters is beneficial to the improvement of cognition and the improvement of a more pleasant light environment.

Figure: Under the condition of 200lx illumination, the degree of fatigue and difficulty with the experiment

Figure: Under 1000lx illumination, the degree of fatigue and distress with the experiment

Figure: Vitality with the experiment under 200lx illumination

Figure: Vitality with the experiment under 1000lx illumination

The article points out that if high illumination affects people's feelings, performance and physiological influences on the previous mental state, the illumination intensity has a more significant and timely effect on the subjects who are in a tired working state, and the opposite is the resting state. The trial effect is slow and not obvious. The experiment provides that the light environment is an artificial light source, and there is no daylight component, and there are only two illumination setting conditions. The daylight condition includes a very wide range of illumination, corresponding to a more complex range of alert performance.

in conclusion:

There is an interaction between mental state and lighting level and heart rate changes in the original work performance. In addition to the potential impact of light intensity on alertness and excitement, the subject's assessment of the light environment is also considered. Measuring the familiarity of the environment space and personal personality, there is a certain functional relationship between lighting conditions and their emotional changes. What is certain is that within a certain range of illumination, a bright light environment can increase people's alertness and reduce sleepiness caused by work tasks or lack of sleep.