Psychological and Physiological Influences of CCTs on Young People before Sleep

Zixin Weng,Li Zhou,Minchen Wei,Yandan Lin. 2017 14th ChinaInternational Forum on Solid State Lighting: International Forum on WideBandgap Semiconductors China (SSLChina: IFWS)105-108

Abstract:

This research studied the psychological andphysiological impacts of different lighting conditions on young people beforesleep. Young people were recruited as subjects aged from 21 to 25. Theexperiment had three lighting conditions with the same illuminance at 50lx, andthe correlated color temperatures (CCT) are 2700K, 4000K and 6500K. Subjectivequestionnaire was used to compare the young people's feelings about the light,while physical parameters such as heart rate, blood pressure and electroencephalograph(EEG) signal were recorded under different lighting conditions. The result ofthe questionnaire showed 2700K was the most relaxing light for sleep. Analysisof the physical parameters showed there's no significant different for heartrate or blood pressure between different color temperatures. Results alsoshowed the reductions of EEG in α frequency band under all three lightingconditions, and the 2700K had the most significant reduction of α wave. Bothsubjective results and objective results suggested low color temperature wouldbe more suitable for relaxation and sleep.