Objectives: Selecting suitable illumination is an integral part of increasing productivity in the office or factory, because poor lighting conditions may often cause decreased work efficiency. Light emitting diode (LED) light is becoming recognized as one of the most promising general sources of illumination. We conducted spectral power analysis of electroencephalograms (EEGs) obtained during resting and cognitive task activities to identify the effects on human arousal and cognitive performance under LED light compared with conventional fluorescent light. Methods: Thirteen healthy, right-handed students participated in the present study. Each subject took part in two experimental sessions, one under fluorescent and one under LED lighting conditions. The experimental measurements consisted of a resting state EEG, an event-related potential (ERP) during a visual working memory (VWM) task, and a questionnaire about subjective feelings regarding the lighting conditions. The EEG power spectra, the amplitude and latency of the P300 ERP component, the behavioral responses for the VWM task, and the questionnaire data were compared for the two lighting conditions. Results: The EEG spectral power showed no difference between the LED and fluorescent lighting conditions. The amplitude of the P300 component decreased significantly with increasing numbers of items, while there were no differences between the two lighting conditions. Additionally, behavioral responses and subjective feelings were the same under the two lighting conditions. Conclusions: Our study suggests that there are no significant differences between LED light and fluorescent light on the human arousal state and VWM. J Korean Sleep Res Soc 2012;9:28-33
Objectives: Vertex wave during sleep is a hallmark of light sleep and related to brain development. We examined voltage characteristics of vertex wave according to age. Methods: Electroencephalographys were selected from routine waking and sleep EEG database. The inclusion criteria were that the age of subjects was more than 4 years old; EEG showed at least 5 typical vertex waves with no abnormal findings; the neurologic examination and neuroimaging findings were normal. EEGs were classified into 7 groups according to their age. Five to 20 epochs which included the time 320 ms before and after the maximum negativity of a vertex wave from each EEG record were selected. Voltage characteristics including amplitude and topographic distribution were evaluated. Intracerebral source location of vertex wave from each age group was identified using low resolution electromagnetic tomography (LORETA). Results: Amplitude of vertex wave was highest in the youngest age group, decreased with age thereafter. Voltage topography showed maximum negativity over central vertex area bilaterally in all age group, which did not show any significant difference among age group. Normalized amplitude of vertex waves showed significant main effect of location (df=1.356, F= 115.843, p<0.001). Interaction between age and location was also significant (df=4.088, F=3.327, p=0.016). However, age did not show any main effect on amplitude of vertex wave. Post-hoc analysis showed amplitude of group 1 (5 to 9 years), compared with other age groups, was significantly lowered only in Fz electrode. LORETA image showed maximum current density in the mid to posterior cingulate gyri, which was similar across all age groups. Conclusions: Our study suggests that vertex waves might be related to arousal response during sleep, although exact mechanism is still unclear.J Korean Sleep Res Soc 2012;9:5-9
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.