Okamoto Yosuke, Nakagawa Seiji
Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.
Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.
Physiol Behav. 2015 Jan;138:313-8. doi: 10.1016/j.physbeh.2014.10.013. Epub 2014 Oct 20.
Exposure to light modulates not only human alertness but also cognitive functions. The present study examined the temporal dynamics of the effects of light exposure on cortical activity related to cognitive processes. Event-related potentials (ERPs) were measured while participants performed an auditory oddball task during exposure to short-, medium- or long-wavelength light or darkness. Experiments were conducted in the daytime. After a 10-min period of darkness, one of the three lights was presented for 28 min. In the control condition, darkness was maintained for the entire session. The ERP component observed approximately 300 ms after the onset of the target stimulus (P300) was analyzed. The amplitude of P300 was larger after 5-20 min of exposure to short-wavelength light than at equivalent time points in the darkness. No differences were observed in the amplitude of P300 between the medium- or long-wavelength light condition and darkness at any time point. These results suggest that the amount of attentional resource allocated to the oddball task was increased by daytime exposure to short-wavelength light, and that following approximately 5 min of exposure the impact of light on cortical activity related to cognitive processes was able to be detected.
暴露于光不仅会调节人类的警觉性，还会影响认知功能。本研究考察了光暴露对与认知过程相关的皮层活动影响的时间动态变化。在参与者于短波长、中波长或长波长光或黑暗环境中执行听觉Oddball任务期间，测量其事件相关电位（ERP）。实验在白天进行。在10分钟的黑暗期后，呈现三种光中的一种，持续28分钟。在对照条件下，整个实验过程都保持黑暗。分析了在目标刺激开始后约300毫秒观察到的ERP成分（P300）。与黑暗环境中相同时间点相比，暴露于短波长光5 - 20分钟后P300的波幅更大。在任何时间点，中波长或长波长光条件与黑暗环境下P300的波幅均未观察到差异。这些结果表明，白天暴露于短波长光会增加分配给Oddball任务的注意力资源量，并且在暴露约5分钟后，能够检测到光对与认知过程相关的皮层活动的影响。
