Assessment of brainwave on LED billboard video by EEG

• Main Authors: Hung Li, 李弘
• Other Authors: Tsung-xian Lee
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/55620449814091037567

碩士 === 國立臺灣科技大學 === 色彩與照明科技研究所 === 103 === The influence of the RGB LED signage and large-format displays on our cognitive-performance seems to be more critical in the modern life. Discomfort glare is one of nuisances, wherein, most people walk or drive in urban area at night. In recent years, brainwave has been paid attention to medical research. Brainwaves are produced by synchronized electrical pulses from masses of neurons communicating with each other. From the earlier research, we understand that people's brainwaves will change as delighted, depressed, nervous, pay attention or work etc. Research has also identified brainwave patterns associated with all sorts of emotional and neurological conditions. This study aims is to explore the brainwave of the screen luminance and exposed time as watching motion pictures on a RGB LED large-format display (LFD) by using electroencephalogram (EEG). Twenty subjects ranged from 21 to 60 years old who were normal color vision and normal vision included were recruited to participate in the experiments. Each subject attended 6 experimental sessions. In each session, a different set of viewing conditions was applied. The viewing parameters included 2 levels of LED billboard (1000 cd/m2, 5000 cd/m2) and 3 exposed time (60sec, 120sec,180 sec), and each session was presented in a random order to each subject. Each subject assessed the same 10 video clips in each session. In total, they assessed 60 clips. For each clip, the subject rated his or her discomfort glare using the de Boer scale. Subject rated one condition during the video playing. Meanwhile, The EEG power spectrums of alpha waves and beta waves of the participant were recorded by a commercial device. The device’s reference and ground electrodes are on the ear clip and the EEG electrode is on the sensor arm, resting on the forehead above the eye (FP1 position). The process was repeated until all clips of one session were presented. In average, each session took about 20 minutes. The experiment was based on a randomized factorial design with measures on 3 factors including luminance of LED LFD, exposed time and video. Results revealed that the main effect of luminance of LED was significant. The beta waves were inhibited as increasing the luminance of LED. And the alpha waves were slight decreased at the high luminance level. Results also demonstrated that alpha, beta waves and attention were decreased as the long exposed time. Therefore, attention will be decreased causing visual fatigue during the test. However, brainwave and cognitive evaluation are not significant related. Therefore, we have the improvement on objective measurement with brainwave. We suggested the further refinement of the experiment parameters and subsequent exploration of cognitive-modulation. It will be necessary to facilitate our cognitive of discomfort glare.