電子メディア教材における画質高度化の必要性について : 高品位映像教材の開発について(その1)

We examined the difference of the effects of different format video media to the human brain function by means of brain electric activity measuring method we have developed. As the visual materials for evaluation, three materials recorded by high definition (HD) video format, which has the highest visual quality now in practical use, were chosen and edited to the test pieces. Subsequently, they were down-converted to NTSC video format. On the presentation of visual images, we set three sound condition ; the music rich in natural high frequency components above the audible range (full-range sound), the same sound but from which high frequency components above 26kHz were eliminated (high-cut sound), and no sound. As a resullt, when the HD video were presented, the average of α-EEG (electroence-phalogram) potentials were significantly higher than NTSC video (p<0.05, post hoc test with Fisher\u27s PLSD). When we used the video of natural materials, the difference of a-EEG potential between HD presentation and NTSC presentation showed statistically significance. Although no significant difference in α-EEG was observed by using the more artificial visual material. When the video were presented with full-range sound, the average of α-EEG potential were significantly higher than the presentation with high-cut sound as well as no sound. These results showed that the quality of electric visual information could be evaluated by the α-EEG potential, which is the physiological and quantitative index of brain activity. It was also suggested that the improvement of the audio-visual format would be effective for the higher education