Copyright© 2017 All Rights Reserved. J-STAGE 2018.02.09 Transactions of Japan Society of Kansei Engineering J-STAGE Advance Published Date: 2018.02.09 doi: 10.5057/jjske.TJSKE-D-17-00030 1. , 1 2 REM REM 3-6 7-9 7 10 8 Psychophysiological Study of Effect of Emotion in Sleep Onset Process by Using Hypnagogic Imagery Hiromichi TAKEHARA*, Hideki TANAKA** and Tatsuya IWAKI** * Graduate School of Medic