Analysis of factors that bring mental effects to elderly people in robot assisted activity

We have developed mental commit robots that can provide psychological, physiological and social effects to human beings through physical interaction. The appearances of these robots look like real animals such as cats and seals. We have applied the mental commit robots to assist activities of the elderly people at a day service center. In order to investigate the effect of the robots on the elderly people, and to analyze the factors that influence them, we evaluated elderly people\´s mood by questionnaires, and investigated their experience of breeding pets, interaction with the robots and so on. The mental commit robots were introduced at the day service center for five weeks. Results show that the feelings of the elderly people were improved by interaction with the robots. As for the analysis of factors that bring mental effects to the elderly, we found the "time of touch divided by number of touch" in 2^nd week, and "experiences of breeding pets" in 5^th week. We conclude that mental commit robots are useful at elderly institutions like the day service center, and the factors of mental effects on elderly people changed from freshness of stimuli of the robots to feelings of breeding the robots like real animals.