*6.2. Participants*

Thirty elderly residents in a nursing home participated in the trial: 26 females and 4 males. They were native Japanese speakers. Their average age was 86.3 years (SD = 7.5). According to caregivers, 13 participants had no dementia, 4 had mild dementia, and the other 13 had advanced dementia.

The participants were recruited by caregivers of the nursing home. Before the trial, we explained the purpose and the procedure to the caregivers and asked them to recruit candidates who would like to participate in the trial. We sent an instruction document of the trial to their families and asked the families to fill out a consent form. The consent form had been approved by the ethical committee of Osaka University. The candidates whose families agreed that they should participate in the trial became the participants.

Furthermore, two caregivers participated in the trial to observe participants' behavior.
