Pilot experimental study; Effect of environmental stimulation consisting of sound with high-frequency components, aromas, and light exposure from organic light-emitting diodes (OLEDs) toward rest-activity rhythm in institutionalized patients with dementia

Environmental stimulation is expected to have a positive impact on night sleep, psychological or functional states in dementia. The objective of this pilot study was to examine the effects of environmental stimulation consisting of sounds with high-frequency components, aromas, and light exposure from organic light-emitting diodes (OLEDs) to create comfortable living spaces for persons with dementia. Subjects (n =6) were recruited from elderly persons admitted to a single nursing home in Akita Prefecture, Japan, between August and September 2020. The night-time sleep state, the rest-activity rhythm, and the light exposure of the subjects living in environments with or without environmental stimulation consisting of sounds with high-frequency components, aromas, and light exposure from OLEDs were measured for 46.3 consecutive days using wrist activate devices under free-living conditions in a nursing home. In a period of environmental stimulation depending on the presence or absence of sounds with high-frequency components, reduction of the fragmented rest-activity rhythms was significantly observed in the subjects (p < 0.05). However, changes in the night-time sleep state had no significant difference during the study period. In conclusion, these preliminary results suggest that future examinations are warranted not only to inform effective or comfortable living conditions for elderly persons with dementia but also to improve the disruption of rest-activity rhythms in persons with dementia.