Periods of wakefulness / sleep, will be studied using an actimeter the Vivago device (STI International) which is in the form of a wristwatch worn on the wrist of the non-dominant person and contains an accelerometer. The activity meter measures and records the full range of motion achieved for 60 consecutive seconds and transmits the measured value every minute radio frequency to a base connected to a computer that records real-time values. A computer application to detect with good reliability sleep periods based on the analysis of movements and their amplitude and has been validated by laboratory studies in healthy people of all ages. This same device was also used to study the circadian rhythms in patients with dementia and non-dementia in nursing homes, so it seems quite usable in demented patients. This system collects the total sleep time, and periods of revival / night activity. For cons, the use of this device to record and quantify motor agitation is a new approach that has never been developed known. This exploratory approach will require several experimental treatments of data to identify the most relevant parameters in the context of the analysis of the range of motion. Schematically, the study will focus on the amplitude schedule of movements, but also on the frequency of movement exceeding a certain threshold amplitude. Finally, the variation in the test more than inter-individual differences will be studied in particular.