Keeping a sleep diary is an important first step to improving your child's sleep. You can us ethe diary to note down what your child has been doing during the day, and how they sleep afterwards. This allows you to see whether different activities help or hinder a good night's sleep.
Source: 'Sleep and your Special Needs Child' Antonia Chitty and Victoria Dawson
To stimulate memories for someone with dementia, first work out what items may hold special significance for that person. Did they play a sport? An instrument? Spend a lot of time in the kitchen? The garden? Then collect relevant items in one location - a memory box, so they're easy to pull out.
Have the person with dementia hold each item and encourage them to share what that object brings to mind. You can talk about how it feels and what memories they associate with it.
The possibilities for what you might place in a memory box are endless. Use your creativity to create a memory-stimulating collection of items customised specifically to the person with dementia.
The following slides may hopefully give you some ideas.