One of the grand social challenges that developed countries are facing in the 21st century is the problem of an ageing population. This holds in particular for countries with small populations like New Zealand. People expect to live longer than ever before, and they expect that this increased longevity will be enjoyed living an independent, high quality lifestyle in their own homes. Unfortunately this expectation is not always met. Diminished mental capabilities, caused by age or diseases such as Alzheimer’s or Parkinson’s, often require supervision of some sort – a demand society finds more and more difficult to satisfy. Artificial intelligence offers a solution to this problem. It can provide methods that will eventually be used in a smart home as a cognitive prosthesis for the elderly by detecting abnormal, potentially harmful behaviour and alerting a carer if a critical situation arises. This talk will provide an insight into some of these methods and discusses their strengths and shortcomings.