Doing just 12 minutes of Kirtan Kriya research has shown reduces mental aging and may help reduce Alzheimers. The article below both gives the research and step by step instructions on how to do the meditation

Conclusion: The Kirtan Kriya singing exercise reverses memory loss and enhances brain function. This study provides fertile ground for further long-term research on the measurement and research of memory loss.From http://www.alzheimersprevention.org/research.htm

Video about Kirtan Kriya and demo of how to do it below