Several studies have shown that Kirtan Kriya helps on reducing risk factors for Alzheimer's disease and the enhancement of total brain fitness. I'd like to share with you the following article published by Dharma Singh Khalsa, M.D. in The Huffington Post about Kirtan Kriya and braing health. Please click here.
3HO.org is an awesome place to find resources about Kundalini Yoga as taught by Yogi Bhajan. You can find how to practice Kirtan Kriya clicking on this link or downloading this PDF file.
There are multiple YouTube videos showing how to practice this kriya. Below it is an example.
Hope this meditation helps you to be healthier, happier and holier. Sat Nam.