More than a third of us admit to having had a spiritual experience. We might have been profoundly moved by a sunset or a painting; or felt that we've connected with our god or with the entire world around us. Such events can be transformative - bringing positive change to our lives and increasing our happiness - but some experiences aren't so great. 

In front of a live audience in Washington DC, David Yaden of Johns Hopkins University tells Dr Laurie Santos about his work examining what effect spiritual experiences have on us and how things like meditation and psychedelic drugs can bring about these powerful transformational episodes.  

David Yaden is the author of: The Varieties of Spiritual Experience: 21st Century Research and Perspectives.