I am taking an online course through Coursera on Philosophy, Science and Religion. In the first week, Dr. Sara Lane Richie gives a series of lectures on religious belief and embodiment, with a focus on recent studies in cognitive science. This flows remarkable well, I think, from my previous post on Testimony and the Spiritual Experience.
In these lectures, Dr. Richie reviews studies which show that religious experiences are accompanied by repeatable and measurable brain activity in the subject. And poses the question as to whether these studies disprove the claim of a spiritual experience.
While many atheists will likely claim that such studies do debunk claims of spiritual experiences, Dr. Richie rightly concludes that such studies merely show a correlation between brain activity and spiritual experiences, and do nothing to reveal the cause of such experiences. Why shouldn’t spiritual experiences be accompanied by brain activity? Would it not be even more surprising if there were no unique brain activity at all during such experiences?
And as a result, cognitive science will likely never be able to provide any insight into the source of the religious experience, nor be able to determine if spiritual experiences are “real”.
Eric Nielson
Small and Simple 
A couple of questions: 1) If brain activity during spiritual activities were caused by a Holy Spirit, would you expect some consistency in which regions of the brain are affected? (For example, brain activity is quite different between mindfulness meditators and those doing centering prayer.)
2) What if scientists could induce “spiritual” experiences that were identical to what people experience during their spiritual practices? If “spiritual” experiences can be induced, wouldn’t that imply that they are a function of the brain, not the Spirit?
A couple of attempts at answers: 1) I do not think we have any basis whatsoever to expect anything. Spirit could work however it needs on a case-by-case basis I suppose.
2) Such an inducement should not imply anything regarding how spirit may work. Goes back to correlation should not imply causation.