I’m a full-blown atheist. My dad died a couple of years ago and I “talk” to him frequently simply because I’m accustomed to doing it and it’s a nice thing to imagine. I know full well that there’s no magical way he’s still around and listening to me, but humans gonna human and there’s nothing wrong with having quirks like that.

I recall reading a study a long time back where researchers put people in fMRI machines to monitor their pattern of brain activity and then asked them to consider some kind of ethical question. Some of the subjects were told to talk to an attendant who was physically present, some were told to talk to themselves about it, and some were told to talk to whatever deity they believed in about it. The brain activity patterns for talking to someone physically present were different from the brain activity patterns for talking to oneself, but the activity patterns for talking to oneself and talking to God were identical. It was a neat result.

Edit: It’s not exactly as I remembered it, but given how human memory works I bet this is the article I was thinking of.