See for instance this review of a new book on Reuters, How God (or more precisely, meditation) changes your brain.
But we don't hear anything about what the regular daily recitation of prayer does for your brain.
Unless of course we extrapolate from the article in today's Times, "Brain Is a Co-Conspirator in a Vicious Stress Loop." The research it describes makes a link between stress and repetitive activity, saying that one leads to the other.
...Why should the stressed brain be prone to habit formation? Perhaps to help shunt as many behaviors as possible over to automatic pilot, the better to focus on the crisis at hand. Yet habits can become ruts, and as the novelist Ellen Glasgow observed, “The only difference between a rut and a grave are the dimensions...”Made us start to think, yes the research shows a connection, but what if the repetitive activity helps to trigger or prolong the stress?
We do know people who claim that going to synagogue for regular prayer makes them nervous.