there was a study done in which a scientist used electromagnetic currents to give subjects feelings similar or identical to those experienced in reported "religious experiences."
There have been studies like this for decades. The most famous ones, and certainly the ones that were the most fun, involved giving subjects LSD in a controlled environment.
The study was not done to disprove the existence of any religion. In fact, they claim that "we have not attempted to refute or to support the absolute existence of gods, spirits, or other transient phenomena that appear to be prominent features of people's beliefs about themselves before and after death... However, we have shown that the experience of these phenomena, often attributed to spiritual sources, can be elicited by stimulating the brain with specific weak complex magnetic fields."
However, this information is almost always cited as proof that there is no God and that religious experience is false. It is a simple fact that this is not proof that God does not exist. However, it is evidence. It is evidence that there is no God and that religious experience is a delusion. In other words, based on the results of this and similar studies, we cannot conclude that there is no God. We can only conclude that is it less likely than we thought. How much less? I don't know. Even Richard Dawkins can't put an exact number on it. But this does give us reason to doubt.
I think the reason that this is taken as proof of God's non-existence is because of the false assumption that God, if He exists, works exclusively through mystical, abstract, non-physical means, but this is not a Christian doctrine. The Atheist demands magic. The Christian is comfortable with chemicals. The Atheist demands that God operate entirely outside of our bodies. The Christian is comfortable with religious experience being just that — an experience, and thus experimental. The idea that God doesn't always work through ridiculous violations of the laws of physics, but through natural processes, is not new the Christians.
Furthermore, you cannot prove that something does not exist simply because you can replicate it. If this were true, then we could conclude that there is no Federal Reserve because people fake counterfeit money. We could say that there is no such thing as love because there is Ecstasy. There are no natural lakes because there are man-made lakes.
The existence of a counterfeit does not indicate that it is not based on something authentic. It only means we need to be more careful before coming to conclusions about what is true or false, because even if there was a God, a good percentage of religious experiences must still be false.