Atheist attack-dog Sam Harris has produced an interesting brain study that appears to show that we "believe" in objective truths such as 2+2=4 in much the same way we "believe" in aliens or maybe . . . God? That's the subject of his next study.
http://www.time.com/time/health/article/0,8599,1694723,00.html?xid=site-cnn-partner