An artical in this months New Scientist magazine showing that buddhists can affect there own level of happyness by medatation not only during the time that they are medatating but also in the long term,
"Activity in the left prefrontal lobe indicates positive emotions and good mood, whereas persistant activity in the right prefrontal lobes indicates negative emotion. The first Buddhist practitioner studied by Davidson showed more left prefrontal lobe activity than anyone he had ever stuided before"
And so on.