"Placebos can influence health outcomes, but, it has not been clear how this happens. Recent posts have described how mental activity, such as expectations, determine perception, rather than just physical sensory information. Now, placebos demonstrate that perception alters physical health. Research shows that diverse brain regions are involved, including stimulation of natural opiod neurotransmitters and dopamine. Most of the research addressing these mechanisms has been related to placebo affects on pain, which have been the easiest to study."