2012年に、プラセボやノセボを、意図的な認識によらずに、無意識に形成しうるという研究が発表されている。[Placebo Response Occurs at Nonconscious Level: Findings Demonstrate Unconscious Mind Plays a Key Role in Pain Experiences (2012/09/10) on ScienceDaily] However, more recently, scientists have recognized that humans learn to expect either reward or threat quickly and automatically without needing to consciously register the idea in their brains.
