Relief Without Belief
The dominant theories of placebo effects rely on a notion that consciously perceptible cues provide signals that activate placebo effects. ~ American psychiatrist Karin Jensen et al
An experiment conducted in 2012 highlighted the power of the mind to induce bodily states. Healthy participants were tested for placebo and nocebo effects by flashing images of faces, either happy (to test placebo) or in pain (to test nocebo). The image cues were only shown for 12 milliseconds: flashing too quickly for conscious recognition. Nonetheless, the suggestions subconsciously registered and produced effects.
A person can have a placebo or nocebo response even if he or she is unaware of any suggestion of improvement or anticipation of getting worse. ~ Karin Jensen