En rekke studier viser at placeboeffekten har direkte innvirkning på andre deler av hjernen og viser hvordan kognitiv forventning påvirker den nevrokjemiske funksjonen. Dette vises ved blant annen ulik billeddiagnostikk.( Petrovic P, Kalso E, Petersson KM, Ingvar M (2002) Placebo and opioid analgesia—imaging a shared neuronal network. Science 295: 1737-1740; Wager TD, Feldman Barrett L (2004) From affect to control: functional specialization of the insula in motivation and regulation. PsycExtra, Zubieta JK, Bueller JA, Jackson LR, Scott DJ, Xu Y, Koeppe RA, Stohler CS (2005a) Placebo effects mediated by endogenous opioid neurotransmission and μ-opioid receptors. J Neurosci 25: 7754-7762.; Zubieta JK, Bueller JA, Jackson LR, Scott DJ, Xu Y, Koeppe RA, Stohler CS (2005a) Placebo effects mediated by endogenous opioid neurotransmission and μ-opioid receptors. J Neurosci 25: 7754-7762.; Wager TD, Scott DJ, Zubieta JK (2007) Placebo effects on human mu-opioid activity during pain. Proc Natl Acad Sci U S A 104:11056–11061.; Eippert F, Bingel U, Schoell ED, Yacubian J, Klinger R, Lorenz J, Büchel C (2009b) Activation of the opioidergic descending pain control system underlies placebo analgesia. Neuron 63:533–543. Watson A, El-Deredy W, Iannetti GD, Lloyd D, Tracey I, Vogt BA, Nadeau V, Jones AKP (2009) Placebo conditioning and placebo analgesia modulate a common brain network during pain anticipation and perception. Pain 145:24–30.; Lui F, Colloca L, Duzzi D, Anchisi D, Benedetti F, Porro CA (2010) Neural bases of conditioned placebo analgesia. Pain 151:816–824.; Wager TD, Atlas LY, Leotti LA, Rilling JK (2011) Predicting individual differences in placebo analgesia: contributions of brain activity during anticipation and pain experience. J Neurosci 31:439–452.; Wager TD, Fields H (2011) in Wall and Melzack’s textbook of pain, Placebo analgesia, eds McMahon SB, Koltzenburg M (Churchill Livingstone, Oxford) In press, Ed 6.; Krummenacher P, Candia V, Folkers G, Schedlowski M, Schönbächler G (2010) Prefrontal cortex modulates placebo analgesia. Pain 148:368–374.;)
