RT Journal Article SR Electronic T1 Manipulation of Expectancy and Anxiety in Placebo Research and Their Effects on Opioid-Induced Analgesia JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 14051 OP 14052 DO 10.1523/JNEUROSCI.3756-12.2012 VO 32 IS 41 A1 Maike Mueller A1 Espen Bjørkedal A1 Sandra Kamping YR 2012 UL http://www.jneurosci.org/content/32/41/14051.abstract AB