 |
The Journal of Neuroscience, May 15, 2003, 23(10):4315-4323
Previous Article | Next Article 
Conscious Expectation and Unconscious Conditioning in Analgesic, Motor, and Hormonal Placebo/Nocebo Responses
Fabrizio Benedetti,1,2
Antonella Pollo,1,2
Leonardo Lopiano,1
Michele Lanotte,4
Sergio Vighetti,1 and
Innocenzo Rainero1,3
1Department of Neuroscience, University of Turin Medical School, Turin, Italy 10125,
2Department of Clinical and Applied Physiology Program, University of Turin Medical School, Turin, Italy 10125,
3Department of Neurology IIIHeadache Center, University of Turin Medical School, Turin, Italy 10125, and
4Division of Neurosurgery, CTO Medical Center, Turin, Italy 10126
The placebo and nocebo effect is believed to be mediated by both cognitive and conditioning mechanisms, although little is known about their role in different circumstances. In this study, we first analyzed the effects of opposing verbal suggestions on experimental ischemic arm pain in healthy volunteers and on motor performance in Parkinsonian patients and found that verbally induced expectations of analgesia/hyperalgesia and motor improvement/worsening antagonized completely the effects of a conditioning procedure. We also measured the effects of opposing verbal suggestions on hormonal secretion and found that verbally induced expectations of increase/decrease of growth hormone (GH) and cortisol did not have any effect on the secretion of these hormones. However, if a preconditioning was performed with sumatriptan, a 5-HT1B/1D agonist that stimulates GH and inhibits cortisol secretion, a significant increase of GH and decrease of cortisol plasma concentrations were found after placebo administration, although opposite verbal suggestions were given. These findings indicate that verbally induced expectations have no effect on hormonal secretion, whereas they affect pain and motor performance. This suggests that placebo responses are mediated by conditioning when unconscious physiological functions such as hormonal secretion are involved, whereas they are mediated by expectation when conscious physiological processes such as pain and motor performance come into play, even though a conditioning procedure is performed.
Key words: expectation; conditioning; placebo; pain; Parkinson's disease; hormones
Received Dec. 2, 2002;
revised Jan. 31, 2003;
accepted Feb. 7, 2003.
This article has been cited by other articles:

|
 |

|
 |
 
D. Laverdure-Dupont, P. Rainville, J. Montplaisir, and G. Lavigne
Changes in Rapid Eye Movement Sleep Associated with Placebo-Induced Expectations and Analgesia
J. Neurosci.,
September 23, 2009;
29(38):
11745 - 11752.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Benedetti, M. Lanotte, L. Colloca, A. Ducati, M. Zibetti, and L. Lopiano
Electrophysiological properties of thalamic, subthalamic and nigral neurons during the anti-parkinsonian placebo response
J. Physiol.,
August 1, 2009;
587(15):
3869 - 3883.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Liu
Acupuncture: What Underlies Needle Administration?
Evid. Based Complement. Altern. Med.,
June 1, 2009;
6(2):
185 - 193.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. D. Lane, S. R. Waldstein, H. D. Critchley, S. W. G. Derbyshire, D. A. Drossman, T. D. Wager, N. Schneiderman, M. A. Chesney, J. R. Jennings, W. R. Lovallo, et al.
The Rebirth of Neuroscience in Psychosomatic Medicine, Part II: Clinical Applications and Implications for Research
Psychosom Med,
February 1, 2009;
71(2):
135 - 151.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. S. Oken
Placebo effects: clinical aspects and neurobiology
Brain,
November 1, 2008;
131(11):
2812 - 2823.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. M. Aslaksen and M. A. Flaten
The Roles of Physiological and Subjective Stress in the Effectiveness of a Placebo on Experimentally Induced Pain
Psychosom Med,
September 1, 2008;
70(7):
811 - 818.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
N. J. Diederich and C. G. Goetz
The placebo treatments in neurosciences: New insights from clinical and neuroimaging studies
Neurology,
August 26, 2008;
71(9):
677 - 684.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
O. Frenkel
A Phenomenology of the 'Placebo Effect': Taking Meaning from the Mind to the Body
J Med Philos,
February 1, 2008;
33(1):
58 - 79.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Benedetti, A. Pollo, and L. Colloca
Opioid-Mediated Placebo Responses Boost Pain Endurance and Physical Performance: Is It Doping in Sport Competitions?
J. Neurosci.,
October 31, 2007;
27(44):
11934 - 11939.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Benedetti, M. Amanzio, S. Vighetti, and G. Asteggiano
The Biochemical and Neuroendocrine Bases of the Hyperalgesic Nocebo Effect.
J. Neurosci.,
November 15, 2006;
26(46):
12014 - 12022.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. K. Vallance
Something out of nothing: the placebo effect
Adv. Psychiatr. Treat.,
July 1, 2006;
12(4):
287 - 296.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G J. Rubin, G. Hahn, B. S Everitt, A. J Cleare, and S. Wessely
Are some people sensitive to mobile phone signals? Within participants double blind randomised provocation study
BMJ,
April 15, 2006;
332(7546):
886 - 891.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Benedetti, H. S. Mayberg, T. D. Wager, C. S. Stohler, and J.-K. Zubieta
Neurobiological Mechanisms of the Placebo Effect
J. Neurosci.,
November 9, 2005;
25(45):
10390 - 10402.
[Full Text]
[PDF]
|
 |
|
|

|