Latent inhibition of rotation chair-induced nausea in healthy male and female volunteers.
OBJECTIVE
Pre-exposure to an environment in which a nausea-inducing body rotation will subsequently be given constitutes a latent inhibition procedure that might act to reduce anticipatory and postrotation nausea.


METHODS
This was tested in 24 healthy subjects randomly assigned to receive no pre-exposure (group 0), a single pre-exposure (group 1), or three pre-exposures (group 3). Rotation was standardized as 5 x 1 minute rotation, but the subjects could terminate it on request. Nausea was determined on a 7-item symptom rating scale before, during, and after rotation on days 3 and 4, whereas anticipatory nausea was measured before presumed rotation on day 5. Saliva cortisol and tumor necrosis factor alpha (TNF-alpha) levels were determined at baseline before, directly, and 15 and 30 minutes after rotation every day, and before presumed rotation on day 5.


RESULTS
Pre-exposure significantly reduced the degree of anticipatory nausea on day 5. Cortisol levels increased with rotation and were higher at baseline on days 4 and 5, but subjects habituated from day 3 to day 4; levels were lower in women than in men. In contrast, TNF-alpha decreased with rotation but showed no habituation. For both cortisol and TNF-alpha, no effects on postrotational nausea were found.


CONCLUSIONS
It is concluded that repetitive pre-exposure (latent inhibition) reduces anticipatory but not postrotation nausea; behavioral measures (rotation time) and measures of acute stress (cortisol, TNF-alpha) do not respond to latent inhibition. Thus, Pavlovian conditioning rules are effective in healthy humans with anticipatory nausea but not with postrotation nausea. Hormonal responses--TNF-alpha decrease with stress, compensatory cortisol increase--and gender-related effects on learning and habituation are discussed with regard to psychophysiological and psychoimmunological processes.
Klosterhalfen
Sibylle
S
Institute of Medical Psychology, University Hospitals Düsseldorf, Düsseldorf, Germany.
Kellermann
Sandra
S
Stockhorst
Ursula
U
Wolf
Jutta
J
Kirschbaum
Clemens
C
Hall
Geoffrey
G
Enck
Paul
P
D000328:Adult; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use; D003214:Conditioning, Classical / Q000502:physiology; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D009041:Motion Sickness / Q000209:etiology / Q000517:prevention & control; D009325:Nausea / Q000139:chemically induced / Q000517:prevention & control* / Q000523:psychology; D011187:Posture / Q000502:physiology*; D012399:Rotation / Q000009:adverse effects*; D012737:Sex Factors; D016896:Treatment Outcome; D014840:Vomiting, Anticipatory / Q000517:prevention & control / Q000523:psychology
D000970:Antineoplastic Agents; D006854:Hydrocortisone