This paper investigates the effect of nocebo suggestions on food craving levels and explores whether personality traits, specifically neuroticism and impulsivity, moderate this impact. The study...Show moreThis paper investigates the effect of nocebo suggestions on food craving levels and explores whether personality traits, specifically neuroticism and impulsivity, moderate this impact. The study was conducted using a sample of 21 volunteers which were recruited from Leiden University, and used a randomised controlled trial design. The two groups that were used in the analysis were control and nocebo groups (increase hunger). Nocebo group participants received a sham vagus nerve stimulation and were exposed to suggestions that this stimulation will increase their hunger. Food craving was measured using a Visual Analogue Scale at different time points throughout the experiment, and self-report inventories were used to assess neuroticism and impulsivity. A repeated measures Analysis of Variance (ANOVA) and a moderation analysis were performed to analyse the data. The results showed significant changes in craving intensity, F(3, 57) = 11.14, p < .001, with higher craving levels in the control group compared to the nocebo group. Neither neuroticism F(3, 17) = 0.37, p = .77, nor impulsivity, F(3, 17) = 2.11, p = .14, were significant in moderating the relationship between nocebo suggestions and food cravings. However, impulsivity independently showed a significant negative effect on craving ratings, where higher impulsivity was related to lower food cravings, b = -11.07, t(df) = -2.18, p = .04. The study’s limitations included a small sample size and ambiguous definitions of nocebo effects, which could have affected the results. Future research should focus on exploring other personality traits to deepen our understanding of their effect on nocebo suggestions and food cravings.Show less
Acute pain has the essential function of protecting organisms from harmful influences through painful signals that trigger protective behavioral responses. Chronic pain, however, has merely stress...Show moreAcute pain has the essential function of protecting organisms from harmful influences through painful signals that trigger protective behavioral responses. Chronic pain, however, has merely stress-inducing and disabling characteristics. To enable the development of treatment, understanding the mechanisms underlying pain experience is indispensable. Previous research has demonstrated how expectancy-induced nocebo effects (i.e., the worsening of a symptom caused by negative expectations) can provoke hyperalgesia, an increased sensitivity towards pain. The present study aimed to reproduce these findings and investigate the precise role of expectancies in the relationship between nocebo-inducing cues and the resulting pain experience. Within the context of expectancy, this study was further exploring the degree of awareness involved in the participants’ perception of their accuracy in predicting upcoming pain intensities. Sixty-nine healthy volunteers were divided between the experimental and the control condition, both of which received repeated electrical pain stimulation. Through verbal suggestion and conditioning, the experimental group learned to associate a specific color with high pain intensity and a second color with a medium intensity stimulus. In the control group, there were no instructions and the order of pain intensities and color cues was randomized. During the test phase, all color cues were accompanied by medium intensity pain to measure the magnitude of nocebo responses associated with the conditioned color as opposed to the control color. Pain expectancy and experience, as well as the extent to which they both matched, were measured through self-report scales after each stimulus-color pair. Nocebo conditioning produced the expected higher pain and expectancy ratings for the conditioned cue, as compared to the unconditioned cue in the nocebo group’s test data. Next, expectancies appeared to significantly mediate the effect of the nocebo-induction on pain experience in the experimental group. Finally, there was no significant indication that participants were aware of their degree of prediction accuracy. These findings confirm the significant involvement of expectation in pain experience and warrant further research on awareness in pain perception. Additional research is needed to provide deeper insight on the psychological processes underlying pain experience, as it will help optimize treatments for patients suffering from chronic pain.Show less
Chronic pain is one of the most prominent medical conditions associated with significant limitations in various life aspects. Nocebo hyperalgesia which refers to increased pain perception due to...Show moreChronic pain is one of the most prominent medical conditions associated with significant limitations in various life aspects. Nocebo hyperalgesia which refers to increased pain perception due to negative expectations about pain plays crucial role in pain chronification. Nocebo effects have also been linked to dispositional characteristics. Studies investigating the role of fear of pain and nocebo hyperalgesia found inconsistent results. This study used conditioning and verbal suggestions hypothesizing that nocebo hyperalgesia will occur. We further investigated the association between fear of pain and nocebo hyperalgesia, expecting a positive relationship. In this study, 27 healthy individuals were randomly assigned to either a control group or a nocebo group in which negative expectancies about pain were induced. This was done by means of conditioning, through pairing electrically painful stimuli with color cues, and by giving negative verbal suggestions about an increase in pain related to a color cue and a sham electrode. Pain levels were rated on Numerical Rating Scale (NRS) and compared between groups. Dispositional fear of pain levels was measured using the fear of minor pain subscale of the Fear of Pain Questionnaire-III (FPQ-III). Nocebo hyperalgesia was successfully induced, as reflected by a significant difference (p =.005) in nocebo responding between the two groups. No significant relationship was found between FPQ-III scores and nocebo hyperalgesia. Findings are in line with previous research suggesting that conditioning and verbal suggestions can induce nocebo hyperalgesia. Since no association has been found between fear of pain and nocebo hyperalgesia, future research should investigate this relationship using other subscales of the FPQ-III.Show less
