-
Objectives: Nocebo hyperalgesia is an increase in pain through the expectation of such an increase as a consequence of a sham treatment. Nocebo hyperalgesia can be induced by observation of a model demonstrating increased pain via verbal pain ratings. The aim of the present study was to investigate whether observing natural pain behavior, such as facial pain expressions , can also induce nocebo responses. Materials and Methods: Eighty female participants (age: 22.4 y±4.8) underwent a pressure-pain procedure (algometer) on both hands and rated their pain on a numerical rating scale. All participants received ointment on one of their hands, but no explanation was given for this. Before their own participation, the participants watched a video in which a woman underwent the same procedure and who either modeled increased pressure pain upon ointment application ( nocebo condition) or showed a neutral facial expression throughout (control condition). Results: A 2×2 analysis of variance with condition ( nocebo ; control) as a between-subjects factor and ointment application (with; without) as a within-subject factor revealed a main effect for ointment and a condition×ointment interaction. In the nocebo condition, pain ratings were higher with ointment than without. Discussion: For the first time, it was shown that watching a model demonstrating pain through facial expressions induced nocebo hyperalgesia . As we mostly express pain through natural pain behavior rather than through pain ratings, this paradigm extends our knowledge of observational learning about pain and may have implications for contexts in which persons watch others undergo painful procedures.
-
-
-
-
-
-
-
-
-
Nocebo effects can be acquired by verbal suggestion, but it is unknown whether they can be induced through observational learning and whether they are influenced by factors known to influence pain perception, such as pain anxiety or pain catastrophizing. Eighty-five female students (aged 22.5 ± 4.4 years) were randomly assigned to one of three conditions. Participants in the control condition (CC) received information that an ointment had no effect on pain perception. Participants in the verbal suggestion condition (VSC) received information that it increased pain sensitivity. Participants in the social observational learning condition (OLC) watched a video in which a model displayed more pain when ointment was applied. Subsequently, all participants received three pressure pain stimuli (60 seconds) on each hand. On one hand, the ointment was applied prior to the stimulation. Numerical pain ratings were collected at 20-second intervals during pain stimulation. The participants filled in questionnaires regarding pain-related attitudes (Pain Anxiety Symptoms Scale, Pain Catastrophizing Scale, and Somatosensory Amplification Scale). Participants in the OLC showed higher pain ratings with than without ointment. Pain ratings within the CC and the VSC were at the same level with and without ointment. In the VSC, the pain ratings were higher than in the CC with and without ointment. The nocebo response correlated with pain catastrophizing but not with pain anxiety or somatosensory amplification. A nocebo response to pressure pain was induced by observational learning but not by verbal suggestion. This finding highlights the importance of investigating the influence of observational learning on nocebo hyperalgesia. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
-
-
-
-
-
Individuals with bulimia nervosa (BN) or binge-eating disorder (BED) experience more frequent and intense food cravings than individuals without binge eating. However, it is currently unclear whether they also show larger food cue-induced increases in craving (i.e., food cue reactivity) than those without binge eating, as suggested by conditioning theories of binge eating. A group of individuals with BN or BED (binge-eating group, n = 27) and a group of individuals with low trait food craving scores and without binge eating (control group, n = 19) reported their current food craving before and after a food cue exposure. Although food craving intensity significantly increased in both groups, this increase was significantly stronger in the binge-eating group than in the control group. This result is in line with conditioning models of binge eating that propose that food cues are conditioned stimuli that elicit a conditioned response (e.g., food craving) and that this association is stronger in individuals with binge eating. As food craving increased in individuals with low trait food craving scores as well—although to a lesser extent—previous null results might be explained by methodological considerations such as not screening control participants for trait food craving.
-
-
Strong implicit responses to food have evolved to avoid energy depletion but contribute to overeating in today's affluent environments. The Approach–Avoidance Task (AAT) supposedly assesses implicit biases in response to food stimuli: Participants push pictures on a monitor “away” or pull them "near" with a joystick that controls a corresponding image zoom. One version of the task couples movement direction with image content-independent features, for example, pulling blue-framed images and pushing green-framed images regardless of content (‘irrelevant feature version’). However, participants might selectively attend to this feature and ignore image content and, thus, such a task setup might underestimate existing biases. The present study tested this attention account by comparing two irrelevant feature versions of the task with either a more peripheral (image frame color: green vs. blue) or central (small circle vs. cross overlaid over the image content) image feature as response instruction to a ‘relevant feature version’, in which participants responded to the image content, thus making it impossible to ignore that content. Images of chocolate-containing foods and of objects were used, and several trait and state measures were acquired to validate the obtained biases. Results revealed a robust approach bias towards food only in the relevant feature condition. Interestingly, a positive correlation with state chocolate craving during the task was found when all three conditions were combined, indicative of criterion validity of all three versions. However, no correlations were found with trait chocolate craving. Results provide a strong case for the relevant feature version of the AAT for bias measurement. They also point to several methodological avenues for future research around selective attention in the irrelevant versions and task validity regarding trait vs. state variables.
-
A distorted body image and pronounced body dissatisfaction are hallmarks of anorexia nervosa (AN) that typically result in dietary restraint and compensatory behaviours. Cognitive biases such as negative interpretation bias are considered key maintaining factors of these maladaptive cognitions and behaviours. However, little attention has been paid to empirical tests whether negative interpretation bias exists in AN and to what degree it is associated with symptom severity. Participants in the present study were 40 women with AN and 40 healthy women with no history of an eating disorder. Body-related negative interpretation bias (i.e., a tendency to interpret ambiguous information about the own body in a negative way) was measured by a Scrambled Sentences Task. Patients with AN showed a stronger body-related negative interpretation bias than healthy controls. Within both groups, negative interpretation bias correlated strongly and positively with AN symptom severity and these effects were not moderated by levels of depressive symptoms. The findings support the idea that biased interpretation of body-related information is associated with the specific psychopathology of AN. Targeted, computerised interventions (e.g. interpretation bias modification) may help to alter these dysfunctional cognitive schemas that lie at the heart of AN.
-
Background: Heightened sensitivity towards reward and insensitivity towards disadvantageous consequences may constitute a driving factor underlying unrestricted food intake and consequent weight gain in people with overweight and obesity. Therefore, the present study applied a behavioral economics approach to investigate the potential contribution of poor reward-related decision making to unsuccessful long-term weight loss maintenance (i.e. weight cycling). Based on previous research, it was expected that successful long-term weight loss maintainers would show a better performance in a gambling task than their less successful counterparts. Methods: Reward-related decision making was assessed post hoc using the Game of Dice Task in a total of 33 overweight and obese women who had either (a) successfully maintained initial weight loss of at least 10% of their body weight over one year or (b) had regained weight until at least their initial body weight prior to weight reduction (i.e. showed weight cycling). Results: The groups did not differ in terms of age, current body weight, magnitude of initial weight reduction, educational level, and global intelligence level. As hypothesized, however, the group of successful long-term weight loss maintainers performed significantly better (i.e. showed less impulsive, more advantageous choices) in the Game of Dice Task than their less successful counterparts. Conclusions: The findings suggest that poor reward-related decision making is associated with weight cycling which is considered a key concern in weight loss treatments for overweight and obesity. Furthermore, the findings speak in favor of specific psychological interventions that are designed to bolster reward-related decision making. (PsycINFO Database Record (c) 2017 APA, all rights reserved)
-
