Przemysław Bąbel

The effect of the sex of a model on nocebo hyperalgesia induced by social observational learning

&NA; Nocebo hyperalgesia was induced by social observational learning. Its magnitude was greater after a male rather than a female model was observed. &NA; Research shows that placebo analgesia can be induced through social observational learning. Our aim was to replicate and extend this result by studying the effect of the sex of both the model and the subject on the magnitude of placebo analgesia induced by social observational learning. Four experimental (1 through 4) and 2 control (5 and 6) groups were observed: groups 1, 3, and 5 were female; groups 2, 4, and 6 were male. All subjects received pain stimuli of the same intensity preceded by green and red lights. Before receiving pain stimuli, groups 1 and 4 observed a female model and groups 2 and 3 a male model; both models simulated responses to pain stimuli preceded by green lights as less painful than those preceded by red lights. Groups 1 through 4 also rated pain stimuli preceded by green lights as less painful. Further investigation revealed that in fact subjects in experimental groups rated red‐associated stimuli as more painful than subjects from control groups who did not observe a model before receiving the same pain stimuli, indicating that nocebo hyperalgesia rather than placebo analgesia was induced. Empathy traits predicted the magnitude of nocebo hyperalgesia. Regardless of the sex of the subject, nocebo hyperalgesia was greater after the male model was observed. The results show that social observational learning is a mechanism that produces placebo effects. They also indicate that the sex of the model plays an important role in this process.

Memory of pain and affect associated with migraine and non-migraine headaches

The main aims of this study were to assess memory of pain and pain-related affect in headache sufferers and to compare the pain memories of individuals who suffer from migraines and those who experience non-migraine headaches. A total of 313 women participated in the study, 86 of whom had a diagnosis of migraine headache. The women rated their state anxiety about having a headache, the intensity and unpleasantness of headache pain, and their emotions while actually experiencing a headache. Either three or six months later, the participants were asked to recall their state anxiety, the intensity and unpleasantness of pain, and the emotions they had felt. Regardless of the length of recall delay or migraine diagnosis, participants accurately remembered both pain intensity and unpleasantness. Together, recalled anxiety, experienced pain and recalled positive affect were the most important predictors of memories for headache, accounting for 41% and 37% of the total variance in recalled pain intensity and unpleasantness, respectively. However, participants overestimated recalled positive and negative affect. The effect of recalled affect on memory of headache, together with the overestimation of recalled affect, suggests that although memory of headache is accurate, it is influenced by distorted memories of affect.

The Effect of Question Wording in Questionnaire Surveys on Placebo Use in Clinical Practice

To identify factors that contribute to the high variability of the rates of use of placebo interventions reported in questionnaire surveys, the author investigated the effect of the explicit use of the word “placebo” in questionnaire surveys on placebo use in clinical practice on the results obtained. 190 primary care physicians in Poland were divided randomly into two groups. The groups received a questionnaire in which either the word placebo or the term “nonspecific methods of treatment” was used. The respondents who were asked explicitly about the use of placebo interventions declared that they never used placebo interventions significantly more often than participants asked about the use of nonspecific treatment methods. Moreover, the former reported significantly rarer use of placebo interventions than the latter. The study demonstrates that differences in the wording of questions in questionnaire surveys on placebo use can create statistically significant differences in results.

Classical conditioning without verbal suggestions elicits placebo analgesia and nocebo hyperalgesia.

The aim of this study was to examine the relationships among classical conditioning, expectancy, and fear in placebo analgesia and nocebo hyperalgesia. A total of 42 healthy volunteers were randomly assigned to three groups: placebo, nocebo, and control. They received 96 electrical stimuli, preceded by either orange or blue lights. A hidden conditioning procedure, in which participants were not informed about the meaning of coloured lights, was performed in the placebo and nocebo groups. Light of one colour was paired with pain stimuli of moderate intensity (control stimuli), and light of the other colour was paired with either nonpainful stimuli (in the placebo group) or painful stimuli of high intensity (in the nocebo group). In the control group, both colour lights were followed by control stimuli of moderate intensity without any conditioning procedure. Participants rated pain intensity, expectancy of pain intensity, and fear. In the testing phase, when both of the coloured lights were followed by identical moderate pain stimuli, we found a significant analgesic effect in the placebo group, and a significant hyperalgesic effect in the nocebo group. Neither expectancy nor fear ratings predicted placebo analgesia or nocebo hyperalgesia. It appears that a hidden conditioning procedure, without any explicit verbal suggestions, elicits placebo and nocebo effects, however we found no evidence that these effects are predicted by either expectancy or fear. These results suggest that classical conditioning may be a distinct mechanism for placebo and nocebo effects.

The Effect of the Type and Colour of Placebo Stimuli on Placebo Effects Induced by Observational Learning.

Research shows that placebo analgesia and nocebo hyperalgesia can be induced through observational learning. Our aim was to replicate and extend these results by studying the influence of the type and colour of stimuli used as placebos on the placebo effects induced by observational learning. Three experimental and two control groups were tested. All participants received pain stimuli of the same intensity preceded by colour lights (green and red) or geometric shapes (circles and squares). Before receiving pain stimuli, participants in the experimental groups, but not in the control groups, observed a model who rated pain stimuli that were preceded by either green lights (green placebo group), red lights (red placebo group), or circles (circle placebo group) as being less painful than those preceded by either red lights (green placebo group), green lights (red placebo group), or squares (circle placebo group). As a result participants in the experimental groups rated pain stimuli preceded by either green lights (green placebo group), red lights (red placebo group), or circles (circle placebo group) as being less painful than the participants in the control groups did, indicating that placebo effect was induced. No statistically significant differences were found in the magnitudes of the placebo effects between the three experimental groups (green placebo, red placebo, and circle placebo groups), indicating that neither the type nor the colour of placebo stimuli affected the placebo effects induced by observational learning. The placebo effects induced by observational learning were found to be unrelated to the individual differences in pain anxiety, fear of pain, and empathy.

Memory of pain induced by physical exercise

The aim of this study was to assess the memory of pain induced by running a marathon and the factors that influence it. Sixty-two marathon runners participated in the study, which comprised two phases. Immediately after a participant had reached the finishing line of the marathon, they were asked to rate the intensity and the unpleasantness of their pain and the emotions they felt at that time. Either three or six months later they were asked again to rate the intensity and the unpleasantness of the same pain experience. Regardless of the length of recall delay, participants underestimated both recalled pain intensity and unpleasantness. The pain and negative affect reported at the time of the pain experience accounted for 24% of the total variance in predicting recalled pain intensity and 22% of the total variance in predicting recalled pain unpleasantness. Positive affect at the time of pain experience was not a significant predictor of both the recalled pain intensity and pain unpleasantness. It is concluded that pain induced by physical exercise is not remembered accurately and the pain and negative affect experienced influence recall. Further research is needed on the influence of positive affect on the memory of pain.

The Effect of Positive Affect on the Memory of Pain

ABSTRACT The aim of the study was to assess the accuracy of the memory of experimentally induced pain and the affect that accompanies experimentally induced pain. Sixty‐two healthy female volunteers participated in the study. In the first phase of the study, the participants received three pain stimuli and rated pain intensity, pain unpleasantness, state anxiety, and their positive and negative affect. About a month later, in the second phase of the study, the participants were asked to rate the pain intensity, pain unpleasantness, state anxiety, and the emotions they had felt during the first phase of the study. Both recalled pain intensity and recalled pain unpleasantness were found to be underestimated. Although the positive affect that accompanied pain was remembered accurately, recalled negative affect was overestimated and recalled state anxiety was underestimated. Experienced pain, recalled state anxiety, and recalled positive affect accounted for 44% of the total variance in predicting recalled pain intensity and 61% of the total variance in predicting recalled pain unpleasantness. Together with recent research findings on the memory of other types of pain, the present study supports the idea that pain is accompanied by positive as well as negative emotions, and that positive affect influences the memory of pain.

How Classical Conditioning Shapes Placebo Analgesia: Hidden versus Open Conditioning

Objective To investigate the influence of expectancy of pain intensity, fear of pain (trait), and fear (state) on the effectiveness of hidden and open conditioning to produce placebo analgesia. Methods A total of 90 healthy female volunteers were randomly assigned to three groups (hidden conditioning, open conditioning, and control) that received electrical stimuli preceded by either orange or blue lights. One color was paired with painful stimuli (control stimuli) and the other color was paired with nonpainful stimuli (conditioned stimuli) in both the hidden and open conditioning groups. Only participants in the open conditioning group were informed about this association. In the control group, both color lights were followed by control stimuli. In the testing phase, both colored lights were followed by identical control stimuli. Participants rated pain intensity, expectancy of pain intensity, fear, and fear of pain. Results A significant analgesic effect was found only in the hidden conditioning group, where no explicit verbal suggestions were provided. Hidden conditioning had an effect on expectancy and fear-participants in the hidden conditioning group expected less pain and experienced less fear in relation to conditioned stimuli. Fear was the only predictor of placebo analgesia in the hidden conditioning group. Neither expectancy of pain intensity nor fear of pain predicted placebo analgesia. Conclusions Fear seems to be a more important factor than expectancy in producing placebo analgesia induced by hidden conditioning.

The Influence of State and Trait Anxiety on the Memory of Pain

Objective The study aimed to assess the accuracy of memories of both pain and the state anxiety that accompanies experimentally induced pain and to investigate the factors that influence the memory of experimental pain. Methods Forty-nine healthy female volunteers participated in the study. The participants received three electrocutaneous pain stimuli during the first phase of the study and rated the pain intensity, pain unpleasantness, and state anxiety they felt at that moment. Trait pain anxiety was measured by the Pain Anxiety Symptoms Scale and the Fear of Pain Questionnaire. During the second phase of the study, three or six months later (depending on the experimental group), the participants were asked to rate the pain intensity, pain unpleasantness, and state anxiety they had felt during the first phase of the study. Results Recalled pain intensity and unpleasantness and the state anxiety that accompanied the pain experience were remembered accurately, regardless of the recall delay. Both recalled pain intensity and unpleasantness were predicted by experienced pain, experienced and recalled state anxiety, and trait pain anxiety, that is, scores for physiological anxiety, cognitive anxiety, escape/avoidance, and severe pain. Conclusions The present study demonstrates that a specific type of trait anxiety (pain anxiety) influences the memory of pain. The study is not only the first to investigate the influence of trait anxiety on the memory of experimental pain, it also is the first study to determine the effect of a specific form of anxiety (pain anxiety) on the memory of experimentally induced pain.

Nabywanie reakcji emocjonalnych: rekonstrukcja i rewizja eksperymentu z udziałem Małego Alberta

In 1920 John B. Watson and Rosalie Rayner published the results of the study experiment describing how they had conditioned an 11-month-old boy (known as Little Albert) to fear a rat. The experiment is one of the best known and the most frequently cited empirical studies in the history of psychology. Many studies and theories suggesting the role of learning processes in the development of emotional responses were initiated by the Little Albert experiment. The article summarizes the procedures and results of the experiment reported by J.B. Watson and R. Rayner. The importance and impact of the results of the experiment on the development of psychological theories and research is discussed. Errors in the discussions of the Little Albert experiment in Polish psychological literature are identifi ed. The results of the latest historical research on the Little Albert experiment are summarized and their consequences are discussed