Experimental pain thresholds influenced by sex of experimenter

Thresholds for pressure pain were tested in 64 adult human subjects (age: M=22.0 yr., SD=7.5). The subjects were young adults drawn from a student population. They were divided into two groups of men and two groups of women, with 16 participants in each group. A female experimenter tested one group of men and a male experimenter tested the other group. The women were tested in a similar way by an experimenter of the same sex for one group and the opposite sex for the other group. The two experimenters were dressed in a manner that emphasised their gender roles. The men tested by a female experimenter showed a higher average pain threshold than the men tested by a male experimenter, but there was no difference in the average pain thresholds of the two groups of women.     

A comparison of pain management outcomes for disability compensation and non-compensation patients

Abstract

In this study, 50 men in an in-patient comprehensive rehabilitation program receiving disability compensation were compared with 25 non-recipients with respect to pre-and post-program measures of personality functioning. physical functioning and reported pain. On the pre-program measures. the only significant difference emerging between the two groups was found on the Mf scale of the MMPI, with the compensation group showing a slightly lower mean score. The two groups responded equally well on virtually all outcome measures. One interesting exception was found on the subjective measure of pain. which showed the compensation group reporting a higher level of subjective pain, and the non-compensation group a lower level than would be predicted on the basis of pre-program scores. Overall. and contrary to popular belief. the results suggest that compensation recipients can derive considerable benefit from pain management interventions despite the ostensible reinforcement provided by disability payments.     

Assessing self-report of pain: A comparison of two recording procedures

Intensive vs. reduced demand self-monitored pain levels were compared in nine pain patients. Each patient self-monitored pain intensity on a 6-point scale every 2 hr. Overall, daily mean and maximum pain levels were calculated for each patient (1) across all intervals (intensive self-monitoring) and (2) four times per day, at meal times and bedtime (reduced-demand self-monitoring). Differences were found to be negligible. The reduced-demand procedure produced data that were closely representative of pain fluctuations indicated in the more intensive bihourly ratings. Results are discussed in terms of the representativeness and standardization in pain self-monitoring as well as possible enhancement of recording compliance through the use of the less demanding four times per day procedure.Portions of these data were presented at the meeting of the Association for Behavior Analysis, Dearborn, June 1979.     

Effects of steady-state exercise on perceived pain: comparison of sedentary students and cyclists

In this study, the effect of fitness level on perceived pain before and after a steady state exercise was investigated. Ten trained cyclists (M age=25.2 yr., SD=4.9) and 10 sedentary men (Mage=24.5 yr., SD=2.2) performed a maximal graded test on a cycle ergometer. At least 48 hr. later the participants of both groups performed a 30-min. steady-state cycling test at 75% of VO2 max. Before the steady-state exercise and 5- and 30-min. postexercise, a pressure pain stimulation test was applied on the finger of each participant. Perceived pain was measured with Borg's CR10 scale at the end of each pain stimulation. The results indicated no significant changes in perceived pain between the pre-exercise and 5- and 30-min. postexercise values (effect sizes=.07 and .19, respectively). Moreover, no significant difference in perceived pain was found between the groups for pre-exercise (ES=.02) and 5- and 30-min. postexercise (ES=.16 and .21, respectively) values. These results do not confirm the analgesic effects usually observed after steady state exercise. Therefore, it is not possible to compare the analgesic effect of this exercise mode between participants characterized by different fitness levels.     

A comparison of race‐related pain stereotypes held by White and Black individuals

Pain judgments are the basis for pain management. The purpose of this study was to assess Black and White participants' race‐related pain stereotypes. Undergraduates (n = 551) rated the pain sensitivity and willingness to report pain for the typical Black person, White person, and themselves. Participants, regardless of race, rated the typical White person as being more pain sensitive and more willing to report pain than the typical Black person. White participants rated themselves as less sensitive and less willing to report pain than same‐race peers; however, Black participants rated themselves as more pain sensitive and more willing to report pain than same‐race peers. These findings highlight similarities and differences in racial stereotypic pain beliefs held by Black and White individuals.     

Some affective consequences of social comparison and reflection processes: the pain and pleasure of being close

A self-evaluation maintenance (SEM) model of social behavior was described. According to the comparison process, when another outperforms the self on a task high in relevance to the self, the closer the other the greater the threat to self-evaluation. According to the reflection process, when another outperforms the self on a task low in relevance to the self, the closer the other the greater the promise of augmentation to self-evaluation. Affect was assumed to reflect threats and promises to self-evaluation. In three studies, subjects were given feedback about own performance and the performance of a close (friend) and distant (stranger) other on tasks that were either low in self-relevance (Study 2) or that varied in self-relevance (Studies 1 and 3). In Study 1 (N = 31), subjects' performance on simple and complex tasks after each feedback trial served as a measure of arousal. Being outperformed by a close other resulted in greater arousal than being outperformed by a distant other. In Study 2 (N = 30), evaluative ratings of words unrelated to task performance served as an indirect measure of affect. Results indicated that when relevance is low, more positive affect is associated with a friend's outperforming the self than either a friend's performing at a level equal to the self or being outperformed by a stranger. In Study 3 (N = 31), subjects received feedback while their facial expressions were monitored. Pleasantness of expression was an interactive function of relevance of task, relative performance, and closeness of comparison other. The results of all three studies were interpreted as being generally consistent with the SEM model.     

Chest pain without coronary artery disease: An exploratory comparison with panic disorder

Recent reports have indicated similarities between patients with persistent chest pain of nonorganic origin and patients with panic disorder. In order to explore this association further, we administered a structured interview and three self-report measures (State-Trait Inventory, Beck Depression Inventory, and SCL90-R) to three subject groups: (1) a sample with persistent chest pain (CP; n=14) who had been screened and found to have normal coronary arteries, (2) a sample of patients with panic disorder (PD; n=14), and (3) a sample of matched normals (n=14). CP patients were considered to be free of coronary artery disease (CAD) following normal cardiac catheterization and/or normal thallium stress tests and were not diagnosed initially with panic disorder. PD patients were diagnosed with a standardized psychiatric interview and were free of organic causes of panic. Using an exploratory data analytic approach, the results indicated that both CP and PD samples reported increased levels of state and trait anxiety (p <.0001), depression (p <.01), and somatization (p <.0001) compared with normals. CP patients differed from PD patients in their less frequent use of anxiolytic medication (p <.01) and lower levels of reported panic anxiety and phobic avoidance (p <.0001). These data suggest that persistent chest pain in the absence of CAD shares some features with panic disorder, yet differs from panic in key ways as well. The results are discussed in light of the role of anxiety in contributing to symptom labeling.This research was supported by Grant 86G-491 from the American Heart Association, Texas Affiliate, to J.G.B. H.T. is the recipient of USPHS Research Career Development Award K04-HL-0122246.     

The role of values with personal examples in altering the functions of pain: comparison between acceptance-based and cognitive-control-based protocols

The purpose of the present study was twofold. First, to compare the effect of establishing a motivational context of values on pain tolerance, believability, and reported pain, with three experimental conditions: pain acceptance (ACT condition), pain control (CONT condition), or no values (untrained condition). Second, the study aimed to isolate the impact of adding the corresponding coping strategies to both the ACT and the CONT conditions. Thirty adults were randomly assigned to one of the three experimental conditions. The participants went through the pain task in two occasions (Test I and Test II). In Test I, the effects of the ACT-values protocol (which established pain as part of valued action), the CONT-values protocol (which established high pain as opposed to valued action), and the no-values protocol, were compared. In Test II, the effect of adding the corresponding coping strategy to each condition (defusion for ACT vs. suppression for CONT) was examined. Test I showed a clear superiority of the ACT-values protocol in increasing tolerance and lowering pain believability. In Test II, the superiority of the ACT protocol was replicated, while the CONT protocol proved useful to reduce reported pain, in accordance with previous studies.     

A comparison of coping strategies in patients with fibromyalgia,chronic neuropathic pain,and pain‐free controls

Patients suffering from chronic pain may benefit from learning adaptive coping strategies. Consensus on efficient strategies for this group of patients is, however, lacking, and previous studies have shown inconsistent results. The present study has examined coping strategies in two distinctly different groups of chronic pain patients and a group of healthy controls. Thirty neuropathic pain (NP) patients, 28 fibromyalgia (FM) patients, and 26 pain‐free healthy controls completed the Coping Strategy Questionnaire (CSQ‐48/27) and rated their daily pain. The results showed that FM and NP patients did not cope differently with pain. The only difference between the groups was that FM patients felt more in control of their pain than NP patients. Both patient groups used more maladaptive/passive coping strategies, but surprisingly also more adaptive/active coping strategies than healthy controls. However, FM patients with high levels of passive strategies felt less in control than FM patients with low levels of passive strategies. This was not seen in NP patients. An important implication for clinical practice is therefore that passive coping strategies should be restructured into active ones, especially for FM patients. Otherwise, the same psychological treatment model can be applied to both groups since they use similar coping styles.     

Relationship between anxiety and dyspnea on exertion in patients with chronic obstructive pulmonary disease

Dyspnea limits exercise in patients with chronic obstructive pulmonary disease (COPD) and is known to induce anxiety. Little is known whether anxiety contributes to exercise-induced dyspnea, which in turn might influence the outcome of diagnostic tests. The aim of the present study was to examine the relationship between general anxiety and dyspnea on exertion in patients with COPD. Ninety patients with stable COPD participated; 44 men, mean age 61 (standard deviation (SD) 10.4), and mean forced expiratory volume in 1 second (%pred.) 40.5 (SD 16.9). All participants performed pulmonary function tests and an incremental cycle ergometry. The Modified Borg Scale was used to measure the level of dyspnea on exertion. Anxiety symptoms were assessed with the Hospital Anxiety and Depression Scale. Data were analyzed using Spearman's correlations and multivariate regression. Dyspnea on exertion was correlated with general anxiety (r=.31), age (r=-.30), and exercise capacity (r=.27). Regression analysis showed that general anxiety was associated with dyspnea on exertion, adjusted for sex, age, baseline dyspnea, and exercise capacity. Consequently, it is reasoned that results of exercise training and activities in daily living may be influenced negatively by anxiety-worsened dyspnea. Attention should be given to anxiety management in patients with COPD to optimize exercise training.     

Rollercoaster asthma: when positive emotional stress interferes with dyspnea perception

The current study assessed how negative and positive stress is related to dyspnea perception. The participants were 25 young women with a medical diagnosis of severe asthma, and 15 matched controls. Stress was induced during repeated rollercoaster rides. Results showed that negative emotional stress and blood pressure peaked just before, and positive emotional stress and heart beat peaked immediately after rollercoaster rides. Dyspnea in women with asthma was higher just before than immediately after rollercoaster rides, even in women with asthma with a rollercoaster-evoked reduction in lung function. These results suggest that stressed and highly aroused individuals with chronic asthma tend to perceive dyspnea in terms of acquired, familiar associations between dyspnea and positive versus negative feeling states, favoring either underperception or overperception of dyspnea, depending on the emotional valence of a situation.     

疼痛恐惧的形成及其对疼痛知觉的影响

脑岛、杏仁核是疼痛恐惧形成的重要神经网络中心。疼痛恐惧增强了慢性疼痛患者的疼痛知觉体验, 进而加剧抑郁、焦虑情绪和功能损伤程度。脑岛、杏仁核、前额皮层和前扣带回是疼痛恐惧影响疼痛知觉的重要神经基础。通过认知方法干预疼痛恐惧可以改善患者的抑郁、焦虑情绪, 减少功能损伤。未来研究应拓展疼痛恐惧的测量工具, 采用功能磁共振成像技术进一步揭示疼痛恐惧影响慢性疼痛患者疼痛知觉的神经机制。     

Mothers' facial expressions of pain and fear and infants' pain response during immunization

The goal of the current study was to examine the relationship between mothers' spontaneous facial expressions of pain and fear immediately preceding their infants' immunizations and infants' facial expressions of pain immediately following immunizations. Infants' observations of mothers' faces prior to immunization also were examined to explore whether these observations moderated the effect of mothers' facial expressions on infant pain. The final sample included 58 mothers and their infants. Video data were used to code maternal facial expressions, infants' observations, and infants' expressions of pain. Infants who observed their mothers' faces had mothers who expressed significantly more fear pre‐needle. Furthermore, mothers' facial expressions of mild fear pre‐needle were associated with lower levels of infants' pain expression post‐needle. A regression analysis confirmed maternal facial expressions of mild fear pre‐needle as the strongest predictor of infant pain post‐needle after controlling for infants' observations of mothers' faces. Mothers' subtle facial expressions of fear may indicate a relationship history of empathic caregiving that functions to support infants' abilities to regulate distress following painful procedures. Interventions aimed at improving caregiver sensitivity to infants' emotional cues may prove beneficial to infants in pain. Future directions in research are discussed.     

Effects of pain acceptance and pain control strategies on physical impairment in individuals with chronic low back pain

Psychosocial treatments for chronic pain are effective. There is a need, however, to understand the processes involved in determining how these treatments contribute to behavior change. Control and acceptance strategies represent two potentially important processes involved in treatment, although they differ significantly in approach. Results from laboratory-based studies suggest that acceptance-oriented strategies significantly enhance pain tolerance and behavioral persistence, compared with control-oriented strategies. There is a need, however, to investigate processes of acceptance and control directly in clinical settings. The present study investigated the effects of three brief instructional sets (pain control, pain acceptance, continued practice) on demonstrated physical impairment in 74 individuals with chronic low back pain using an analogue experimental design. After controlling for baseline performance, the pain acceptance group demonstrated greater overall functioning on a set of 7 standardized physical tasks relative to the other two groups, which did not differ from one another. Further, the acceptance group exhibited a 16.3% improvement in impairment, whereas the pain control group worsened by 8.3% and the continued practice group improved by 2.5%. These results suggest that acceptance may be a key process involved in behavior change in individuals with chronic pain.     

The effects of incorrect pain expectations on acquired fear and pain responses

Previous experimental research on the effects of incorrect intensity expectations of aversive events can be criticized because intensity expectations were not manipulated independently from changes in objective intensity. The present study aims at investigating the effects of incorrect intensity expectations on the immediate and later responses to a painful stimulus, and on the acquisition of anticipatory responses, with proper experimental control. Subjects (n = 62) received 20 painful stimuli of varying intensity. In the control group intensities were correctly signalled on all trials by an analogue signal. On 3 trials the signal was too large in the overprediction condition, and too small in the underestimation condition. Underpredicted painful experiences were related to subsequent higher pain responses on the physiological level, but not on the subjective level; and to increased anticipatory responses (increased pain expectations, uncertainty, subjective fear, skin conductance responses). Skin conductance level also indicated increased fear after underpredicted experiences. Overpredicted painful experiences were related to a faster decrease in subjective fear compared to the control group, but did not influence other variables. The findings support the notion that underpredictions contribute to the acquistion of fear and disrupt habituation processes. The asymmetrical processing of the two kinds of incorrectly predicted experiences is discussed.     

Cognitive differentiation, back pain, and psychogenic pain drawings

Two groups of subjects with back pain were studied (n = 67). All subjects underwent a battery of psychological tests which included a test of psychological differentiation (the Rod-and-Frame Test), a test of psychological defenses (Meta-contrast Technique), and the Eysenck Personality Inventory. In addition, the subjects drew a pain picture and answered a questionnaire on pain-related issues. Each group of subjects was then subdivided into 4 groups depending on the judged abnormality of their pain drawings. The two main groups were compared overall and the subgroups of the two back-pain groups compared with each other. The Meta-contrast Technique results show that depression was quite common among back-pain subjects as a whole compared to a painless group of subjects. Differences were found on field-dependence; subjects with abnormal pain drawings were more field-dependent than those with "normal" pain drawings. Few other between-group statistical differences were noted between the two back-pain groups. Expected scores on hysteria were not noted among the abnormal drawing makers, neither were there differences between the groups on the items of pain duration, physical functionings, or of depression.