ABSTRACTS

Introduction to the Special Series: Experimental Pain as a Model for the Study of Clinical Pain

Karen M. Gil, Duke University Medical Center

Experimental pain methods have been used historically to examine sensory and perceptual mechanisms of pain report and response, generally in healthy populations. However, recent research points to the utility of these methods to investigate a variety of questions related to clinical pain. In this paper, experimental pain induction and measurement are briefly overviewed to provide readers with some background in these techniques. The utility of experimental pain induction techniques are overviewed with respect to three important emerging areas of clinical pain research: a) extending our understanding of the mechanisms of pain report and response, b) assessment and prediction of pain report and response, and c) the use of experimental pain as a vehicle to train pain coping skills and to evaluate their effectiveness in cognitive behavioral treatment. In addition, the unique contribution of each empirical paper in this special series is highlighted with respect to these three emerging areas.



The Influence of Different Standards on the Evaluation of Pain: Implications for Assessment and Treatment

Jennifer J. Wilson, William F. Chaplin, and Beverly E. Thorn, University of Alabama

Pain is a personal event, yet much research concerns how people compare their pain to the pain of others. In this study, we assessed the relative impact of positive and negative versions of normative, ipsative, and imaginary standards on the experience of pain under laboratory conditions. We expected that self-referent standards (ipsative, imaginary) would have more influence than other-referent standards (normative) on the evaluation of pain. The effect of manipulating these standards on changes in subjects' tolerance times and pain intensity ratings from Trial 1 to Trial 2 was evaluated. The normative and ipsative standards significantly affected pain intensity ratings and the ipsative standard significantly affected tolerance times. These results do not support our intuitions about the relative importance of self-referent standards over other-referent standards in evaluating the experience of pain. The assessment and treatment implications of the enigmatic influence of normative information on pain is discussed.



Perceptual Differences Between Patients With Chronic Low Back Pain and Healthy Volunteers Using Magnitude Matching and Clinically Relevant Stimuli

Adam K. Fuller and Michael E. Robinson, University of Florida

Perceptual differences between patients with chronic pain and control subjects have been shown for experimental pain stimuli as well as nonpainful stimuli. The present study investigated the perceptual differences between patients with chronic pain and control subjects using clinically relevant stimuli requiring pain and nonpain related judgments. Magnitude matching was used to compare 16 patients with chronic low back pain (CLBP) with 16 control subjects in their perception of pain and heaviness during exercise on a lumbar exercise apparatus. The patients with CLBP discriminated levels of clinically relevant stimuli better than normals based on pain ratings, but were equal in discriminability when making heaviness ratings. The patients with CLBP also underestimated the heaviness of weights lifted with their lower backs, which may represent a generalization of an under-reporting style to relevant but nonpainful judgments.



A Psychophysiological Analysis of Spouse Solicitousness Towards Pain Behaviors, Spouse Interaction, and Pain Perception

Herta Flor, Humboldt University, Caterina Breitenstein, University of Tubingen, Niels Birbaumer, University of Tubingen and University of Padova, and Michael Furst, University of Tubingen

The purpose of this study was to determine the relationship of marital interaction and spouse solicitousness to the perception of acute pain stimuli and psychophysiological reactivity. Seventeen chronic back pain patients and fifteen matched healthy controls and their significant others participated in two cold pressor tests (one in the presence, one in the absence of the spouse) and both a neutral and conflictual verbal interaction. Higher levels of solicitousness of the spouses were related to higher pain perception in the spouse present condition for the patients only. Lumbar muscular reactivity was generally elevated for the patients during the conflictual interaction. The interaction of the patients' spouses was characterized by more acceptance and agreement than that of the healthy controls' spouses; patients with highly solicitous spouses showed less direct expression than those with low solicitous spouses. These data suggest that spouse solicitousness is associated with heightened pain perception in chronic pain patients, muscular reactivity seems to be related to patient status only.



Experimental Pain Sensitivity and Reports of Negative Thoughts in Adults With Sickle Cell Disease

Karen M. Gil, George Phillips, Deborah A. Webster, Nancy J. Martin, Mary Abrams, and Merida Grant, Duke University Medical Center, W. Crawford Clark and Malvin N. Janal, Columbia University

Studies have found that reports of negative thoughts are significant predictors of pain report, health care use, and psychosocial adjustment in adults with sickle cell disease (SCD); however, the mechanisms of the relationship are not clear. In this study, 58 adults with SCD completed an experimental pain induction task (finger pressure). Sensory decision analyses determined sensory discrimination (the ability to discriminate lower and higher intensities) and response bias (the tendency to readily report pain during noxious stimulation). Hierarchical regression analyses controlling for subject gender and acute disease status indicated that individuals who reported more negative thoughts had a greater tendency to report pain during noxious stimulation even to stimuli of relatively low intensity. Reports of negative thoughts were unrelated to sensory discrimination, suggesting that motivational and attitudinal factors, rather than sensory factors, were involved. Clinical implications for health care providers who treat patients with severe SCD pain are discussed.



Neural Networks for Behavior Therapists: What They Are and Why They Are Important

Warren W. Tryon, Fordham University

Behavior therapy is predicated upon learning; many normal and abnormal behaviors are thought to be learned. Neural networks are presented as a general biologically inspired approach to learning that is as relevant to human as to animal behavior. They provide plausible proximal mechanisms for implementing the psychological processes of perception, cognition, memory and language that mediate behavior. They provide plausible proximal causal mechanisms for retaining the results of operant conditioning and behavioral selection. In sum, the present article provides a basis for theoretical unification within behavior therapy specifically and psychology generally.



PTSD and Major Depression: Methodological and Treatment Considerations in a Single Case Design

Pallavi Nishith, Diana E. Hearst, Kim T. Mueser, and Edna B. Foa, Medical College of Pennsylvania, Eastern Pennsylvania Psychiatric Institute

A case of successful cognitive behavioral treatment of a woman diagnosed with assault-related posttraumatic stress disorder PTSD) and comorbid major depression is presented. The client was treated using a combination of stress inoculation, cognitive restructuring, and imaginal in vivo exposure. A statistical technique based on classical test theory (Yarnold, 1988) was used to evaluate the client's progress in treatment. After 18 sessions, few statistically significant improvements were noted, although visual inspection of the data suggested improvements. However, after an additional six sessions devoted solely to exposure-based treatment, dramatic improvements were observed, which were maintained at one- and three-month followups. The case highlights the utility of statistical analysis in single case designs to evaluate the clinical decisions made in the selection of target behaviors for treatment of PTSD when comorbid disorders are present.



Does Distraction Interfere With Fear Reduction During Exposure? A Test Among Animal-Fearful Subjects

Beverly I. Rodriguez and Michelle G. Craske, University of California, Los Angeles

Theoretical conceptualizations of distraction as an inhibitor of fear reduction during exposure were tested among 60 subjects with marked animal fears. Subjects underwent high or low intensity in vivo exposure in the presence of highly affective slides (high distraction), neutral slides (low distraction), or no slides. Self-reported attention did not differ between the high and low distraction groups; thus, data from these groups were combined in the analyses. The combination of distraction and high exposure intensity was found to interfere both with self-reported fear reduction during exposure and with the pre- to post-exposure behavioral approach tasks; improvement in pre- to post-exposure behavioral approach was impeded also. Distraction had no impact under low intensity exposure conditions. Counter to prediction, return of fear was not evident across groups. Heart rate increased in all groups during exposure, suggesting a possible sensitization effect. Theoretical and clinical implications are discussed, and recommendations for future research are provided.



Influence of Loud Behavioral Consequences on Attention Deficit Hyperactivity Disorder

Martha J. Meyer and Sydney S. Zentall, Purdue University

Students with attention deficit hyperactivity disorder (ADHD), with aggression (H/A) and without aggression (H), and their classmates without disability were observed during play before and after watching taped interactions between a normal peer and a child with H/A. In one of the videotapes, the peer responded loudly to the aggressive behavior and in the other to the prosocial behavior of the child with H/A. The subsequent effects of this observation were assessed in a randomized control-group pretest-posttest design with three levels of group, H, H/A, and the contrast group, CG, and two levels of a video condition, loud 80 dB and normal 65 dB peer responses, to aggressive or to prosocial behavior. Prevideo group differences in activity were observed for the combined ADHD groups versus the CG, and for the H versus the H/A subgroups in the duration and positive nature of play with neutral toys. Using prevideo data as a covariate, group by condition interactions were obtained in the solitary play setting in support of predictions. Boys with ADHD differed from the contrast group with more negative behavior, and they played less with friendly toys only after observing a loud peer response to aggression. Overall implications were that loud reactions to aggressive behavior increase aggression for mildly disordered students with ADHD, while decreasing aggression for the contrast group.



Individual Differences in Social Aggression: A Test of a Reinforcement Model of Socialization in the Natural Environment

James J. Snyder, Wichita State University, and Gerald R. Patterson, Oregon Social Learning Center

A matching law reinforcement model of individual differences in social aggression was developed and tested. Ten hours of interaction were observed in each of ten aggressive and ten nonaggressive sons with their mothers. Consistent with the matching law, the relative probability of maternal termination of conflict (negative reinforcement) contingent on sons' tactics in dyadic conflict during an earlier time period was significantly correlated with the relative probability of the sons' choice of those tactics during a later time period. Comparable matching relationships were found between maternal choice of conflict tactics and sons' negative reinforcement of their mothers' tactics. Significant between-group differences were found in the relative probability with which mothers and sons negatively reinforced each other's aggressive conflict tactics. The density of aversive social stimuli in the social environment and the functional utility of aggressive tactics in terminating conflict during earlier observations were found to be reliable predictors of between-individual and-group differences in both mothers' and sons' aggressive behavior during later interaction.