Anxiety sensitivity and its impact on pain experiences and conditions: a state of the art

This paper serves as an introduction to the special issue of Cognitive Behaviour Therapy devoted to the topic of anxiety sensitivity (AS) and its impact on pain experiences and conditions. We provide a historical overview of relevant cognitive behavioural models of chronic pain, summarize recent models incorporating the AS construct, and introduce the papers in the special issue. These papers are organized into two sets--basic laboratory-based investigations and relatively more applied studies. We attempt to highlight some of the most important findings from each of these investigations and studies, in turn. Then, we consider several important conclusions derived from the set of special issue papers and the implications of these for the practice of cognitive-behavioural interventions with pain populations. Finally, we make several suggestions for directions for future investigations in this burgeoning area of cognitive behavioural research and practice.     

Anxiety selectively disrupts visuospatial working memory

On the basis of a review of the extant literature describing emotion-cognition interactions, the authors propose 4 methodological desiderata for studying how task-irrelevant affect modulates cognition and present data from an experiment satisfying them. Consistent with accounts of the hemispheric asymmetries characterizing withdrawal-related negative affect and visuospatial working memory (WM) in prefrontal and parietal cortices, threat-induced anxiety selectively disrupted accuracy of spatial but not verbal WM performance. Furthermore, individual differences in physiological measures of anxiety statistically mediated the degree of disruption. A second experiment revealed that individuals characterized by high levels of behavioral inhibition exhibited more intense anxiety and relatively worse spatial WM performance in the absence of threat, solidifying the authors' inference that anxiety causally mediates disruption. These observations suggest a revision of extant models of how anxiety sculpts cognition and underscore the utility of the desiderata.     

Generalization decrement in human contingency learning

An association between a cue and an outcome will generalize to a similar novel cue to some extent, but not completely. Learning theorists refer to the discrepancy between responding elicited by the original cue and the novel cue as a generalization decrement. Two experiments used a contingency learning task with human participants to compare the size of a generalization decrement between configurations of cues that were altered by adding or subtracting compositional elements. The results suggest that adding elements to a configuration can produce a generalization decrement, but removing elements produces a more robust generalization decrement. Furthermore, the generalization decrement caused by adding elements was not likely to be caused by competing orienting responses. The results are used to contrast Pearce's (1987, 1994) and Wagner's (2003) models of stimulus generalization.     

The effect of feedback sign on task performance depends on self-concept discrepancies

Control theories claim that information about performance is often used by multiple goal systems. A proposition tested here was that performance information can create discrepancies in self-concept goals, directing cognitive resources away from the task goal system. To manipulate performance information, 160 undergraduates were given false positive or false negative normative feedback while working on a task that did or did not require substantial cognitive resources. Half of the participants were then given an opportunity to reaffirm their self-concepts following feedback, whereas half were not. Feedback sign positively related to performance only for those working on the cognitively intense task and not given a chance to reaffirm. Otherwise, feedback sign was negatively related to performance, albeit weakly.     

Test-retest reliability in performance of persons with hemiparesis tracking by means of compatibly displayed myoelectric feedback derived from upper limb muscles

The aim of this study was to assess whether persons with hemiparesis will yield statistically reliable test-retest tracking performance on a procedure using limb-generated, compatibly displayed, myoelectric video feedback. A convenience sample of 50 inpatients and outpatients with upper extremity involvement of at least six months were recruited. 30 had hemiparesis and had both upper extremities tested. 20 had hemiplegia and had the nonparetic upper extremity tested. Tracking skill was measured as mean tracking error. Repeated measures analysis of variance yielded statistically significant effects of main factors: Response mode, Cursor Feedback, and Session. Extremity tested was not significant. Performance with involved limb, uninvolved limb, isometric mode, and isotonic mode all yielded positive rest-retest correlations. The reliable range of tracking error obtained from subjects with hemiparesis performing a task requiring modulation of compatibly displayed myoelectric output supports the therapeutic rationale for employing compatibly displayed video feedback in the rehabilitation of motor control.     

Stability and variability may respond differently to changes in walking speed

In gait research it has often been assumed that variability and stability are negatively correlated, where increases in variability are assumed to equate with increases in instability. The purpose of this paper is to illustrate that variability does not always equate with stability. To proof this point, a method was developed to directly assess stability and variability during the application of a visual perturbation at different walking speeds. Walking variability was measured by using the average standard deviation of the knee joint angle across the gait cycle. Walking stability was measured by the recovery time of the knee joint angle trajectory from the distortion induced by a visual perturbation that was delivered at the beginning of the stance phase. Five participants were required to walk at six different velocities on a treadmill (0.67, 0.80, 0.94, 1.07, 1.21, and 1.34 m/s). The coefficients of intraclass correlations for the experiment were 83% and 80% for the calculated stability and variability, respectively. The calculated stabilities were not sensitive to changes in walking speed (p>0.98). The calculated variability however decreased with increases in walking speed (p=0.004). No significant correlation between variability and stability was observed (r=-0.002). We suggest that gait stability is independent of variability during locomotion and should thus be measured independently.     

The applicability of deadline models: Comment on Glickman,Gray, and Morales (2005)

Glickman, Gray, and Morales (this issue) propose a statistical model for measuring the unobserved latency of stimulus-controlled processes. The model accounts for both speed and accuracy and does so by assuming participants set an internal deadline. If a stimulus-controlled response is not produced by the deadline, the participant then guesses. The applicability the model is discussed in this comment. The deadline model yields specific predictions for the case in which stimulus difficulty is manipulated in a within-block manner. In this case, it is reasonable to assume that stimulus difficulty does not affect the deadline. It is shown that in common perceptual and cognitive domains, extant data do not fully meet these predictions. Hence, practitioners need be aware of the possibility and consequences of model misspecification. This research is supported by NSF grant SES - 0095919 to J. Rouder, D. Sun, and P. Speckman.     

Testing the generality of the name letter effect: name initials and everyday attitudes

The name letter effect is the tendency to evaluate alphabetical letters in one's name, especially initials, particularly favorably. Recent evidence suggests that name initials may even predict career choices. The authors investigated whether people possess favorable attitudes toward basic attitude objects beginning with name initials, both between individuals (e.g., does Judy like jam more than does Doug?) and within individuals (e.g., does Judy like jam more than honey?). Ratings of animals, foods, leisure activities (Studies 1-4) and national groups (Studies 2-4) revealed no object preference as a function of matching name initials. However, the name letter effect emerged (Studies 3-4), as did a clear preference for brand names starting with one's name initials (Study 4). Self-esteem, narcissism, and stimuli characteristics did not reliably influence these effects. Implications for extending name letter effects to basic attitude processes are discussed.