Eric E. Brodie

Analgesia through the looking-glass? A randomized controlled trial investigating the effect of viewing a 'virtual' limb upon phantom limb pain, sensation and movement.

The extent to which viewing a ‘virtual’ limb, the mirror image of an intact limb, modifies the experience of a phantom limb, was investigated in 80 lower limb amputees before, during and after repeated attempts to simultaneously move both intact and phantom legs. Subjects were randomly assigned to one of two conditions, a control condition in which they only viewed the movements of their intact limb and a mirror condition in which they additionally viewed the movements of a ‘virtual’ limb. Although the mirror condition elicited a significantly greater number of phantom limb movements than the control condition, it did not attenuate phantom limb pain and sensations any more than the control condition. The potential of a ‘virtual’ limb as a treatment for phantom limb pain was discussed in terms of its ability to halt and/or reverse the cortical re‐organisation of motor and somatosensory cortex following acquired limb loss.

IS LEFT ALWAYS RIGHT ? DIRECTIONAL DEVIATIONS IN VISUAL LINE BISECTION AS A FUNCTION OF HAND AND INITIAL SCANNING DIRECTION

Directional deviations in visual line bisection were investigated using normal subjects. Significant main effects were found for hand and initial scan direction resulting from significantly greater deviations to the left by the left hand compared with the right hand and by a scan from the left compared with a scan from the right. These results suggest that the amelioration of neglect can only be inferred from the left hand deviations of neglect patients if they are significantly leftwards of the objective middle and that the degree of leftward deviation in normal subjects results from an interaction between right hemispheric activation and unilateral allocation of attention.

Improving the clinical diagnosis of personal neglect: a reformulated comb and razor test.

Beschin and Robertson (1997) devised a simple clinical test of left personal neglect, which characterises personal grooming behaviour according to the proportion of the total activity that is directed to the left side of the body. Although this test proved highly reliable, and more sensitive than prior diagnostic techniques, its formulation may yet be improved. The present paper reports a reanalysis of Beschin and Robertsons (1997) data, using additional control subjects, and a formula which characterises personal neglect as a lateral bias of behaviour rather than as a lateralised deficit. It is shown that this formula greatly enhances the tests sensitivity to the behavioural abnormalities of brain damaged patients, and it is recommended that this modification be adopted for the future diagnosis of personal neglect.

Memory for labor pain: context and quality

&NA; The accuracy of memory for labor pain context and quality was examined in 33 women who had given birth 3–4 years previously, utilizing the McGill Pain Questionnaire and unstructured recollections of childbirth events. Subjects displayed very good memory for the context of labor pain but poor memory for its quality. In order to test whether recall was influenced by semantic information a second study investigated the extent and type of knowledge which exists about the nature of labor pain amongst 33 women who had never given birth. The description of labor pain provided by nuliparous women was found to be similar in terms of category selection and descriptors to that of parous women. This suggests that women have available semantic information about labor pain which may influence their pain recall or even their assessment of a pain experience.

Remembering an everyday pain: the role of knowledge and experience in the recall of the quality of dysmenorrhoea

Abstract The ability to describe the quality of a previous pain may be thought to be better if one had experienced that particular pain because information stored in episodic and/or semantic memory is available rather than if one had not and could only guess what the pain may be like on the basis of information stored in semantic memory. However research has shown that not only is the quality of labour pain poorly recalled by women who have given birth but also it is no better described by them than by women who have never given birth at all. In order to replicate this effect for an everyday pain, the ability to recall the quantity and the quality of dysmenorrhoea was measured in two groups of women. One group regularly experienced dysmenorrhoea, the other had never experienced it. Analysis of the pain intensity scores revealed that the ‘pain’ group reported significantly less pain 2 weeks later whereas the ‘no‐pain’ group did not significantly differ in their rating over time. Analysis of the MPQ Descriptors chosen by subjects using Cohens kappa resulted in ‘fair’ recall for both groups with no significant advantage for the ‘pain’ group. These results suggest that the episodic memory system plays a limited role in facilitating the recall of the quality of an often experienced pain. However the semantic memory system allows both previous pain sufferers and pain guessers to describe the core qualities of a pain to the same extent. Further research is required to explain why remembering the quality of a pain experience is not advantaged by episodic memory and what facilitates the transfer of a pain experience into semantic event memory.

Memory for pain? A comparison of nonexperiential estimates and patients' reports of the quality and intensity of postoperative pain.

UNLABELLED Prior research has questioned the extent to which postoperative retrospective ratings of acute pain actually reflect memory of that pain. To investigate this issue, pain ratings provided by patients who had undergone vascular surgery were compared with estimates of this pain provided by 2 groups of healthy, nonpatient participants with no personal experience of the surgery. Patient participants rated postoperative pain while actually experiencing it and again 4 to 6 weeks after surgery. Nonpatient groups read either a comprehensive information leaflet describing postoperative pain after vascular surgery, or a short general information leaflet about the surgery and provided 2 estimates of the likely nature of the pain, 4 to 6 weeks apart. Compared with patients, both nonpatient groups overestimated pain severity, and nonpatients provided with the comprehensive information leaflet were less consistent in their estimates compared with the other 2 groups. However, qualitative descriptions of the pain provided by the 3 groups shared many similarities. Our findings highlight limitations of inferring pain memory accuracy by comparing ratings given while in pain with those provided retrospectively and demonstrate the need to consider the phenomenological awareness accompanying recollections of prior pain events to advance our understanding of memory for pain. PERSPECTIVE The observed similarities between pain ratings made by individuals who have experienced a particular pain and estimates made by those without personal experience question whether retrospective pain ratings can be assumed to reflect memory of that pain. The need to adopt new approaches to assess memory for pain is highlighted.

Spatial field advantages for tactile line bisection as a function of hemispheric specialisation inferred from dichotic listening

Thirty left-ear advantaged (LEA) and 30 right-ear advantaged (REA) right-handed subjects performed tactile line bisection (TLB) in left and right spatial fields, and at midline. REA subjects were found to perform significantly better in the right spatial field than in the left and LEA subjects significantly better in the left than in the right. Significant directional deviations were found only at midline with the left hand deviating to the right and the right hand to the left. These findings suggest that TLB is primarily a spatial task subserved by feedforward motor processes and that directional deviations are due to the differential scaling of egocentric space.

VISTA-Rehab: A resource for stroke rehabilitation trials

Background Stroke rehabilitation is a complex intervention. Many factors influence the interaction between the patient and the elements of the intervention. Rehabilitation interventions are aimed at altering different domains of patient outcome including body functions, activity and participation. As a consequence, randomised clinical trials in this area are difficult to design. We developed an archive of stroke rehabilitation trials (VISTA-Rehab) to act as a resource to help trialists model and design future rehabilitation studies. Methods We developed specific eligibility criteria for the entry of stroke rehabilitation trials into the archive. We established a Steering Committee to oversee projects and publications and commenced the recruitment of rehabilitation trials into this resource. Results As of August 2009, VISTA-Rehab contains data from 23 stroke rehabilitation trials (>3400 patients). Demographic data, including age [median=73, interquartile range (63,79)], gender (male=53%) and initial dependency [median baseline Barthel index score=6, interquartile range (9,19)], are available for all patients. Outcome measures include the modified Rankin Scale, Barthel Index, Rivermead Motor Assessment, Fugl-Meyer Assessment, General Health Questionnaire and Nottingham Extended Activities of Daily Living Scale. Conclusion VISTA-Rehab expands the Virtual International Stroke Trials Archive to include rehabilitation trials. Anonymised data can be used to examine questions specific to stroke rehabilitation and to generate novel hypotheses.

An experimental investigation of the role of perceived justice in acute pain.

Emerging research suggests that perceiving injustice can compound the suffering of chronic pain, while perceiving justice serves as a positive psychological resource in this context. However, little more is currently known about the function of justice beliefs, particularly in the context of acute pain. The present study undertook this investigation, using cold pressor methodology to investigate whether trusting in the fairness of the world would help someone to cope with short‐term pain.

Drawing upon representations: an empirical study of the depiction of the human face

Two findings reported in the face perception literature—the 3/4-view advantage and the functional independence of expression and identity—were investigated for the depiction of a face by artists. Six undergraduate art students drew a female face with three different expressions and from three different viewpoints. Analysis of the accuracy of depiction of the drawings by 50 independent raters revealed that both 3/4 left and 3/4 right views led to better representations of both identity and expression. However, an interaction between the artists focus of depiction (focusing on expression or identity) and accuracy of depiction suggested that an artists route to representing expression is via identity. These findings question the notion of a clear distinction between expression and identity perception and are discussed in terms of the inhibition of higher order facial representations by artists and the maintenance of unfamiliarity.