Attentional control and the competition between nonpain goals and the threat of pain.

BACKGROUND: Fully understanding attention to pain requires taking into account the motivational context. Both pain- and (nonpain) goal-related information attracts attention. An intriguing question is which attentional bias prevails when pain- and goal-related information co-occurs? Reduced attentional bias towards pain- and goal-related information was predicted when the other competing information was presented simultaneously. Moreover, trait attentional control was predicted to be associated with stronger attentional bias towards goal-related information particularly in the presence of pain-related information. METHODS: Attentional competition between pain- and (nonpain) goal-related information was measured in ninety participants using a dot-probe task presenting two stimuli (pain-related, goal-related or neutral) simultaneously. Reaction time was the dependent variable. Dot-probe trials alternated with goal trials to induce a temporary goal. Trait attentional control was measured with the attentional control scale. RESULTS: For pain-related neutral stimulus pairs, participants responded fastest when probes appeared on the same, compared to the opposite, location as the pain-related stimulus. For pain-goal-related stimulus pairs, responses were fastest when probes appeared on the same, compared to the opposite, location as the goal-related stimulus. Higher trait attentional control was associated with faster responding when probes appeared on the same, compared to the opposite, location as the goal-related stimulus. Unpredicted, this effect was irrespective of the co-occurring stimulus (neutral vs. pain-related). CONCLUSIONS: The findings suggest that the unintentional allocation of attention towards events related to a temporary (nonpain) goal prevails over attentional bias to events predicting pain. Trait attentional control predicts stronger attentional allocation towards events related to a temporary goal. SIGNIFICANCE: These findings indicate that treatment interventions facilitating goal pursuit in patients with chronic pain are beneficial in reducing attentional biases towards pain-related events.

Forgetting to remember? Prospective memory within the context of pain.

BACKGROUND: Pain interferes with cognitive functioning in several ways. Among other symptoms, pain patients often report difficulties with remembering future intentions. It remains unclear, however, whether it is the pain per se that impairs prospective remembering or other factors that often characterize people with pain (e.g. poor sleep quality). In this experiment, we investigated whether prospective memory is impaired within the context of pain, and whether this impairment is enhanced when the threat value of pain is increased. METHODS: Healthy participants engaged in an ongoing word categorization task, during which they received either experimental pain stimuli (with or without threatening instructions designed to increase the threat value of pain), or no pain stimuli (no somatic stimuli and no threatening instructions). Crucially, participants were also instructed to perform a prospective memory intention on future moments that would be signalled by specific retrieval cues. RESULTS: Threatening instructions did not differentiate the pain groups in terms of pain threat value; therefore, we only focus on the difference between pain and no pain. Pain and no-pain groups performed the prospective memory intention with similar frequency, indicating that prospective memory is not necessarily impaired when the intended action has to be performed in a painful context. CONCLUSIONS: Findings are discussed in the framework of the multiprocess theory of prospective memory, which differentiates between the spontaneous and the strategic retrieval of intentions. Methodological considerations and suggestions for future research are discussed. SIGNIFICANCE: This laboratory study combines established methods from two research fields to investigate the effects of a painful context on memory for future intentions. Painful context did not impair performance of a prospective memory intention that is assumed to be retrieved by means of spontaneous processing.

Attention allocation to ambiguous health/somatic threat cues.

BACKGROUND: An influential idea is that attentional bias to information related to pain or pain-related negative affect underlies persistent pain problems. Such information is however often ambiguous. If ambiguous input is perceived as pain or threat related, attention to this stimulus would be enhanced compared with stimuli with no (dominant) pain-/threat-related meaning. Attentional bias to ambiguous stimuli related to somatic/health threat was expected to be more pronounced with higher levels of pain catastrophizing. METHODS: University students performed a spatial cueing task including four types of word cues that were combinations of word content (somatic/health threat vs. non-threat), and word ambiguity (unambiguous vs. ambiguous), each presented for 500 or 750 ms. Attentional bias to somatic/health threat is reflected in larger cue validity effects for somatic/heath threat words than for non-threat words. RESULTS: In the 500-ms condition, cue validity effects were larger for threat than for non-threat words in participants reporting low catastrophizing, but did not depend on word content in participants reporting higher catastrophizing. In the 750-ms condition, cue validity effects did not depend on pain catastrophizing or word content. Cue validity effects did not significantly differ between unambiguous words and ambiguous homographs. CONCLUSIONS: Low catastrophizers demonstrated attentional bias to threat content. Participants reporting higher catastrophizing showed overall enhanced attentional orienting. There was no evidence for differences in (biased) attention to unambiguous and ambiguous words. Further research is needed to determine attentional bias for ambiguous pain-/threat-related stimuli in the context of consistent attentional bias for unambiguous pain-/threat-related stimuli.

Pain catastrophizing moderates the effects of pain-contingent task interruptions.

BACKGROUND: A prominent behavioural consequence of pain is the temporary suspension of current activities with intent to resume them later. Little is known about the effects of such pain-contingent task interruptions. This experiment examines the influence of pain-contingent interruptions on the amount of time spent performing a cognitive achievement task: We expected that people would spend more time on task when task performance was interrupted in response to pain (vs. no interruption), and that negative mood and pain catastrophizing would enhance this negative impact. METHODS: Healthy volunteers read behaviour descriptions until they felt they could form a good impression. Before task performance, participants underwent a negative or positive mood induction. During the task, all participants expected painful stimulation. Half of the participants in each mood induction group received an acute (electrocutaneous) pain stimulus, resulting in a 2-min break from the task. The other participants received no sensory stimulation during task performance and their performance was not interrupted. RESULTS: Results revealed no effect of mood on task performance (i.e., total number of descriptions read). There was, however, a significant interaction between task interruption and pain catastrophizing, indicating that participants with low levels of catastrophizing tended to read more descriptions when performance was interrupted than when not, whereas participants reporting relatively high levels of catastrophizing showed the reverse behavioural pattern. CONCLUSIONS: The impact of pain-contingent task interruptions was reversed in participants reporting relatively high levels of pain catastrophizing. Results are discussed with regard to interruption management in the context of chronic pain.

Does medical specialty influence the treatment of asymptomatic carotid stenosis? a Belgian multidisciplinary survey.

AIM: The aim of this study was to supplement the few data that exist regarding the potential effect of the referring medical specialty on the proposed treatment for asymptomatic carotid stenosis. METHODS: In a web survey, we presented Belgian cardiologists, neurologists and vascular surgeons with two fairly uncomplicated case vignettes on asymptomatic carotid stenosis differing only in the degree of stenosis (70-80% in case 1 and >80% in case 2). RESULTS: In both cases the suggested therapies were different per medical specialty (P<0.000002 and P<0.00002, respectively). Cardiologists were more conservative and vascular surgeons were more aggressive. Preferred therapies for both cases differed statistically significantly (odds ratio 8.63; 95% confidence interval 5.11-14.58). Suggesting a different therapy or not for case 1 and case 2 was also different per medical specialty (P<0.035). Cardiologists were most inclined to suggest a different therapy and vascular surgeons the least. Nobody switched to a more conservative treatment. Younger physicians suggested a more conservative approach (P<0.014). CONCLUSION: Different medical specialties prefer different treatments for asymptomatic carotid stenosis. Also, younger physicians seem more conservative. We elaborate on the different reasons that could explain these findings.

Body temperature and outcome after stroke thrombolysis.

AIMS: We studied whether baseline body temperature and temperature increases after stroke adversely affect outcome after thrombolysis with intravenous tissue plasminogen activator (IV tPA). METHODS: The evolution of body temperature in the first 24 h after treatment with IV tPA was described by calculating the area under the curve of the temperature over time plot relative to temperature at admission (AUCBL) and relative to a standard value of 37 degrees C (AUC37). Temperature parameters were related to functional outcome. RESULTS: The median baseline National Institutes of Health Stroke Scale of 100 consecutive patients was 16 (interquartile range 11-21) and 34 patients had a favourable response to tPA. Patients with an unfavourable outcome had a more important temperature elevation than patients who had a favourable outcome after tPA (+1 degrees C vs +0.6 degrees C, P=0.02), despite similar baseline T and had a higher AUCBL (9.79 vs 5.36, P=0.027) and more frequently showed hyperthermia relative to baseline (82% vs 56%, P=0.011). After adjustment for baseline characteristics, the presence of hyperthermia relative to baseline was associated with a reduced odds of good outcome after thrombolysis (OR 0.34, 95% CI 0.10-0.95, P=0.040). CONCLUSION: Hyperthermia relative to baseline temperature in the 24 h after intravenous thrombolysis is associated with an unfavourable outcome.

Parametric study of the peak negative acoustic pressure distribution within the image plane of a phased array transducer.

A study is presented in which the influence of pulse and transducer characteristics on the distribution of the peak negative acoustic pressure within the image plane of a phased array transducer is shown. First, the influence of the center frequency, the bandwidth of the transmitted pulse, the position of the focus point, and the properties of the phased array are investigated by computer simulation. These simulations show that both the maximal amplitude and the homogeneity of the distribution of the peak negative pressure within a sector image depend on these parameters. Most remarkably, they show that the maximal peak pressure does not necessarily occur on the geometrical symmetry axis of the array transducer but can occur at the outermost lateral lines of a sector image. Second, this effect is demonstrated experimentally by hydrophone measurements of the sound field produced by a standard, clinically used, 2.5-MHz phased array transducer. The experimental results agree well with the theoretical model. The relevance of this study for contrast echography and the safety measurements of ultrasound is discussed.

Are changes in myocardial integrated backscatter restricted to the ischemic zone in acute induced ischemia? An in vivo animal study.

Integrated backscatter (IB) from a myocardial region, calculated from radiofrequency echocardiographic data, has been proposed as a useful parameter for investigating changes in myocardial tissue induced by ischemia. In 10 closed-chest dogs, 5 minutes of myocardial ischemia was induced by either a proximal occlusion of the circumflex coronary artery (CX) (5 dogs), resulting in extensive ischemia in the posterior wall, or by occluding the distal CX vessel (5 dogs) to produce a small localized ischemic zone in the posterior wall. High-resolution digital radiofrequency data from the whole left ventricular myocardium, in the imaging plane during one complete heart cycle, were acquired with a whole-image real-time acquisition approach. Regions in the septum and posterior wall (both ischemic tissue and, in the case of distal occlusions, tissue surrounding the ischemic zone) were chosen for analysis, and IB and cyclic variation (CV) of IB were calculated. Post occlusion, an increase in mean IB values was found in the ischemic segment. However, an increase in CV was also observed in the peri-ischemic zone for the distal CX occlusion and in the septum after proximal CX occlusion. These findings show that changes in CV are not restricted to the ischemic zone but may also occur in distal myocardium. This may be explained by changes in the regional contractile state and loading conditions of the "normal" myocardium, which are altered in response to the distal ischemia.