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Miriam Kunz,1 Stefanie F Bunk,2 Anna J Karmann,3 Karl-Jürgen Bär,4 Stefan Lautenbacher3 1Department of Medical Psychology and Sociology, University of Augsburg, Augsburg, Germany; 2Department of General Practice and Elderly Care Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; 3Physiological Psychology, Otto-Friedrich University Bamberg, Bamberg, Germany; 4Department of Psychosomatic Medicine and Psychotherapy, University Hospital, Jena, GermanyCorrespondence: Miriam KunzDepartment of Medical Psychology and Sociology, University of Augsburg, Augsburg, GermanyTel +49 821 598-3720Fax +49 821 598-5116Email Miriam.kunz@med.uni-augsburg.dePurpose: Conditioned pain modulation (CPM) is most often assessed using self-report of pain. However, self-report of pain is not always available (eg in individuals with cognitive impairment) and is susceptible to report bias. In comparison, the facial expression of pain is more reflex-like and represents one of the most sensitive and specific non-verbal signals of pain. The aim of the present study was to investigate whether the facial expression of pain is sensitive enough to capture endogenous pain inhibition as elicited during CPM paradigms.Patients and Methods: In total, 26 female participants took part in this study. Facial and verbal responses to phasic heat pain were assessed once while participants immersed their hand in a hot water bath and once without additional stimulation. Facial responses were analyzed using the Facial Action Coding System (FACS). Verbal responses were assessed using a Numerical Rating Scale (NRS).Results: Pain-relevant facial responses as well as pain ratings to phasic heat pain were significantly reduced when participants simultaneously immersed their hand in a hot water bath compared to baseline. Thus, CPM effects could be demonstrated both on subjective as well as on facial responses. Moreover, CPM-induced changes in pain-relevant facial responses and in NRS ratings were significantly correlated.Conclusion: The present study shows that facial expressions of pain are sensitive enough to capture CPM effects. Given the proven clinical usefulness of assessing CPM, the parallel assessment of verbal and facial CPM effects might be a promising approach with wider scope of applications. Further research in other demographic healthy participant and clinical cohorts is warranted.Keywords: pain, CPM, conditioned pain modulation, facial expression, FACS

Wilco P Achterberg,1 Ane Erdal,2 Bettina S Husebo,2 Miriam Kunz,3 Stefan Lautenbacher4 1Department of Public Health and Primary Care, Leiden University Medical Center, RC Leiden, 2300, the Netherlands; 2Department of Global Public Health and Primary Care, University of Bergen, Bergen, 5020, Norway; 3Department of Medical Psychology, University of Augsburg, Augsburg, 86156, Germany; 4Department of Physical Psychology, University of Bamberg, Bamberg, GermanyCorrespondence: Wilco P AchterbergDepartment of Public Health and Primary Care, Leiden University Medical Center, Hippocratespad 21, Postzone V0-P, Room V6-76, PO Box 9600, RC Leiden, 2300, the NetherlandsTel +31 71 5268412/8427; + 31 6 23668980Email w.p.achterberg@lumc.nlAbstract: In dementia, neuropathological changes alter the perception and expression of pain. For clinicians and family members, this knowledge gap leads to difficulties in recognizing and assessing chronic pain, which may consequently result in persons with dementia receiving lower levels of pain medication compared to those without cognitive impairment. Although this situation seems to have improved in recent years, considerable geographical variation persists. Over the last decade, opioid use has received global attention as a result of overuse and the risk of addiction, while the literature on older persons with dementia actually suggests undertreatment. This review stresses the importance of reliable assessment and the regular evaluation and monitoring of symptoms in persons with dementia. Based on current evidence, we concluded that chronic pain is still undertreated in dementia.Keywords: pain, dementia, assessment, analgesic treatment

Cindy Stroemel-Scheder,1 Anna Julia Karmann,1 Elisabeth Ziegler,1 Michael Heesen,2 Katrin Knippenberg-Bigge,3 Philip M Lang,4 Stefan Lautenbacher1 1Physiological Psychology, University of Bamberg, Bamberg, Germany; 2Department of Anesthesiology and Pain Therapy, Kantonsspital Baden, Baden, Switzerland; 3Center for Pain Medicine, Regiomed Klinikum Lichtenfels, Lichtenfels, Germany; 4Department of Anesthesiology and Pain Therapy, Sozialstiftung Bamberg, Bamberg, GermanyCorrespondence: Cindy Stroemel-SchederDepartment of Physiological Psychology, University of Bamberg, Markusplatz 3, Bamberg 96045, GermanyTel +49 951 863 2056Email cindy.stroemel@uni-bamberg.dePurpose: Everyday variations in night sleep in healthy pain-free subjects are at most weakly associated with pain, whereas strong alterations (eg, sleep deprivation, insomnia) lead to hyperalgesic pain changes. Since it remains unclear how substantial sleep alterations need to be in order to affect the pain system and lead to a coupling of both functions, the present study aimed at providing sufficient variance for co-variance analyses by examining a sample consisting of both healthy subjects and chronic pain patients.Methods: A sample of 20 chronic musculoskeletal pain patients and 20 healthy controls was examined. This sample was assumed to show high inter-individual variability in sleep and pain, as pain patients frequently report sleep disturbances, whereas healthy subjects were required to be pain-free and normal sleepers. Sleep of two non-consecutive nights was measured using portable polysomnography and questionnaires. Experimental pain parameters (pressure pain thresholds (PPT), temporal summation of pain (TSP), conditioned pain modulation (CPM)) and situational pain catastrophizing (SCQ) were assessed in laboratory sessions before and after sleep. Pain patients’ clinical pain was assessed via questionnaire.Results: As expected, both groups differed in several sleep parameters (reduced total sleep time and sleep efficiency, more time awake after sleep onset, lower subjective sleep quality in the patients) and in a few pain parameters (lower PPTs in the patients). In contrast, no differences were found in TSP, CPM, and SCQ. Contrary to our expectations, regression analyses indicated no prediction of overnight pain changes by sleep parameters.Conclusion: Since sleep parameters were hardly apt to predict overnight pain changes, this leaves the association of both systems mainly unproven when using between-subject variance for verification.Keywords: sleep, chronic pain, experimental pain, clinical pain

Silvia Metzger, Bogomil Poliakov, Stefan LautenbacherDepartment of Physiological Psychology, University of Bamberg, Bamberg, GermanyBackground: Anxiety has been associated with both increased and decreased pain perception. Rhudy and Meagher (2000) showed that pain sensitivity is enhanced by anxiety (anticipation of shocks), but diminished by fear (confrontation with shocks). A problem of this approach is the confounding of emotional and attentional effects: Administered shocks (fear induction) divert attention away from pain, which might account for lower pain in this condition. Moreover, heterogeneous findings in the past might be due to inter-individual differences in the proneness to react to anxiety and fear such as ones anxiety sensitivity (AS) level.Objectives: Our aim was to clarify the association between anxiety, fear and pain. We used the NPU paradigm for inducing these emotions and recording pain sensitivity at once with one stimulus to prevent interference by distraction. We assumed that anxiety and fear affect pain differently. Moreover, we hypothesized that subjects with clinically relevant (high) AS (H-AS group) show enhanced pain perception in contrast to low AS subjects (L-AS group).Method: Forty healthy subjects (female: N=20; age M=23.53 years) participated and H-AS or L-AS status was determined by clinically discriminating cut-off scores of the Anxiety Sensitivity Index-3 (ASI-III). Emotions were induced by the application of unpredictable (anxiety) and predictable (fear) electric stimuli. Pain ratings of electric stimuli were compared between the conditions. Startle reflex and anxiety ratings were recorded.Results: Results showed no general effects of anxiety and fear on pain perception. However, anxiety enhanced pain sensitivity in H-AS subjects, whereas fear did not affect pain sensitivity. In L-AS subjects no effects on pain perception were found.Conclusion: Results revealed that anxiety, not fear, enhanced pain perception but only in subjects with clinically relevant AS levels. This indicates that subclinical AS levels are sufficient to increase pain sensitivity, in uncertain situations.Keywords: anxiety sensitivity index-3, enhanced pain sensitivity, attention effects, electric stimuli

Eva Susanne Capito, Stefan Lautenbacher, Claudia Horn-Hofmann Physiological Psychology, University of Bamberg, Bamberg, Germany Background: As known from everyday experience and experimental research, alcohol modulates emotions. Particularly regarding social interaction, the effects of alcohol on the facial expression of emotion might be of relevance. However, these effects have not been systematically studied. We performed a systematic review on acute alcohol effects on social drinkers’ facial expressions of induced positive and negative emotions. Materials and methods: With a predefined algorithm, we searched three electronic databases (PubMed, PsycInfo, and Web of Science) for studies conducted on social drinkers that used acute alcohol administration, emotion induction, and standardized methods to record facial expressions. We excluded those studies that failed common quality standards, and finally selected 13 investigations for this review. Results: Overall, alcohol exerted effects on facial expressions of emotions in social drinkers. These effects were not generally disinhibiting, but varied depending on the valence of emotion and on social interaction. Being consumed within social groups, alcohol mostly influenced facial expressions of emotions in a socially desirable way, thus underscoring the view of alcohol as social lubricant. However, methodical differences regarding alcohol administration between the studies complicated comparability. Conclusion: Our review highlighted the relevance of emotional valence and social-context factors for acute alcohol effects on social drinkers’ facial expressions of emotions. Future research should investigate how these alcohol effects influence the development of problematic drinking behavior in social drinkers. Keywords: alcohol, alcohol effects, emotion, encoding, social drinking context, facial action

C Horn-Hofmann,1 D Wolf,1 S Wolff,1 M Heesen,2 K Knippenberg-Bigge,3 P M Lang,3 S Lautenbacher1 1Department of Physiological Psychology, University of Bamberg, Germany; 2Department of Anesthesiology and Pain Therapy, Kantonsspital Baden, Switzerland; 3Department of Anesthesiology and Pain Therapy, Sozialstiftung Bamberg, Bamberg, Germany Background: Empirical evidence suggests that affective responses to pain are changed in chronic pain. The investigation of startle responses to pain might contribute to clarifying whether such alterations also expand to motivational defensive reactions. We aimed at comparing startle responses to tonic heat pain with high threat (HT) or low threat (LT) in patients with chronic musculoskeletal pain and controls. As pain-related anxiety and catastrophizing are typically elevated in chronic pain, we expected to find stronger startle responses in patients specifically under experimental HT. Methods: Patients with chronic musculoskeletal, preferentially, back pain (N = 19) and matched pain-free controls (N = 19) underwent two pain-related threat conditions (high and low) in balanced order. Only, in the HT condition, 50% of the trials were announced to include a short further noxious temperature increase at the end. Startle responses to loud tones were always assessed prior to a potential temperature increase in the phase of anticipation and were recorded by surface electromyogram. Results: Surprisingly, we observed no differences in startle responses and ratings of emotional and pain responses between patients and controls despite significantly higher pain-related anxiety and catastrophizing in the patients. Overall, startle was potentiated in the HT condition, but only in participants who started with this condition. Conclusion: Our results suggest that, in general, patients with pain are not more responsive emotionally to experimental threat manipulations despite elevated pain anxiety and catastrophizing. Instead, exaggerated responses in patients might be triggered only by individual concerns relating to pain, which are not sufficiently mirrored by our threat paradigm. Keywords: musculoskeletal pain, catastrophizing, anxiety, defensive motivation, experimental pain, startle reflex, threat induction

Violeta Dimova,1–3 Jörn Lötsch,3 Kathrin Hühne,4 Andreas Winterpacht,4 Michael Heesen,5 Andreas Parthum,1,2 Peter G Weber,6 Roman Carbon,6 Norbert Griessinger,2 Reinhard Sittl,2 Stefan Lautenbacher1 1Physiological Psychology, Otto-Friedrich University Bamberg, 2Pain Center, Friedrich-Alexander University Erlangen, 3Institute of Clinical Pharmacology, Goethe University, Frankfurt am Main, 4Department of Human Genetics, Friedrich-Alexander University Erlangen, Germany; 5Department of Anaesthesia, Kantonsspital Baden, Baden, Switzerland; 6Department of Pediatric Surgery, Friedrich-Alexander University Erlangen, Germany Abstract: The genetic control of pain has been repeatedly demonstrated in human association studies. In the present study, we assessed the relative contribution of 16 single nucleotide polymorphisms in pain-related genes, such as cathechol-O-methyl transferase gene (COMT), fatty acid amino hydrolase gene (FAAH), transient receptor potential cation channel, subfamily V, member 1 gene (TRPV1), and δ-opioid receptor gene (OPRD1), for postsurgical pain chronification. Ninety preoperatively pain-free male patients were assigned to good or poor outcome groups according to their intensity or disability score assessed at 1 week, 3 months, 6 months, and 1 year after funnel chest correction. The genetic effects were compared with those of two psychological predictors, the attentional bias toward positive words (dot-probe task) and the self-reported pain vigilance (Pain Vigilance and Awareness Questionnaire [PVAQ]), which were already shown to be the best predictors for pain intensity and disability at 6 months after surgery in the same sample, respectively. Cox regression analyses revealed no significant effects of any of the genetic predictors up to the end point of survival time at 1 year after surgery. Adding the genetics to the prediction by the attentional bias to positive words for pain intensity and the PVAQ for pain disability, again no significant additional explanation could be gained by the genetic predictors. In contrast, the preoperative PVAQ score was also, in the present enlarged sample, a meaningful predictor for lasting pain disability after surgery. Effect size measures suggested some genetic variables, for example, the polymorphism rs1800587G>A in the interleukin 1 alpha gene (IL1A) and the COMT haplotype rs4646312T>C/rs165722T>C/rs6269A>G/rs4633T>C/rs4818C>G/rs4680A>G, as possible relevant modulators of long-term postsurgical pain outcome. A comparison between pathophysiologically different predictor groups appears to be helpful in identifying clinically relevant predictors of chronic pain. Keywords: genetics, COMT, OPRM1, postoperative pain, PVAQ

Oliver Dittmar,1 Corinna Baum,1,2 Raphaela Schneider,1 Stefan Lautenbacher1 1Physiological Psychology, University of Bamberg, Bamberg, 2Institute of Psychology, Technical University of Darmstadt, Darmstadt, Germany Background: Hypervigilance to pain is the automatic prioritization of pain-related compared with other stimuli. The processing of threat information is influenced by negative contexts. Therefore, we intended to explore such context effects on hypervigilance to pain-cues, taking individual differences in self-reported vigilance to pain into consideration. Methods: In all, 110 healthy subjects viewed task-irrelevant emotional facial expressions (anger, happy, neutral, and pain) overlaid in half of the trials with a fine grid. The instructed task was to indicate the presence/absence of this grid. A threatening context was established by applying electrical stimuli slightly below pain-threshold. Using scores of Pain Vigilance and Awareness Questionnaire, the sample was divided into high vs low pain vigilant subjects. Reaction times and event-related brain potentials were recorded. Results: No distinct attentional processing of pain faces (based on the event-related brain potentials) was observed as a function of high levels of self-reported vigilance to pain and contextual threat induction. High pain vigilant subjects showed generally enhanced processing of emotional and neutral faces as indicated by parameters of early (early posterior negativity) and late (late positive complex) processing stages. This enhancement was abolished when electro-stimuli were presented. Conclusion: Contextual threat does not enhance the attentional capture of pain-cues when they are presented concurrently with competing task demands. The study could, however, replicate a generally enhanced attentional processing of emotional cues in high pain vigilant subjects. This underpins that hypervigilance to pain is related to changes in emotional processing. Keywords: vigilance to pain, primary task paradigm, PVAQ, pain face, threat

Claudia Horn-Hofmann,1,2 Patricia Büscher,1 Stefan Lautenbacher,2 Jörg Wolstein1 1Pathosychology, University of Bamberg, Bamberg, Germany; 2Physiological Psychology, University of Bamberg, Bamberg, Germany Purpose: Alcohol is believed to have pain-dampening effects and is often used as self-medication by persons with pain problems; however, experimental evidence confirming this effect is scarce. We conducted a systematic review of experimental studies on the effects of nonrecurring alcohol administration on pain perception in healthy human subjects and the underlying mechanisms.Method: Three databases (PubMed, PsycINFO, and Web of Science) were searched for relevant studies using a predefined algorithm. In a next step, irrelevant articles were excluded by screening titles and abstracts. Finally, articles were checked regarding a set of methodological criteria; only publications meeting these criteria were selected for this review. A total of 14 experimental studies were identified.Results: Overall, most of the studies were able to show a pain-dampening effect of alcohol. However, many of them had methodological shortcomings (eg, lack of placebo control, insufficient blinding, or very small sample sizes). In addition, comparability is limited due to considerable variations in alcohol administration and pain measurement. More importantly, potential mechanisms of action and moderating variables have scarcely been investigated.Conclusion: Despite the frequent use of alcohol as self-medication by persons with pain problems, there are to date only a few experimental investigations of alcohol effects on pain perceptions. The results of these studies suggest that alcohol does in fact have pain-dampening effects. However, the mechanisms implicated in these effects are still unknown, and experimental research has been limited to pain-free subjects. Future research should provide more knowledge about alcohol effects on pain, especially in chronic pain patients.Keywords: pain, experimental pain, alcohol

Wilco P Achterberg,1 Marjoleine JC Pieper,2 Annelore H van Dalen-Kok,1 Margot WM de Waal,1 Bettina S Husebo,3 Stefan Lautenbacher,4 Miriam Kunz,4 Erik JA Scherder,5 Anne Corbett6 1Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, 2Department of General Practice and Elderly Care Medicine, VU University Medical Center Amsterdam, Amsterdam, The Netherlands; 3Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; 4Physiological Psychology, Otto Friedrich University Bamberg, Bamberg, Germany; 5Department of Clinical Neuropsychology, VU University Amsterdam, Amsterdam, The Netherlands; 6Wolfson Centre for Age-Related Diseases, King's College London, London, UK Abstract: There are an estimated 35 million people with dementia across the world, of whom 50% experience regular pain. Despite this, current assessment and treatment of pain in this patient group are inadequate. In addition to the discomfort and distress caused by pain, it is frequently the underlying cause of behavioral symptoms, which can lead to inappropriate treatment with antipsychotic medications. Pain also contributes to further complications in treatment and care. This review explores four key perspectives of pain management in dementia and makes recommendations for practice and research. The first perspective discussed is the considerable uncertainty within the literature on the impact of dementia neuropathology on pain perception and processing in Alzheimer's disease and other dementias, where white matter lesions and brain atrophy appear to influence the neurobiology of pain. The second perspective considers the assessment of pain in dementia. This is challenging, particularly because of the limited capacity of self-report by these individuals, which means that assessment relies in large part on observational methods. A number of tools are available but the psychometric quality and clinical utility of these are uncertain. The evidence for efficient treatment (the third perspective) with analgesics is also limited, with few statistically well-powered trials. The most promising evidence supports the use of stepped treatment approaches, and indicates the benefit of pain and behavioral interventions on both these important symptoms. The fourth perspective debates further difficulties in pain management due to the lack of sufficient training and education for health care professionals at all levels, where evidence-based guidance is urgently needed. To address the current inadequate management of pain in dementia, a comprehensive approach is needed. This would include an accurate, validated assessment tool that is sensitive to different types of pain and therapeutic effects, supported by better training and support for care staff across all settings. Keywords: pain assessment, Alzheimer's disease, cognitive impairment, behavior

Stefan Lautenbacher,1 Oliver Dittmar,1 Corinna Baum,1,2 Raphaela Schneider,1 Edmund Keogh,3 Miriam Kunz1 1Physiological Psychology, Otto-Friedrich University Bamberg, Bamberg, Germany; 2Institute of Medical Psychology, Justus-Liebig University Giessen, Giessen, Germany; 3Centre for Pain Research and Department of Psychology, University of Bath, Bath, UK Background: Pain-related stimuli are supposed to be automatically prioritized over other stimuli. This prioritization has often been tested using primary task paradigms in which pain information is irrelevant for completing the explicitly posed task. Task-irrelevant stimuli are only processed if they are very salient, and pain-related stimuli are assumed to be salient enough. Objective: We wanted to further investigate this assumption by assessing event-related brain potentials (ERPs) – a very sensitive method for studying attention and reaction times in response to pictures of people in pain and other emotional faces – using a primary task paradigm. In addition, we assumed that individuals describing themselves as vigilant to pain are especially responsive to pain cues. Methods: One hundred pain-free subjects were tested in a primary task paradigm using pictures of facial expressions of pain, anger, happiness, and neutral mood. ERPs were assessed at midline electrodes. Vigilance to pain was assessed by the pain vigilance and awareness questionnaire. Results: In contrast to previous studies (which have used pain words), effects of facial expressions of pain and other emotions on the ERPs and reaction times were surprisingly weak throughout and did not give evidence for a distinct processing of pain-related stimuli. However, hypervigilant subjects appeared to be strongly and cognitively absorbed by all emotional stimuli. Conclusion: Accordingly, it appears that pain-related stimuli are not always of outstanding salience, but that certain characteristics (eg, type of material, emotional richness) have to be present, for pain-related stimuli to be prioritized over stimuli of other emotional content. Hypervigilance to pain may generally predispose individuals to process emotional stimuli in greater depth. Keywords: hypervigilance for pain, ERP, LPC, pain face, primary task

In 21 restrained and 20 unrestrained eaters body size perception was measured sing the video distortion technique (VDT), the image making procedure (IMP) and the kinesthetic size estimating apparatus (KSEA). Body satisfaction was assessed by questionnaires (Body Shape Questionnaire, Dieting scale of the Eating Attitudes Test). Restrained eaters showed no systematic over- or underestimation of the body size but less perceptual accuracy (in VDT and KSEA). Furthermore, they were clearly more dissatisfied with their bodies than unrestrained eaters. Both findings were unrelated to each other. In both groups depressive mood or thoughts seemed to be associated with body dissatisfaction but not with body size misperception. Objective body measures (body mass index, body fat content) were not related to either body size perception or body satisfaction. The findings suggest that a perceptual uncertainty in regard to body size (either for visual or for somatosensory aspects) has already developed in restrained eaters, which may constitute a predisposition for more overt forms of body size misperception as found in eating disorder patients.

19 patients between 23 and 65 yr. of age whose chronic back pain was caused by lumbosacral disk disease and 19 healthy volunteers matched for age and sex were studied. Pain thresholds under phasic and tonic heat stimulation and thermal thresholds for warmth and cold were measured on the right hand. The patients rated any current back pain on a visual analog scale. There was a signigicant negative correlation between current back pain and the threshold for tonic pain, but there was no correlation between current back pain and experimental tonic pain or temperature sensitivity. Hence, current back pain and experimental tonic pain seem to have an additive effect on pain perception because perceptual qualities are similar. Reduced somatosensory perception of chronic back pain patients could be demonstrated for temperature sensitivity and to a lesser degree for phasic pain, but as a consequence of the 'opposing' effect of current back pain, not for tonic pain perception.