Relevance of Religiosity for Coping Strategies and Disability in Patients with Fibromyalgia Syndrome.

Coping strategies are essential for the outcome of chronic pain. This study evaluated religiosity in a cohort of patients with fibromyalgia syndrome (FMS), its effect on pain and other symptoms, on coping and FMS-related disability. A total of 102 FMS patients were recruited who filled in questionnaires, a subgroup of 42 patients participated in a face-to-face interview, and data were evaluated by correlation and regression analyses. Few patients were traditionally religious, but the majority believed in a higher existence and described their spirituality as "transcendence conviction". The coping strategy "praying-hoping" and the ASP dimension "religious orientation" (r = 0.5, P < 0.05) showed a significant relationship independent of the grade of religiosity (P < 0.05). A high grade of belief in a higher existence was negatively associated with the choice of ignoring as coping strategy (r = - 0.4, P < 0.05). Mood and affect-related variables had the highest impact on disability (b = 0.5, P < 0.05). In this cohort, the grade of religiosity played a role in the choice of coping strategies, but had no effects on health and mood outcome.

Clustering fibromyalgia patients: A combination of psychosocial and somatic factors leads to resilient coping in a subgroup of fibromyalgia patients.

BACKGROUND: Coping strategies and their efficacy vary greatly in patients suffering from fibromyalgia syndrome (FMS). OBJECTIVE: We aimed to identify somatic and psychosocial factors that might contribute to different coping strategies and resilience levels in FMS. SUBJECTS AND METHODS: Standardized questionnaires were used to assess coping, pain, and psychological variables in a cohort of 156 FMS patients. Quantitative real-time polymerase chain reaction (qRT-PCR) determined gene expression of selected cytokines in white blood cells of 136 FMS patients and 25 healthy controls. Data of skin innervation, functional and structural sensory profiles of peripheral nociceptive nerve fibers of a previous study were included into the statistics. An exploratory factor analysis was used to define variance explaining factors, which were then included into cluster analysis. RESULTS: 54.9% of the variance was explained by four factors which we termed (1) affective load, (2) coping, (3) pain, and (4) pro-inflammatory cytokines (p < 0.05). Considering differences in the emerged factors, coping strategies, cytokine profiles, and disability levels, 118 FMS patients could be categorized into four clusters which we named "maladaptive", "adaptive", "vulnerable", and "resilient" (p < 0.05). The adaptive cluster had low scores in disability and in all symptom categories in contrast to the vulnerable cluster, which was characterized by high scores in catastrophizing and disability (p < 0.05). The resilient vs. the maladaptive cluster was characterized by better coping and a less pro-inflammatory cytokine pattern (p < 0.05). CONCLUSION: Our data suggest that problem- and emotion-focused coping strategies and an anti-inflammatory cytokine pattern are associated with reduced disability and might promote resilience. Additional personal factors such as low anxiety scores, ability of acceptance, and persistence further favor a resilient phenotype. Individualized therapy should take these factors into account.

ADORA2A genotype modulates interoceptive and exteroceptive processing in a fronto-insular network.

Facilitated processing of interoceptive and exteroceptive information in the salience network is suggested to promote the development of anxiety and anxiety disorders. Here, it was investigated whether the adenosine 2 A receptor gene (ADORA2A) 1976T/C (rs5751876) variant - previously associated with anxiety disorders and anxiety-related phenotypes as well as general attentional efficiency -was involved in the regulation of this network. In detail, fMRI recordings of 65 healthy participants (female=35) were analyzed regarding ADORA2A genotype effects on brain connectivity related to (1) interoceptive processing in terms of functional connectivity resting-state fMRI, and (2) exteroceptive processing using dynamic causal modeling in task-based fMRI. In a subsample, cardiac interoceptive accuracy was furthermore measured via the Mental Tracking Task. ADORA2A genotype was found to modulate a fronto-insular network at rest (interoceptive processing) and while performing an executive control task (exteroceptive processing). Across both modalities, the ADORA2A TT risk genotype was associated with increased connectivity between the insula and the prefrontal cortex. The strength in connectivity correlated with interoceptive accuracy. It is concluded that alterations in fronto-insular connectivity are modulated by both the adenosinergic system and interoceptive accuracy. Thus, fronto-insular connectivity in synopsis with ADORA2A genotypic information could serve as combined biomarkers for personalized treatment approaches in anxiety disorders targeting exteroceptive and interoceptive dysfunction.

Emotion regulation in heavy smokers: experiential, expressive and physiological consequences of cognitive reappraisal.

Emotion regulation dysfunctions are assumed to contribute to the development of tobacco addiction and relapses among smokers attempting to quit. To further examine this hypothesis, the present study compared heavy smokers with non-smokers (NS) in a reappraisal task. Specifically, we investigated whether non-deprived smokers (NDS) and deprived smokers (DS) differ from non-smokers in cognitive emotion regulation and whether there is an association between the outcome of emotion regulation and the cigarette craving. Sixty-five participants (23 non-smokers, 22 NDS, and 20 DS) were instructed to down-regulate emotions by reappraising negative or positive pictorial scenarios. Self-ratings of valence, arousal, and cigarette craving as well as facial electromyography and electroencephalograph activities were measured. Ratings, facial electromyography, and electroencephalograph data indicated that both NDS and DS performed comparably to nonsmokers in regulating emotional responses via reappraisal, irrespective of the valence of pictorial stimuli. Interestingly, changes in cigarette craving were positively associated with regulation of emotional arousal irrespective of emotional valence. These results suggest that heavy smokers are capable to regulate emotion via deliberate reappraisal and smokers' cigarette craving is associated with emotional arousal rather than emotional valence. This study provides preliminary support for the therapeutic use of reappraisal to replace maladaptive emotion-regulation strategies in nicotine addicts.

Gender-specific association of variants in the AKR1C1 gene with dimensional anxiety in patients with panic disorder: additional evidence for the importance of neurosteroids in anxiety?

BACKGROUND: Neurosteroids are synthesized both in brain and peripheral steroidogenic tissue from cholesterol or steroidal precursors. Neurosteroids have been shown to be implicated in neural proliferation, differentiation, and activity. Preclinical and clinical studies also suggest a modulatory role of neurosteroids in anxiety-related phenotypes. However, little is known about the contribution of genetic variants in genes relevant for the neurosteroidogenesis to anxiety disorders. METHODS: We performed an association analysis of single nucleotide polymorphisms (SNPs) in five genes related to the neurosteroidal pathway with emphasis on progesterone and allopregnanolone biosynthesis (steroid-5-alpha-reductase 1A (SRD5A1), aldo-keto reductase family 1 C1-C3 (AKR1C1-AKR1C3) and translocator protein 18 kDA (TSPO) with panic disorder (PD) and dimensional anxiety in two German PD samples (cases N = 522, controls N = 1,115). RESULTS: Case-control analysis for PD and SNPs in the five selected genes was negative in the combined sample. However, we detected a significant association of anticipatory anxiety with two intronic SNPs (rs3930965, rs41314625) located in the gene AKR1C1 surviving correction for multiple testing in PD patients. Stratification analysis for gender revealed a female-specific effect of the associations of both SNPs. CONCLUSIONS: These results suggest a modulatory effect of AKR1C1 activity on anxiety levels, most likely through changes in progesterone and allopregnanolone levels within and outside the brain. In summary, this is the first evidence for the gender-specific implication of the AKR1C1 gene in the expression of anticipatory anxiety in PD. Further analyses to unravel the functional role of the SNPs detected here and replication analyses are needed to validate our results.

Effects of ADORA2A gene variation and caffeine on prepulse inhibition: a multi-level risk model of anxiety.

The complex pathogenesis of anxiety and panic disorder in particular has been suggested to be influenced by genetic factors such as the adenosine A2A receptor gene (ADORA2A) 1976T>C polymorphism (rs5751876) as well as neuropsychological factors such as early information processing deficits. In 114 healthy individuals (males=57, females=57) controlled for anxiety sensitivity (AS), a multi-level risk model of the development of anxiety was applied: Genetic (ADORA2A 1976T>C variant) and biochemical (300 mg of caffeine citrate vs. placebo) factors were hypothesized to influence early information processing as measured by the prepulse inhibition/facilitation paradigm (stimulus onset asynchronies (SOAs) of 60, 120, 240, 480 and 2000ms between prepulses and startle stimuli). A fourfold interaction of genotype, intervention, gender, and SOAs was discerned. Stratification by SOAs revealed that at 120 ms and 240 ms SOAs in the caffeine condition, PPI was impaired in female ADORA2A 1976TT risk genotype carriers as compared to male ADORA2A 1976TT homozygotes, while no significant effects were observed in the ADORA2A 1976CC/CT non-risk genotype or placebo group. Only in high anxiety sensitive probands, a significant intervention effect was discerned with impaired prepulse facilitation (PPF) due to caffeine. The present results point to an impaired ability to selectively process very early information and to gate irrelevant sensory information, respectively, in female ADORA2A 1976TT homozygotes in response to caffeine, providing further evidence for the adenosinergic system to be involved in the pathogenesis of anxiety.

Neural responses to smoking stimuli are influenced by smokers' attitudes towards their own smoking behaviour.

An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users) whereas others are discontent (dissonant users). Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli) and stimuli associated with the terminal stage (END-smoking-stimuli) of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula) in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex) compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli) are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli) seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant smokers experience difficulties in translating their attitudes into an actual behavior change.

Affect-modulated startle: interactive influence of catechol-O-methyltransferase Val158Met genotype and childhood trauma.

The etiology of emotion-related disorders such as anxiety or affective disorders is considered to be complex with an interaction of biological and environmental factors. Particular evidence has accumulated for alterations in the dopaminergic and noradrenergic system--partly conferred by catechol-O-methyltransferase (COMT) gene variation--for the adenosinergic system as well as for early life trauma to constitute risk factors for those conditions. Applying a multi-level approach, in a sample of 95 healthy adults, we investigated effects of the functional COMT Val158Met polymorphism, caffeine as an adenosine A2A receptor antagonist (300 mg in a placebo-controlled intervention design) and childhood maltreatment (CTQ) as well as their interaction on the affect-modulated startle response as a neurobiologically founded defensive reflex potentially related to fear- and distress-related disorders. COMT val/val genotype significantly increased startle magnitude in response to unpleasant stimuli, while met/met homozygotes showed a blunted startle response to aversive pictures. Furthermore, significant gene-environment interaction of COMT Val158Met genotype with CTQ was discerned with more maltreatment being associated with higher startle potentiation in val/val subjects but not in met carriers. No main effect of or interaction effects with caffeine were observed. Results indicate a main as well as a GxE effect of the COMT Val158Met variant and childhood maltreatment on the affect-modulated startle reflex, supporting a complex pathogenetic model of the affect-modulated startle reflex as a basic neurobiological defensive reflex potentially related to anxiety and affective disorders.

An early attentional bias to BEGIN-stimuli of the smoking ritual is accompanied with mesocorticolimbic deactivations in smokers.

RATIONALE: Biased processing of drug-associated stimuli is believed to be a crucial feature of addiction. Particularly, an attentional bias seems to contribute to the disorder's maintenance. Recent studies suggest differential effects for stimuli associated with the beginning (BEGIN-smoking-stimuli) or the terminal stage of the smoking ritual (END-smoking-stimuli), with the former but not the later evoking high cue-reactivity. OBJECTIVE: The current study investigated the neuronal network underlying an attentional bias to BEGIN-smoking-stimuli and END-smoking-stimuli in smokers and tested the hypothesis that the attentional bias is greater for BEGIN-smoking-stimuli. METHODS: Sixteen non-deprived smokers and 16 non-smoking controls participated in an fMRI study. Drug pictures (BEGIN-smoking-stimuli, END-smoking-stimuli) and control pictures were overlaid with geometrical figures and presented for 300 ms. Subjects had to identify picture content (identification-task) or figure orientation (distraction-task). The distraction-task was intended to demonstrate attentional bias. RESULTS: Behavioral data revealed an attentional bias to BEGIN-smoking-stimuli but not to END-smoking-stimuli in both groups. However, only smokers showed mesocorticolimbic deactivations in the distraction-task with BEGIN-smoking-stimuli. Importantly, these deactivations were significantly stronger for BEGIN- than for END-smoking-stimuli and correlated with the attentional bias score. CONCLUSIONS: Several explanations may account for missing group differences in behavioral data. Brain data suggest smokers using regulatory strategies in response to BEGIN-smoking-stimuli to prevent the elicitation of motivational responses interfering with distraction-task performance. These strategies could be reflected in the observed deactivations and might lead to a performance level in smokers that is similar to that of non-smokers.

Modification of caffeine effects on the affect-modulated startle by neuropeptide S receptor gene variation.

RATIONALE/OBJECTIVES: Both the neuropeptide S (NPS) system and antagonism at the adenosine A2A receptor (e.g., by caffeine) were found to play a crucial role in the mediation of arousal and anxiety/panic in animal and human studies. Furthermore, a complex interaction of the neuropeptide S and the adenosinergic system has been suggested with administration of the adenosine A2A receptor antagonist caffeine downregulating NPS levels (Lage et al., 2006) and attenuating the stimulatory effects of NPS in rodents (Boeck et al., 2010). METHODS: Thus, in the present study, the impact of the functional neuropeptide S receptor (NPSR) A/T (Asn(107)Ile; rs324981) variant on affect-modulated (neutral, unpleasant, and pleasant IAPS pictures) startle response depending on the administration of 300 mg caffeine citrate was investigated in a sample of 124 (m = 58, f = 66) healthy probands using a double-blind, placebo-controlled design. RESULTS: ANOVA revealed a significant interaction between NPSR genotype, challenge condition, and picture valence. Comparing startle magnitudes upon stimulation with neutral or emotional pictures between the placebo and caffeine condition, in AA/AT non-risk genotype carriers no significant difference was discerned, while TT risk genotype carriers showed a significantly increased startle magnitude in response to neutral stimuli (p = .02) and a significantly decreased startle magnitude in response to unpleasant stimuli (p = .02) in the caffeine condition as compared to the placebo condition. CONCLUSIONS: In summary, the present findings - extending previous evidence from rodent studies - for the first time provide support for a complex, non-linear interaction of the neuropeptide S and adenosinergic systems affecting the affect-modulated startle response as an intermediate phenotype of anxiety in humans.

ADORA2A Gene variation, caffeine, and emotional processing: a multi-level interaction on startle reflex.

There is converging evidence for genetic, biochemical, and neuropsychological factors to increase the risk for anxiety and anxiety disorders. The pathogenesis of anxiety disorders is assumed to be influenced by a complex interaction of these individual risk factors on several levels, affecting intermediate phenotypes of anxiety such as the startle reflex. Thus, in the present double-blind, placebo-controlled study we attempted to paradigmatically investigate a multi-level pathogenetic model of anxiety by testing the effect of 300 mg caffeine citrate as an antagonist at the adenosine A2A receptor vs placebo on the emotion-potentiated (unpleasant, neutral, and pleasant International Affective Picture System pictures) startle reflex in 110 healthy individuals (male=56, female=54) stratified for the adenosine A2A receptor (ADORA2A) 1976T>C polymorphism (rs5751876). In addition to the expected main effect of picture category (highest startle amplitude for unpleasant, lowest for pleasant pictures) groups across all ADORA2A 1976T>C genotype and intervention (caffeine vs placebo) groups, an interaction effect of genotype, intervention, and picture category was discerned: In ADORA2A 1976TT risk genotype carriers, highest startle magnitudes were observed after caffeine administration in response to unpleasant pictures, with this effect arising particularly from the female subgroup. Our data point to a complex, multi-level, and potentially gender-specific pathogenetic model of anxiety, with genetic and biochemical factors interactively increasing the risk of maladaptive emotional processing and thereby possibly also anxiety disorders. The present findings may eventually aid in improving primary and secondary prevention by sharpening the risk profiles of anxiety-prone individuals.

Conditioned cues for smoking elicit preparatory responses in healthy smokers.

RATIONALE: Smoking cues are theorized to be conditioned stimuli (CSs) formed by repeated pairing with drug. Smoking paraphernalia can elicit subjective and physiological responses in smokers, indicative of positive affect and motivation to consume. Although these responses are probably the result of conditioning, direct evidence from human conditioning studies with physiological measures of motivational valence is rare. OBJECTIVE: The present study investigated the motivational properties of experimentally conditioned cues for smoking. METHODS: Thirty-nine smokers completed a differential conditioning protocol. Abstract pictures were used as CSs and single puffs on a cigarette as unconditioned stimulus (US). Skin conductance responses and facial electromyography of the zygomatic, corrugator, and orbicularis oris muscles were measured during conditioning. RESULTS: The conditioned cue for smoking (CS+) elicited stronger skin conductance responses and more activity of the zygomatic and orbicularis oris muscles than the CS-. CONCLUSIONS: These results support the notion that through pairing with smoking, neutral stimuli acquire the ability to elicit preparatory physiological responses, which are assumed to play an important role in the maintenance of addiction and relapse in the natural environment.

Neural responses to BEGIN- and END-stimuli of the smoking ritual in nonsmokers, nondeprived smokers, and deprived smokers.

Drug-associated stimuli (cues) have a prominent role in addiction research because they are able to provoke craving and relapses. Generally, drug cues are seen as conditioned excitatory stimuli, which elicit drug seeking and usage. However, newer data suggest differential effects for smoking stimuli depending on their stage in the smoking ritual. Specifically, stimuli associated with the terminal stage of smoke consumption (END-stimuli) may evoke reactivity opposite to the reactivity evoked by stimuli associated with the beginning of smoke consumption (BEGIN-stimuli). This fMRI study compared 20 nondeprived smokers with 20 nonsmokers to unravel the influence of smoking-related pictures displaying the beginning (BEGIN-stimuli) and termination (END-stimuli) of the smoking ritual on neural activity in the addiction network. In addition, 20 deprived smokers (12 h deprivation) were investigated to explore the effects of deprivation on the processing of these stimuli. In nondeprived smokers, BEGIN-stimuli reliably activated the addiction network (for example, the ventral striatum, orbitofrontal cortex, and anterior cingulate cortex (ACC)). In contrast, END-stimuli triggered a differential pattern of activations as well as deactivations; deactivations were found in the ventral striatum and the ACC. Deprivation had no clear effect on the responses triggered by BEGIN-stimuli, but affected the reactivity to END-stimuli. Our data clearly suggest that stimuli associated with different stages of the smoking ritual trigger differential neuronal responses. While BEGIN-stimuli generally seem to activate the addiction network, END-stimuli presumably have some inhibitory properties. This new finding might add to a more differentiated understanding of cue reactivity and addiction.

Effectiveness of education for gastric cancer patients: a controlled prospective trial comparing interactive vs. lecture-based programs.

OBJECTIVE: Although patient education may enhance knowledge, coping with illness, and quality of life among cancer patients, it is uncertain which didactic method is most effective. We compared the impact of an interactive, patient-oriented group program to a lecture-based, information-only program in gastric cancer patients. METHODS: In this prospective, controlled trial, 121 gastric cancer patients attending inpatient rehabilitation after surgical treatment received either the interactive intervention or lectures providing information. The outcomes were patients' disease-related knowledge, active coping with illness, and quality of life (QoL) at the end of their stay and 6 and 12 months thereafter. RESULTS: Both groups improved their knowledge and QoL during rehabilitation; however, knowledge was significantly higher in the interactive group compared to the lecture group. This difference was maintained at the 6- and 12-months follow-ups. In addition, the interactive group proved superior to the lecture group regarding active coping with illness and QoL at the end of rehabilitation, but not during follow-up. CONCLUSIONS: A structured, interactive patient education program proved superior to lecture-based provision of information in regards to short-term and long-term knowledge as well as short-term coping and QoL. PRACTICE IMPLICATIONS: In gastric cancer patients, interactive patient education seems preferable over lectures.

Smoking stimuli from the terminal phase of cigarette consumption may not be cues for smoking in healthy smokers.

BACKGROUND: Stimuli from the terminal phase of smoke or drug intake are paired with drug effect but have surprisingly low cue reactivity. Smoking terminal stimuli were compared to cues under conditions of different perceived smoke intake to probe whether (1) terminal stimuli are only weak cues, (2) any effect is an artifact of rigid test conditions, and (3) terminal stimuli have a unique function during the intake ritual. MATERIALS AND METHODS: Nonabstinent, healthy smokers were tested in three experiments with one-session, within-subject cue reactivity tests. Smoking terminal stimuli and cues were compared using pictures depicting events after completion (END) and before start of smoke inhalation (BEGIN). Test pictures were presented alone and in combination with no-go symbols (from no-smoking signs) or with extra cues to decrease and to increase perceived smoke availability, respectively. Measured were subjective effects and affect modulation of the startle reflex. RESULTS: END stimuli relative to BEGIN stimuli evoked less subjective craving and pleasure but more arousal. A no-go stimulus, which reduced reports of intention to smoke, reduced the reactivity to BEGIN but only marginally affected responses to END stimuli. This was confirmed with different sets of test pictures and using tests with the startle response. An extra cue did not affect reactivity to a BEGIN stimulus but increased craving and pleasure to the END stimulus, although not to the level of BEGIN stimuli alone. CONCLUSIONS: This first systematic study of terminal stimuli found their effects to be robust and have test generality. They are probably not weak cues but evoke reactivity, which may oppose reactivity of cues. They may signal poor availability of drug. Methodological, clinical, and theoretical implications were noted.

Affective pain modulation in fibromyalgia, somatoform pain disorder, back pain, and healthy controls.

Previous research suggested that patients with fibromyalgia (FM) experience a higher pain intensity (clinical pain) than do patients with musculoskeletal pain after negative emotional priming compared to positive priming. To further examine affective pain modulation in FM, we applied an experimental pain induction to compare 30 patients with FM with 30 healthy (pain-free) participants (HC), and 30 patients with back pain (BP). For another group of 30 patients with somatoform pain disorder (SF), we predicted the same pain modulation as for FM. As primes we presented positive, neutral, negative, and pain-related pictures and assessed pain intensity in response to a fixed pressure weight. Overall, picture valence modulated pain intensities (in the order of pain-related > negative pictures > neutral), but the pain intensities between neutral and positive pictures did not differ significantly. SF reported significantly higher pain intensities than did BP and HC; FM were in between, but did not differ significantly from the three other groups. There was no interaction of priming and group. Affective modulation of pain was not specifically altered in FM and SF, but SF were more sensitive to pressure pain than BP and HC.

Altered processing of pain-related information in patients with fibromyalgia.

Pressure pain thresholds (PPTs) and event-related potentials (ERPs) elicited by emotional words were analyzed in 12 patients with fibromyalgia (FM) and 12 matched healthy subjects. PPTs were assessed at the middle finger of both hands, before and after the experiment. Overall, FM patients and healthy subjects did not differ in PPT. Nevertheless, FM patients as compared with healthy controls were characterized by a significant enhancement of pain sensitivity from the beginning to the end of the experiment indicating a long lasting sensitization due to repeated stimulation. ERPs were recorded during a language decision task where subjects had to react to unpleasant pain-related and emotionally neutral words depending on syntactic or orthographic cues. An emotional category effect was observed on N400 and P300 components of the ERP, indicating that unpleasant words elicited more positive amplitudes than neutral words. A significant group effect was observed on P200 amplitudes, showing reduced amplitudes in FM patients as compared to healthy controls. Furthermore, unpleasant pain-related compared to neutral words triggered significantly enhanced late positive slow waves in healthy controls, while a comparable effect was not found in FM patients. The ERP and PPT data suggest that FM patients are characterized by an altered cognitive processing of pain-related information and by an abnormal adaptation to mechanical pain stimuli, respectively.

Electromyographic activity of the lip muscle as a measure of puffing on a cigarette.

The electromyographic activity (EMG) of the upper lip muscle (m. orbicularis oris) during sucking on a cigarette was examined as a potential new measure of smoking behaviour. This parameter was examined under conditions of actual smoking, sham smoking and sucking on a straw. We applied psychophysical procedures (methods of magnitude production), normal and paced smoking, two conventional means to confirm puffing (video recording and changes in air pressure in a cigarette holder) on different groups of smokers (heavy and light). The data revealed that lip-EMG is a valid and reliable means to quantify sucking on a cigarette in a variety of situations common to the study of smoking. It was concluded that lip-EMG may be a sensitive and selective measure of motor activity associated with smoking. The lip-EMG may also be applied together with hand activity and breathing to identify individual puffing, particularly in heavy smokers and during actual smoking. Discussed were several applications of this method to the study of smoking and other motivated behaviour such as consumption of water and palatable fluids.