The relationship between frontalis muscle activity and self-reports of headache pain

The relationship between levels of frontalis muscle activity and self-reports of pain was evaluated in two studies. In Study I frontalis muscle activity and self-reports of pain collected during biofeedback treatment of muscular contraction headache clients were correlated. In Study II frontalis EMG activity was increased and decreased using biofeedback techniques while concurrent reports of headache pain were recorded. The results of Study I indicated a significant relationship between EMG activity and reported headache pain for only two of the five subjects studied. The biofeedback procedures in Study II were associated with reliable increases and decreases in EMG activity. Concordance between EMG and pain reports occurred only during the EMG increase condition. Overall correlations were significant for one of the 2 subjects. The results suggest that EMG activity may not be sufficient to account for pain reports in all chronic headache clients, and variables other than EMG activity may be influencing reports of pain in some patients.     

MODIFICATION OF COMBINED MIGRAINE-MUSCLE CONTRACTION HEADACHES USING BVP AND EMG FEEDBACK

The effect of blood volume pulse (BVP) and frontalis muscle action potential (EMG) feedback on control of vasoconstriction of the temporal artery and frontalis muscle activity in combined migraine-muscle tension subjects was investigated in a multiple baseline design (across subjects and responses). The data indicated: (a) both subjects obtained an ability to control BVP during BVP feedback and EMG during EMG feedback; (b) there were decreases in frequency of migraine headaches during BVP feedback and decreases in muscle contraction headaches during EMG feedback. The results of this study supported the theoretical explanation of two pain mechanisms involved in combined muscle contraction-migraine headaches as well as the effectiveness of biofeedback procedures that target directly the specific pain mechanism in the elimination of the two types of head pain.     

Physiological changes after biofeedback and relaxation training for multiple-pain tension-headache patients

This paper is concerned with the psychophysiology of "muscle-contraction" headaches in a group of Compensation patients suffering from multiple pain problems in addition to headaches. A total of 55 of these patients were divided into 4 groups which received frontalis EMG biofeedback, relaxation training, combined biofeedback-relaxation training, or no treatment. Differences were observed among the 3 experimental treatments and the control group with respect to headache changes, but there were no differences among groups with respect to the changes observed in four underlying physiological responses as a function of time or practice. While the subjects who showed the largest changes in headache characteristics were those who exhibited the largest decreases in frontalis EMG, these were also the subjects whose initial frontalis EMG levels were the highest. It is concluded that, in keeping with a growing literature, the link between frontalis EMG and "muscle-contraction" headaches is a tenuous one and that the changes brought about in headache symptomatology through biofeedback or relaxation training are most likely attributable to a generalization of feelings of mastery over the environment or of self-efficacy brought about in the subjects through apparent success at the task.     

Electromyographic and vasomotor activity in tension, migraine, and combined headache patients: The influence of postural variation

Electromyographic (EMG) and temporal artery vasomotor activity was evaluated in three groups of headache patients (tension, migraine and combined) and nonheadache control subjects while in reclining, sitting and standing positions. Analysis of the EMG data revealed that at all measurement sites (bilateral frontalis, bilateral trapezius) the three headache groups demonstrated significantly higher levels than the nonheadache group but did not differ from each other. A secondary analysis of the trapezius EMG data revealed that a large percentage of headache patients had “normal” EMG levels in the reclining position but showed abnormalities in the sitting and standing positions. Analysis of the left temporal artery vasomotor activity revealed that all three headache groups vasoconstricted to a significantly greater extent than the nonheadache group in the sitting and standing positions. However, a diagnosis by position interaction was found for the right temporal artery with the migraine group demonstrating a unique pattern of activity.     

Electromyographic Analysis of Responses to Third Person Intergroup Threat

This study attempts to replicate and extend the findings from Davis and Stephan’s (2011) article investigating facial electromyographic (EMG) responses to individually directed or group-directed realistic threat. Using news footage from the Columbine school shootings as a third-person threatening stimulus, participants were instructed to view the clips while considering how they felt during the original events (individually primed) or how students felt during the original events (group-primed). EMG analysis of activity levels of the medial frontalis and the corrugator supercilii indicated differential activation based on the instructions. Individually primed participants experienced more fontalis activity and group-primed participants experienced more corrugator supercilii activity. These findings replicated the Davis and Stephan results and extended it to a third person-based intergroup threat.     

Task performance and electromyopotential as functions of task difficulty and EMG feedback

The dearth of empirical research in the application of biofeedback is discussed. Exp. 1 assessed relationships among biofeedback EMG training, EMG levels, cognitive task performance, and task difficulty. 72 subjects (male or female college students) were administered 1 trial on an iconic memory task with either EMG audio feedback, sham EMG audio feedback, or no feedback. Three levels of task difficulty were used. One 20-min. training session significantly lowered EMG responses, and task performance was inversely related to task difficulty. No relationship between EMG level and task performance was observed. Exp. 2 investigated the effect of increased EMG responses on cognitive task performance for one level of difficulty. One biofeedback training session did not significantly increase frontalis EMG, and there was no relationship between increased EMG and task performance.     

Facial EMG reactions to facial expressions: A case of facial emotional contagion?

The purpose of this study is to explore whether subjects exposed to stimuli of facial expressions respond with facial electromyographic (EMG) reactions consistent with the hypothesis that facial expressions are contagious. This study further examines whether males and females differ in facial EMG intensity. Two experiments demonstrated that subjects responded with facial EMG activity over the corrugator supercilii, the zygomatic major , the lateral frontalis , the depressor supercilii , and the levator labii muscle regions to stimuli of sad, angry, fearful, surprised, disgusted and happy faces, that, to large extent, were consistent with the hypothesis that facial expressions are contagious. Aspects of gender differences reported in earlier studies were found, indicating a tendency for females to respond with more pronounced facial EMG intensity.     

Sex differences in the relationship of recall to subvocal speech in preschool children

Previous research findings indicating that preschool-age boys use verbal means to encode pictorial material whereas preschool-age girls do not were further investigated. Detailed examinations were made of the polygraph tracings and serial position curves of recall of younger (mean age = 50 months) and older (mean age = 66 months) boys and girls. The older boys were different than the other sex by age groups in that (1) their recall and subvocal speech scores were significantly correlated; (2) they engaged in greater amounts of raw EMG activity on both high-labial and low-labial trials; and (3) they recalled only a small per cent of the names of pictures they did not subvocalize. Analysis of the serial position curves of recall revealed a greater recency effect for older boys and a greater primary effect for older girls. These data strongly support the notion that girls as young as 5 and 6 years of age are using other than verbal means to encode information, whereas boys similar in age are highly reliant upon verbal encoding methods.     

Using State-Space Model with Regime Switching to Represent the Dynamics of Facial Electromyography (EMG) Data

Facial electromyography (EMG) is a useful physiological measure for detecting subtle affective changes in real time. A time series of EMG data contains bursts of electrical activity that increase in magnitude when the pertinent facial muscles are activated. Whereas previous methods for detecting EMG activation are often based on deterministic or externally imposed thresholds, we used regime-switching models to probabilistically classify each individual’s time series into latent “regimes” characterized by similar error variance and dynamic patterns. We also allowed the association between EMG signals and self-reported affect ratings to vary between regimes and found that the relationship between these two markers did in fact vary over time. The potential utility of using regime-switching models to detect activation patterns in EMG data and to summarize the temporal characteristics of EMG activities is discussed.     

The face of schadenfreude: Differentiation of joy and schadenfreude by electromyography

The present study investigated whether the facial expression of the social emotion schadenfreude, the pleasant emotion which arises in response to another’s misfortune, can be differentiated from the facial expression of joy. Schadenfreude was induced by videos displaying unsuccessful penalty shots of Dutch soccer players and joy by successful penalty shots of German soccer players. Thirty-two participants watched videos while the activity of four facial muscles was recorded electromyographically. Furthermore, they judged each stimulus according to valence, arousal, joy, schadenfreude and sadness. Electromyography (EMG) results revealed that schadenfreude expressions did not differ from joy with regard to involved muscles (increase of Musculus zygomaticus major and M. orbicularis oculi activity, decrease of M. corrugator supercilii activity, no activity change of M. frontalis medialis). Furthermore, facial reactions developed fast in both conditions and EMG indicated stronger reactions in the schadenfreude condition, but according to ratings participants felt more pleasure in the joy condition.     

Reorganised anticipatory postural adjustments due to experimental lower extremity muscle pain

Automated movements adjusting postural control may be hampered during musculoskeletal pain leaving a risk of incomplete control of balance. This study investigated the effect of experimental muscle pain on anticipatory postural adjustments by reaction task movements. While standing, nine healthy males performed two reaction time tasks (shoulder flexion of dominant side and bilateral heel lift) before, during and after experimental muscle pain. On two different days experimental pain was induced in the m. vastus medialis (VM) or the m. tibialis anterior (TA) of the dominant side by injections of hypertonic saline (1 ml, 5.8%). Isotonic saline (1 ml, 0.9%) was used as control injection. Electromyography (EMG) was recorded from 13 muscles. EMG onset, EMG amplitude, and kinematic parameters (shoulder and ankle joint) were extracted. During shoulder flexion and VM pain the onset of the ipsilateral biceps femoris was significantly faster than baseline and post injection sessions. During heels lift in the VM and TA pain conditions the onset of the contralateral TA was significantly faster than baseline and post injection sessions in bilateral side. VM pain significantly reduced m. quadriceps femoris activity and TA pain significantly reduced ipsilateral VM activity and TA activity during bilateral heel lift. The EMG reaction time was delayed in bilateral soleus muscles during heels lift with VM and TA pain. The faster onset of postural muscle activity during anticipatory postural adjustments may suggest a compensatory function to maintain postural control whereas the reduced postural muscle activity during APAs may indicate a pain adaptation strategy to avoid secondary damage.     

Role of the feedback signal in electromyograph biofeedback: the relevance of attention

This article describes two experiments designed to examine the hypothesis that the critical role of the feedback signal in frontalis electromyograph (EMG) biofeedback is an attentional one. In both experiments, high- and low-absorption subjects were assigned to either a biofeedback condition, a no-feedback condition, or an attentional demand condition in which external stimuli, related to relaxation, were presented as an attentional focus. The two experiments differed essentially in the type of attentional demand condition that was employed and varied the compelling nature of the demand on subjects for an external attentional focus. The pattern of results was consistent with the attentional hypothesis. For low-absorption subjects, performance in the biofeedback and attentional demand conditions was equivalent and appreciably greater than in the no-feedback condition. For high-absorption subjects, an interference effect of biofeedback was observed, but data indicated a similar interference effect on the performance of subjects when the attentional demand condition was most compelling. The pattern of results obtained point to the special relevance of attentional processes and highlight their lack of emphasis in contemporary theoretical models of EMG biofeedback.     

Effects of contextual constraint on eye movements in reading: A further examination

The effect of contextual constraint on eye movements in reading was examined by asking subjects to read sentences that contained a target word that varied in contextual constraint; high-, medium-, or low-constraint target words were used. Subjects fixated low-constraint target words longer than they did either high- or medium-constraint target words. In addition, they skipped high-constraint words more than they did either medium- or low-constraint target words. The results further confirm that contextual constraint has a strong influence on eye movements during reading.     

The course of mimetic reactions during presentation of pictures with positive, neutral and negative value

The EMG reactions of m. corrugator supercilii, m. frontalis lateralis, m. zygomaticus major and m. depressor anguli oris in 21 male subjects were recorded during a 5-second presentation of pictures with positive, negative, and neutral valence. Compared with the m. zygomaticus activity during the presentation of pictures with neutral and negative valence, the activity in the m. zygomaticus area was prolonged during the presentation of pictures with positive valence. The response curve of m. zygomaticus activity during presentation of pictures with positive valence showed a slight negative quadratic trend with maximum activity at 3 seconds after stimulus presentation. Compared with the activity during the presentation of pictures with positive and neutral valence, the activity in the m. corrugator area was prolonged during the presentation of pictures with negative valence. The response curve of m. corrugator activity during presentation of pictures with negative valence showed a tendency toward a negative quadratic trend with maximum activity at 3 seconds after stimulus presentation. During the presentation of all pictures the activity in the m. frontalis area yielded a strong negative linear trend with maximum activity in the first second after stimulus presentation. This might be attributed to the phenomenon of "habituation." Interestingly, after the presentation of pictures with negative valence, the response curve of m. frontalis activity showed a diminished linear trend compared with the linear trends after presentation of pictures with positive and neutral valence. This might be attributed to the phenomenon of "defensive reaction."     

‘Something in the way you move’: Infants are sensitive to emotions conveyed in action kinematics

Body movements, as well as faces, communicate emotions. Research in adults has shown that the perception of action kinematics has a crucial role in understanding others’ emotional experiences. Still, little is known about infants’ sensitivity to body emotional expressions, since most of the research in infancy focused on faces. While there is some first evidence that infants can recognize emotions conveyed in whole‐body postures, it is still an open question whether they can extract emotional information from action kinematics. We measured electromyographic (EMG) activity over the muscles involved in happy (zygomaticus major, ZM), angry (corrugator supercilii, CS) and fearful (frontalis, F) facial expressions, while 11‐month‐old infants observed the same action performed with either happy or angry kinematics. Results demonstrate that infants responded to angry and happy kinematics with matching facial reactions. In particular, ZM activity increased while CS activity decreased in response to happy kinematics and vice versa for angry kinematics. Our results show for the first time that infants can rely on kinematic information to pick up on the emotional content of an action. Thus, from very early in life, action kinematics represent a fundamental and powerful source of information in revealing others’ emotional state.     

Comparative effectiveness of patterned biofeedback vs meditation training on EMG and skin temperature changes

This study examined whether a low arousal, relaxation pattern of frontalis EMG decreases and peripheral skin temperature increases could be attained more effectively through biofeedback or meditation training. Thirty female subjects, ranging in age from 21 to 59, were randomly assigned to one of three groups: patterned biofeedback, clinically standardized meditation or control. Prior to training, subjects were administered the EPI. Each subject was seen weekly for seven sessions. Subjective experiences and time spent practising at home were also recorded. Repeated measures ANCOVA's performed on the EMG and skin temperature means indicated that the meditation group showed significantly lower EMG levels at the end of treatment than the control group. No group had significant temperature increases nor were there any significant differences in practice time. The biofeedback group had difficulty in patterning the two feedback signals simultaneously. Extraverts in the control group had the highest EMG levels. The most positive subjective reports came from subjects in the meditation group. Meditation offers a viable alternative as a relaxation procedure, requiring little time to learn and devoid of any performance criteria levels.     

Studying overt word reading and speech production with event-related fMRI: a method for detecting, assessing, and correcting articulation-induced signal changes and for measuring onset time and duration of articulation

A quantitative method is introduced for detecting and correcting artifactual signal changes in BOLD time series data arising from the magnetic field warping caused by motion of the articulatory apparatus when speaking aloud, with extensions to detection of subvocal articulatory activity during silent reading. Whole-head images allow the large, spike-like signal changes from the moving tongue and other components of the articulatory apparatus to be detected and localized in time, providing a measure of the time of vocalization onset, the vocalization duration, and also an estimate of the magnitude and shape of the signal change resulting from motion. Data from brain voxels are then examined during the vocalization period, and statistical outliers corresponding to contamination from articulatory motion are removed and replaced by linear interpolation from adjacent, uncontaminated data points. This quantitative approach to cleansing brain time series data of articulatory-motion-induced artifact is combined with a pre-scanning training regimen that reduces gross head movement during reading aloud to the levels observed during reading silently, which can be corrected with available image registration techniques. The combination of quantitative analysis of articulatory motion artifacts and pre-scanning training makes possible a much wider range of tasks involving overt speech than are currently being used in fMRI studies of language and cognition, as well as characterization of subvocal movements of the articulatory apparatus that are relevant to theories of reading skill, verbal rehearsal in working memory, and problem solving.     

The role of peripheral vision in implicit contextual cuing

Implicit contextual cuing refers to the ability to learn the association between contextual information of our environment and a specific target, which can be used to guide attention during visual search. It was recently suggested that the storage of a snapshot image of the local context of a target underlies implicit contextual cuing. To make such a snapshot, it is necessary to use peripheral vision. In order to test whether peripheral vision can underlie implicit contextual cuing, we used a covert visual search task, in which participants were required to indicate the orientation of a target stimulus while foveating a fixation cross. The response times were shorter when the configuration of the stimuli was repeated than when the configuration was new. Importantly, this effect was still found after 10 days, indicating that peripherally perceived spatial context information can be stored in memory for long periods of time. These results indicate that peripheral vision can be used to make a snapshot of the local context of a target.     

Does contextual cuing guide the deployment of attention?

Contextual cuing experiments show that when displays are repeated, reaction times to find a target decrease over time even when observers are not aware of the repetition. It has been thought that the context of the display guides attention to the target. The authors tested this hypothesis by comparing the effects of guidance in a standard search task with the effects of contextual cuing. First, in standard search, an improvement in guidance causes search slopes (derived from Reaction Time x Set Size functions) to decrease. In contrast, the authors found that search slopes in contextual cuing did not become more efficient over time (Experiment 1). Second, when guidance was optimal (e.g., in easy feature search), they still found a small but reliable contextual cuing effect (Experiments 2a and 2b), suggesting that other factors, such as response selection, contribute to the effect. Experiment 3 supported this hypothesis by showing that the contextual cuing effect disappeared when the authors added interference to the response selection process. Overall, the data suggest that the relationship between guidance and contextual cuing is weak and that response selection can account for part of the effect.     

Contextual questions prevent mood primes from maintaining experimentally induced dysphoria

We investigated the effects of questions designed to increase a wider awareness of the context in which moods occur on mood-maintaining primes in induced dysphoria. These questions were incorporated, with the primes (negative Velten mood induction statements) into a scrambled sentence task. In Study 1, contextual questions produced a significantly greater reduction in despondency compared to control questions. Study 2 replicated this finding and also demonstrated that contextual questions reduced corrugator EMG response to repeated despondency-inducing statements. The results indicate that contextual questions can prevent negative primes from maintaining depressed mood, consistent with Brewin's (1989) suggestion that one mechanism of psychotherapy is reducing the activation of situationally accessible negative representations.