***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The experience of pain and disgust share many similarities , given that both are aversive experiences result ing from bodily threat and leading to defensive reactions . The aim of the present study was to investigate whether facial expressions are distinct enough to encode the specific quality of pain and disgust or whether they just encode the similar negative valence and arousal level of both states . In sixty participants pain and disgust were induced by heat stimuli and pictures , respectively . Facial responses ( Facial Action Coding System ) as well as subjective responses were assessed . Our main findings were that nearly the same single facial actions were elicited during pain and disgust experiences . However , these single facial actions were displayed with different strength and were differently combined depending on whether pain or disgust was experienced . Whereas pain was mostly encoded by contraction of the muscles surrounding the eyes ( by itself or in combination with contraction of the eyebrows ) ; disgust was mainly accompanied by contraction of the eyebrows and —in contrast to pain — by raising of the upper lip as well as the combination of upper lip raise and eyebrow contraction . Our data clearly suggests that facial expressions seem to be distinct enough to encode not only the general valence and arousal associated with these two bodily aversive experiences , namely pain and disgust , but also the specific origin of the threat to the body . This implies that the differential decoding of these two states by an observer is possible without additional verbal or context ual information , which is of special interest for clinical practice , given that raising awareness in observers about these distinct differences could help to improve the detection of pain in patients who are not able to provide a self-report of pain ( e.g. , patients with dementia ) OBJECTIVE To determine whether patterns of facial expressions of patients complaining of chest pain can aid in the diagnosis of myocardial infa rct ions . DESIGN Exploratory . SETTING Southeastern university medical center emergency department ( ED ) . PATIENTS Twenty-eight patients in the ED who presented with chest pain . Age range was 40 to 84 years , with a mean of 65.4 years . OUTCOME MEASURES Common patterns of facial expressions among patients diagnosed with myocardial infa rct ion . INTERVENTION On admission to the ED , patients were videotaped during physical examination . Videotapes were review ed to code the facial action units exhibited by the patients . The presence or absence of creatine kinase ( CK ) enzymes was determined ; these results were blinded to the coders until after all facial actions were coded . RESULTS With use of the Facial Action Coding System , 4 facial expressions were found to be associated with true myocardial infa rct ion : lowering the brow , pressing the lips , parting the lips , and turning the head left . CONCLUSION Additional research with a larger sample of patients presenting with chest pain is needed to vali date the findings of this study . However , if these findings are supported , instruction regarding assessment of specific facial expressions in clinical setting s may be warranted Abstract Although emotion regulation modulates the pain experience , inconsistencies have been identified regarding the impact of specific regulation strategies on pain . Our goal was to examine the effects of emotion suppression and cognitive re appraisal on automatic ( ie , nonverbal ) and cognitively mediated ( ie , verbal ) pain expressions . Non clinical participants were r and omized into either a suppression ( n = 58 ) , re appraisal ( n = 51 ) , or monitoring control ( n = 42 ) condition . Upon arrival to the laboratory , participants completed the Emotion Regulation Question naire , to quantify self-reported suppression and re appraisal tendencies . Subsequently , they completed a thermal pain threshold and tolerance task . They were then provided with instructions to use , depending on their experimental condition , suppression , re appraisal , or monitoring strategies . Afterward , they were exposed to experimentally induced pain .  Self-report measures of pain , anxiety , and tension were administered , and facial expressions , heart rate , and galvanic skin response were recorded . The Facial Action Coding System was used to quantify general and pain-related facial activity ( ie , we defined facial actions that occurred during at least 5 % of pain stimulation periods as “ pain-related actions ” ) . Re appraisal and suppression induction led to reductions in nonverbal and verbal indices of pain . Moreover , self-reported tendencies to use suppression and re appraisal ( as measured by the Emotion Regulation Question naire ) did not interact with experimental condition in the determination of participants ' responses . Results suggest that consciously applying emotion regulation strategies during a painful task can moderate both cognitively mediated ( eg , verbal ) and automatic ( eg , facial activity ) expressions of pain OBJECTIVE The goal was to study the utility of nonverbal facial expressions as a research tool for assessing pain in persons with intellectual disabilities . Biases and stereotypes related to age , gender , physical attractiveness , and intellectual disability that may influence the ability of observers to evaluate pain reactions were also examined . DESIGN Facial reactions to an intramuscular injection of 40 adults ( mean age = 49.6 years ) with an intellectual disability were videotaped and objective ly examined using the Facial Action Coding System . Self-reported pain ratings were obtained using a Colored Visual Analogue Scale for pain . Pain reactions were also rated by untrained observers . RESULTS A significant proportion of participants ( 35 % ) was unable to provide valid self-report . The intensity of objective ly coded facial activity as well as observer-rated pain intensity showed significant increases from baseline to injection segments . Observers ' pain ratings were primarily determined by the intensity of facial activity and were not significantly affected by stereotypes based on perceived level of intellectual disability , gender , age , or physical attractiveness . CONCLUSIONS The findings support the validity of both objective ly coded and observer-rated facial expressions of pain as research tools in treatment outcome studies involving persons with intellectual disabilities . Self-report has substantial limitations for the assessment of pain in this population 
    Output:
    
This subset of pain-related facial responses seems to encode the essential information about pain available in the face .