***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: Dopamine is known to regulate food intake by modulating food reward via the mesolimbic circuitry of the brain . The objective of this study was to compare the effects of high energy input ( i.v . glucose ) on striatal and thalamic dopamine release in overweight and lean individuals . We hypothesized that glucose would induce dopamine release and positive ratings ( e.g. , satiety ) in Behavioral Analog Scales , particularly in food-deprived lean subjects .  [(11)C]raclopride PET was performed for 12 lean ( mean BMI = 22 kg/m(2 ) ) and 12 overweight ( mean BMI = 33 kg/m(2 ) ) healthy subjects . Each subject was imaged twice in a blinded counter-balanced setting , after 300 mg/kg i.v . glucose and after i.v . placebo .  Dopamine D2 receptor binding potentials ( BPs ) were estimated . The voxel-based analysis of the baseline scans indicated lower striatal BPs in the overweight group and a negative correlation between BMI s and BPs . Intravenous glucose  did not have a significant effect on BPs in overweight or lean subjects ( male and female groups combined ) . However , BP changes were opposite in the two gender groups . In male subjects , significant BP reductions after glucose were seen in the right and left cau date nucleus , left putamen , and right thalamus . In female subjects , increases in BP secondary to glucose were seen in the right cau date nucleus and right and left putamen . The sexually dimorphic effect of glucose  was seen in both overweight and lean subjects . Although gender differences were not among the a priori hypotheses of the present study and , therefore , they must be considered to be preliminary findings , we postulate that this observation is a reflection of an interaction between glucose , sex steroids ( estrogen ) , leptin , and dopamine OBJECTIVE This study investigated the impact of the social modeling of side effects following placebo medication ingestion on the nocebo and placebo effect . It also investigated whether medication br and ing ( br and or generic labeling ) moderated social modeling effects . METHOD Eighty-two university students took part in the study which was purportedly investigating the impact of fast-acting beta-blocker medications ( actually placebos ) on preexamination anxiety . After taking the medication , participants were r and omized to either witness a female confederate report experiencing side effects or no side effects after taking the same medication . Differences in symptom reporting , blood pressure , heart rate , and anxiety were assessed between the social modeling of side effects and no modeling groups . RESULTS Seeing a female confederate report side effects reduced the placebo effect in systolic ( p = .009 ) and diastolic blood pressure ( p = .033 ) . Seeing a female confederate report side effects also increased both total reported symptoms ( mean [ SE ] 7.35 [ .54 ] vs. 5.16 [ 0.53 ] p = .005 ) and symptoms attributed to the medication ( 5.27 [ 0.60 ] vs. 3.04 [ 0.59 ] p = .01 ) , although the effect on symptoms was only seen in female participants . Females who saw the confederate report side effects reported approximately twice the number of symptoms as those in the no modeling group . Social modeling did not affect heart rate or anxiety . Medication br and ing did not influence placebo or nocebo outcomes . CONCLUSIONS The social modeling of symptoms can substantially reduce or eliminate the placebo effect . Viewing a female confederate display symptoms after taking the same medication increases symptom reporting in females UNLABELLED Expectations and beliefs shape the experience of pain . This is most evident in context -induced , placebo analgesia , which has recently been shown to interact with the trait of magical thinking ( MT ) in adults . In children , placebo analgesia and the possible roles that MT and gender might play as modulators of placebo analgesia have remained unexplored . Using a paradigm in which heat pain stimuli were applied to both forearms , we investigated whether MT and gender can influence the magnitude of placebo analgesia in children . Participants were 49 right-h and ed children ( aged 6 - 9 years ) who were r and omly assigned-stratified for MT and gender-to either an analgesia-expectation or a control-expectation condition . For both conditions , the placebo was a blue-colored h and disinfectant that was applied to the children 's forearms . Independent of MT , the placebo treatment significantly increased both heat pain threshold and tolerance . The threshold placebo effect was more pronounced for girls than boys . In addition , independent of the expectation treatment , low-MT boys showed a lower tolerance increase on the left compared to the right side . Finally , MT specifically modulated tolerance on the right forearm side : Low-MT boys showed an increase , whereas high-MT boys showed a decrease in heat pain tolerance . This study documented a substantial expectation-induced placebo analgesia response in children ( girls > boys ) and demonstrated MT and gender-dependent laterality effects in pain perception . The findings may help improve individualized pain management for children . PERSPECTIVE The study documents the first experimental evidence for a substantial expectancy-induced placebo analgesia response in healthy children aged 6 to 9 years ( girls > boys ) . Moreover , the effect was substantially higher than the placebo response typically found in adults . The findings may help improve individualized pain management for children Background : Expectancy and modeling have been cited as factors in mass psychogenic illness ( MPI ) , which reportedly affects more women than men . Purpose : The purpose of the study is to assess the effects of expectancy and modeling in a controlled laboratory analogue of MPI . Methods : Students were r and omly assigned to inhale or not inhale an inert placebo described as a suspected environmental toxin that had been linked to four symptoms typical of reported instances of MPI . Half of the students observed a female confederate inhale the substance and subsequently display the specified symptoms . Results : Students who inhaled the placebo reported greater increases in symptoms , and the increase was significantly greater for the specified symptoms than for other symptoms . Observation of the confederate displaying symptoms increased specified symptoms significantly among women but not among men . Changes in reported symptoms were significantly associated with changes in unobtrusively observed behavior . Conclusions : Symptoms typical of clinical reports of MPI can be induced by manipulating response expectancies , and the effects are specific rather than generalized . Among women , this effect is enhanced by observing another participant ( who in this study is also female ) display symptoms . This suggests that the preponderance of women showing symptoms in outbreaks of MPI may be due to gender-linked differences in the effects of modeling on psychogenic symptoms We examine whether overshadowing by salient stimuli is effective in reducing the ability of a certain environment ( the putative conditioned stimulus ) to evoke conditioned nausea in healthy humans that experience nausea-evoking rotation ( as the unconditioned stimulus , US ) in that environment . Twenty-four rotation-susceptible subjects ( 12 males , 12 females ) were r and omly assigned to receive either overshadowing by salient tasting beverages ( OS+ ) , or a control treatment ( a familiar beverage , water ; OS− ) prior to rotation on three consecutive days ( acquisition ) . To control for taste experiences , the alternative beverage was consumed 12 h later in the home environment ( OS+ : water , OS− : salient beverage ) . At Day 4 ( test ) , all subjects drank the familiar beverage ( water ) prior to rotation ( US ) . Rotation was st and ardized as 2 × 1-min rotation/day . Nausea was determined by a 7-item symptom scale measuring symptom number ( SN ) prior to ( anticipatory ) , immediately after , and 15 and 30 min after rotation and by the Nausea Profile ( NP ) question naire immediately after rotation . Cortisol and tumour necrosis factor (TNF)-α in saliva were sample d at the same time-points . SN and cortisol were also measured at home . Overshadowing reduced anticipatory ( conditioned ) SN . Post-rotation nausea ( i.e. the unconditioned response ) measured by the NP decreased within the OS+ group only . Anticipatory cortisol and TNF-α were not affected by overshadowing . Treatment × gender interactions manifested for post-rotation cortisol and TNF-α . Groups did not differ in SN and cortisol at home . Overshadowing is effective in reducing symptoms of anticipatory nausea and rotation-induced unconditioned nausea ; its effect on endocrine and immunological parameters is gender specific . Its application in alleviation of anticipatory nausea in cancer patients is considered Chronic neck and shoulder pain ( CNSP ) is a common musculoskeletal disorder in adults , which is linked to hypersensitivity to noxious stimuli . The hormone oxytocin has been implicated as a potential therapeutic for the management of chronic pain disorders , and has been suggested to have sex-specific effects on the salience of threatening stimuli . This study investigated the influence of intranasal oxytocin on the perception of noxious thermal stimuli .  Participants were 24 individuals with CNSP lasting > 12months ( eight women ) , and 24 age- and sex-matched healthy , pain-free controls . In a r and omised double-blind , placebo-controlled , cross-over study , participants attended two sessions , self-administering intranasal oxytocin ( 24 IU ) in one session , and placebo in another . Participants rated intensity and unpleasantness of thermal heat stimuli at three body sites : the cervical spine , deltoid , and tibialis anterior , on 11-point numerical rating scales . Compared with placebo , intranasal oxytocin increased the perceived intensity of noxious heat stimuli in women with CNSP ( Cohen 's d=0.71 ) , but not in men with CNSP , or healthy , pain-free controls . Men and women displayed divergent sensitivity across target sites for ratings of pain intensity ( partial eta squared=0.12 ) and pain unpleasantness ( partial eta squared=0.24 ) , irrespective of drug condition . Men were more sensitive at the cervical spine and deltoid , whereas women were more sensitive at the tibialis . These findings suggest that oxytocin and endogenous sex hormones may interact to influence the salience of noxious stimuli . The hyperalgesic effects of oxytocin in women suggest that caution should be taken when considering oxytocin in the management of chronic pain . TRIAL REGISTRATION CT-2016-CTN-01313 - 1 ; ACTRN12616000532404 The infusion of cytotoxic drugs in cancer patients is often accompanied by posttreatment nausea ( PN ) . In addition , patients complain about nausea prior to an infusion [ i.e. , anticipatory nausea ( AN ) ] . AN is mainly explained by classical conditioning , with the infusion as the unconditioned stimulus ( US ) and with the stimuli signaling the infusion as conditioned stimuli ( CS ) . Despite this conditioning etiology , a specifically derived therapy to attenuate the CS-US contingency is missing . The purpose of this study is to develop and to test an overshadowing procedure for prevention of AN , and also for the modification of PN intensity . Sixteen cancer patients were assigned to one of two groups : Overshadowing+ ( OV+ ) and Overshadowing- ( OV- ) . At the start of all infusions of two consecutive chemotherapy cycles A and B ( acquisition ) , OV+ subjects drank a saliently tasting beverage ( the overshadowing CS ) , whereas group OV- drank water . All patients received water in cycle C ( test ) . Self-reported symptoms and heart rates were recorded . As expected , in cycle C ( test ) , no patient of group OV+ showed AN , whereas two patients of group OV- developed AN . There was a tendency for a reduction of the intensity of PN , in terms of duration and latency after overshadowing , in cycle C : OV+ patients tended to show a shorter duration and a longer latency between end of infusion and PN onset . In OV- , there was a significantly larger heart rate deceleration in both measurement periods , in the anticipatory and the posttreatment measurement period . Data suggest to apply overshadowing for prevention of AN and modification of PN . Physiological markers of conditioned nausea are revealed . After its procedural implementation , the technique can be used in larger sample s now We conjectured that individual differences in tension-reduction alcohol outcome expectancies ( TR-AOEs ) could produce widely varying responses to manipulations in alcohol-placebo studies and tested this idea by having individuals with social phobia give speeches in front of a group . One speech occurred before and one after participants consumed either a placebo beverage or a control beverage ( i.e. , a nonalcoholic drink described as containing no alcohol ) . Study results indicate that the placebo manipulation reduced cognitive and affective symptoms of anxiety to a greater extent for males with high TR-AOEs than for males with low TR-AOEs . This pattern was not found for women in the placebo group or for individuals in the control group . These findings demonstrate a moderating effect of TR-AOEs on the association between the consumption of a  placebo beverage and response to an anxiety challenge and highlight the importance of accounting for gender and outcome expectancies when evaluating psychoactive substances Rationale In a r and omised placebo-controlled clinical trial it is assumed that psychosocial effects of the treatment , regression to the mean and spontaneous remission are identical in the drug and placebo group . Consequently , any difference between the groups can be ascribed to the pharmacological effects . Previous studies suggest that side effects of drugs can enhance expectancies of treatment effects in the drug group compared to the placebo group , and thereby increase placebo responses in the drug group compared to the placebo group . Objectives The hypothesis that side effects of drugs can enhance expectancies and placebo responses was tested . Method Painful laser stimuli were delivered to 20 healthy subjects before and after administration of 
    Output:
    
Their results can be summarized as follows : ( a ) Despite higher sensitivity of pain in females , placebo analgesia is easier to elicit in males ; ( b ) It appears that conditioning is effective specifically eliciting nocebo effects ; ( c ) Conditioning works specifically well to elicit placebo and nocebo effects in females and with nausea ; ( d ) Verbal suggestions are not sufficient to induce analgesia in women , but work in men .
These results will be discussed with respect to the question why nausea and pain may be prone to be responsive to sex/gender differences , while other symptoms are less .
Lastly , we will discuss the apparent discrepancy between RCT with low relevance of sex , and higher relevance of sex in specific experimental setting s. We argue that the placebo  response is predominantly the result of a conditioning ( learning ) response in females , while in males it predominantly may be generated via ( verbal ) manipulating of expectancies .
In RCT therefore , the net outcome of the intervention may be the same despite different mechanisms generating the placebo effect between the sexes , while in experimental work when both pathways are separated and explicitly explored , such differences may surface