***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: Neuroimaging studies have demonstrated activations in the anterior cingulate cortex ( ACC ) related to the affective component of pain , but not to stimulus intensity . However , it is possible that the low spatial resolution of positron emission tomography , as used in the majority of these studies , obscured areas coding stimulus intensity . We revisited this issue , using a parametric single-trial functional magnetic resonance imaging design , and investigated pain , stimulus intensity , and stimulus awareness ( i.e. , pain unrelated ) responses within the ACC in nine healthy volunteers .  Four different stimulus intensities ranging from warm to painful ( 300–600 mJ ) were applied with a thulium yttrium – aluminum granate infrared laser in a r and omized order and rated by the subjects on a five point scale ( P0–P4 ) . Pain-related regions in the ventral posterior ACC showed a response that did not distinguish between innocuous trials ( P0 and P1 ) but showed a positive linear relationship with the blood oxygenation level-dependent contrast signal for painful trials ( P2–P4 ) . Regions in the dorsal anterior ACC along the cingulate sulcus differentiated between P0 ( not perceived ) and P1 but exhibited no additional signal increase with P2 ; these regions are related to stimulus awareness and probably to cognitive processing . Most importantly , we identified a region in the dorsal posterior ACC showing a response that discriminated between nonpainful trials ( P0 and P1 ) ; therefor , this region was simply related to basic sensory processing and not to pain intensity . Stimulus-related activations were all located adjacent to the cingulate motor area , highlighting the strategic link of stimulus processing and response generation in the posterior ACC Background Selective serotonin reuptake inhibitors ( SSRIs ) are popular medications for anxiety and depression , but their effectiveness , particularly in patients with prominent symptoms of loss of motivation and pleasure , has been question ed . There are few studies of the effect of SSRIs on neural reward mechanisms in humans . Methods We studied 45 healthy participants who were r and omly allocated to receive the SSRI citalopram , the noradrenaline reuptake inhibitor reboxetine , or placebo for 7 days in a double-blind , parallel group design . We used functional magnetic resonance imaging to measure the neural response to rewarding ( sight and /or flavor of chocolate ) and aversive stimuli ( sight of moldy strawberries and /or an unpleasant strawberry taste ) on the final day of drug treatment . Results Citalopram reduced activation to the chocolate stimuli in the ventral striatum and the ventral medial/orbitofrontal cortex . In contrast , reboxetine did not suppress ventral striatal activity and in fact increased neural responses within medial orbitofrontal cortex to reward . Citalopram also decreased neural responses to the aversive stimuli conditions in key “ punishment ” areas such as the lateral orbitofrontal cortex . Reboxetine produced a similar , although weaker effect . Conclusions Our findings are the first to show that treatment with SSRIs can diminish the neural processing of both rewarding and aversive stimuli . The ability of SSRIs to decrease neural responses to reward might underlie the question ed efficacy of SSRIs in depressive conditions characterized by decreased motivation and anhedonia and could also account for the experience of emotional blunting described by some patients during SSRI treatment The present study examined whether automaticity , defined here as independence from attentional modulation , is a fundamental principle of the neural systems specialized for processing social signals of environmental threat . Attention was focused on either scenes or faces presented in a single overlapping display .  Facial expressions were neutral , fearful , or disgusted . Amygdala responses to facial expressions of fear , a signifier of potential physical attack , were not reduced with reduced attention to faces . In contrast , anterior insular responses to facial expressions of disgust , a signifier of potential physical contamination , were reduced with reduced attention . However , reduced attention enhanced the amygdala response to disgust expressions ; this enhanced amygdala response to disgust correlated with the magnitude of attentional reduction in the anterior insular response to disgust . These results suggest that automaticity is not fundamental to the processing of all facial signals of threat , but is unique to amygdala processing of fear . Furthermore , amygdala processing of fear was not entirely automatic , coming at the expense of specificity of response . Amygdala processing is thus specific to fear only during attended processing , when cortical processing is undiminished , and more broadly tuned to threat during unattended processing , when cortical processing is diminished It is hypothesized that due to an abnormal functioning of the reward system patients with schizophrenia form context -inappropriate associations . It has been shown that the dopamine target regions , especially the ventral striatum , are critical in the formation of reward associations . We wanted to examine how the ventral striatum responds as patients learn reward-related associations and how this neural response is linked to objective and subjective behavioral measures . Functional magnetic resonance imaging ( fMRI ) Blood oxygen level dependent ( BOLD ) responses were examined using aversive Pavlovian learning in 13 medicated patients with schizophrenia and 13 matched healthy controls .  Colored circles served as conditioned stimulus ( CS+ ) while a loud , individually adjusted , noise served as the unconditioned stimulus . Circles of another color served as neutral comparators ( CS− ) . Subjective indices were assessed by a post-scan  self-report  , and  galvanic skin responses ( GSR ) were used as objective measures of associative learning . fMRI data were analyzed using a r and om effects model in SPM2 . Patients showed inappropriately strong activations in the ventral striatum in response to the neutral stimulus ( CS− ) as compared to the healthy controls . Consistent with this neural evidence of aberrant learning , patients also showed evidence of abnormal learning by self-report and as indexed by GSR . The main finding here is that patients with schizophrenia , when exposed to neutral stimuli in a threatening situation , show an abnormal pattern of learning . The aberrant activations and response are consistent with the idea that patients aberrantly assign motivational salience to neutral stimuli , and this process may be one of the aberrations that predisposes them to psychosis The experience of pain is subjectively different from the fear and anxiety caused by threats of pain . Functional magnetic resonance imaging in healthy humans was applied to dissociate neural activation patterns associated with acute pain and its anticipation . Expectation of pain activated sites within the medial frontal lobe , insular cortex , and cerebellum distinct from , but close to , locations mediating pain experience itself . Anticipation of pain can in its own right cause mood changes and behavioral adaptations that exacerbate the suffering experienced by chronic pain patients . Selective manipulations of activity at these sites may offer therapeutic possibilities for treating chronic pain Activation studies have shown that in response to evocative visual stimuli , brain activity increases in the visual cortex and limbic areas . However , non-affective characteristics of these images , such as color composition and visual complexity , confound the interpretation of these results . To address this issue , we had subjects rate over 100 images on aversive intensity ( facial mutilation , dead bodies ) and semantic complexity ( number of objects subjects could name ) . From these images , we assembled digitized image sets of non-aversive , mild and strong intensity , balanced on semantic complexity and content ( human faces and figures ) , and adjusted for color composition . A fourth condition consisted of a fixation cross on a blank screen .  Thirteen subjects underwent eight positron emission tomography scans using the [ (15)O ] water methodology . Measurement of skin conductance was recorded simultaneously . All picture conditions , relative to the blank screen , activated the amygdalae and bilateral orbitofrontal cortex , while we found activation trends associated with increasing aversive content in the sub-lenticular region . Skin conductance increased during all picture conditions . Relative to the non-aversive pictures , aversive image content caused modulation of occipital and occipital-temporal cortex . These results demonstrated activation of the amygdala to salient , arousing stimuli , and not just aversive stimuli . In addition , they suggest that pictorial complexity , as indexed by our semantic measure , does not account for the modulation of visual cortex by aversive , emotional stimuli Previous functional neuroimaging studies have characterized brain systems mediating associative learning using classical delay conditioning paradigms . In the present study , we used event-related functional magnetic resonance imaging to characterize neuronal responses mediating aversive trace conditioning . During conditioning , neutral auditory tones were paired with an aversive sound [ unconditioned stimulus ( US ) ] . We compared neuronal responses evoked by conditioned ( CS+ ) and nonconditioned ( CS− ) stimuli in which a 50 % pairing of CS+ and the US enabled us to limit our analysis to responses evoked by the CS+ alone . Differential responses  ( CS+ vs CS− ) , related to conditioning , were observed in anterior cingulate and anterior insula , regions previously implicated in delay fear conditioning . Differential responses were also observed in the amygdala and hippocampus that were best characterized with a time × stimulus interaction , indicating rapid adaptation of CS+-specific responses in medial temporal lobe . These results are strikingly similar to those obtained with a previous delay conditioning experiment and are in accord with a preferential role for medial temporal lobe structures during the early phase of conditioning . However , an additional activation of anterior hippocampus in the present experiment supports a view that its role in trace conditioning is to maintain a memory trace between the offset of the CS+ and the delayed onset of the US to enable associative learning in trace conditioning Functional neuroimaging studies in humans have shown that nociceptive stimuli elicit activity in a wide network of cortical areas commonly labeled as the " pain matrix " and thought to be preferentially involved in the perception of pain . Despite the fact that this " pain matrix " has been used extensively to build models of where and how nociception is processed in the human brain , convincing experimental evidence demonstrating that this network is specifically related to nociception is lacking . The aim of the present study was to determine whether there is at least a subset of the " pain matrix " that responds uniquely to nociceptive somatosensory stimulation . In a first experiment , we compared the fMRI brain responses elicited by a  r and om sequence of brief nociceptive somatosensory , non-nociceptive somatosensory , auditory and visual stimuli  , all presented within a similar attentional context . We found that the fMRI responses triggered by nociceptive stimuli can be largely explained by a combination of ( 1 ) multimodal neural activities ( i.e. , activities elicited by all stimuli regardless of sensory modality ) and ( 2 ) somatosensory-specific but not nociceptive-specific neural activities ( i.e. , activities elicited by both nociceptive and non-nociceptive somatosensory stimuli ) . The magnitude of multimodal activities correlated significantly with the perceived saliency of the stimulus . In a second experiment , we compared these multimodal activities to the fMRI responses elicited by auditory stimuli presented using an oddball paradigm . We found that the spatial distribution of the responses elicited by novel non-target and novel target auditory stimuli resembled closely that of the multimodal responses identified in the first experiment . Taken together , these findings suggest that the largest part of the fMRI responses elicited by phasic nociceptive stimuli reflects non nociceptive-specific cognitive processes BACKGROUND Loss aversion in decision-making refers to a higher sensitivity to losses than to gains . Loss aversion is conceived as an affective interference in cognitive processes such as judgment and decision-making . Loss aversion in non-risky choices has not been studied in schizophrenia . METHOD Forty-two individuals with schizophrenia and 42 non-patient control subjects , matched by gender and age , were r and omized to two different scenarios ( a buying scenario and a selling scenario ) . Subjects were asked to evaluate the price of a decorated mug . Schizophrenia subjects were re-tested four weeks later with the other scenario . RESULTS Contrary to non-patient controls , schizophrenia subjects did not show loss aversion . In the schizophrenia group , absence of loss aversion was correlated with age , duration of illness , number of months in State hospitals , and poorer performance in the Wisconsin Card Sorting Test , but not with current psychopathology and two domains of emotional experience . CONCLUSIONS Absence of loss aversion in schizophrenia represents a deficit in the processing of emotional information during decision-making . It can be interpreted as a lack of integration between the emotional and the cognitive systems , or to a more diffuse and de-differentiated impact of emotional information on decision-making . Future studies should bring more clarity to this question Echoplanar functional magnetic resonance imaging ( fMRI ) was used in normal human subjects to investigate the role of the amygdala in conditioned fear acquisition and extinction . A simple discrimination procedure was employed in which activation to a visual cue predicting shock ( CS+ ) was compared with activation to another cue presented alone ( CS- ) . CS+ and CS- trial types were intermixed in a pseudor and om order . Functional images were acquired with an asymmetric spin echo pulse sequence from three coronal slices centered on the amygdala . Activation of the amygdala/periamygdaloid cortex was observed during conditioned fear acquisition and extinction . The extent of activation during acquisition was significantly correlated with autonomic indices of conditioning in individual subjects . Consistent with a recent electrophysiological recording study in the rat ( Quirk et al. , 1997 ) , the profile of the amygdala response was temporally grade d , although this dynamic was only statistically reliable during extinction . These results provide further evidence for the conservation of amygdala function across species and implicate an amygdalar contribution to both acquisition and extinction processes during associative emotional learning tasks Anticipatory anxiety is a complex combination of a future-oriented cognitive state , negative affect , and autonomic arousal . A dual-task paradigm of anticipation of electric shocks and a motor-learning task was used to examine the changes in neural patterns of activation associated with modulation of the cognitive state in anxiety by a distracting motor task 
    Output:
    
Our results highlighted the recruitment of the anterior cingulate cortex , the anterior insula , and the amygdala as well as other subcortical ( e.g. , thalamus , midbrain ) and cortical ( e.g. , orbitofrontal ) regions in both animals and humans .
Importantly , involvement of these regions remained independent of sensory modality .
This study provides evidence for a core neural network mediating aversion in both animals and humans .