***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: Background The reward value of food is partly dependent on learned associations . It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance . Objective To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink ( soft drink ) versus nutrient-rich drink ( yoghurt drink ) on reward value after repeated exposure . Design We used a r and omized crossover design whereby forty subjects ( 15 men , 25 women ) with a mean±SD age of 21±2 y and BMI of 21.5±1.7 kg/m2 consumed a fixed portion of a non-caloric sweetened ( NS ) and sugar sweetened ( SS ) versions of either a soft drink or a yoghurt drink ( counterbalanced ) for breakfast which were distinguishable by means of colored labels . Each version of a drink was offered 10 times in semi-r and om order . Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting , liking , and expected satiety . In a subgroup ( n=18 ) fMRI was performed to assess brain reward responses to the drinks . Results Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly . Overall , subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks . In addition , they expected the yoghurt drinks to be more satiating , they reduced hunger more , and delayed the first eating episode more . Conditioning did not influence these effects . Conclusion Our study showed that repeated consumption of a non-caloric sweetened beverage , instead of a sugar sweetened version , appears not to result in changes in the reward value . It can not be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period , during lifetime , affected the reward value of the drinks In this study , the representation of taste in the orbitofrontal cortex was investigated to determine whether or not a pleasant and an aversive taste have distinct or overlapping representations in this region . The pleasant stimulus used was sweet taste ( 1 M glucose ) , and the unpleasant stimulus was salt taste ( 0.1 M NaCl ) . We used an ON/OFF block design in a 3 T fMRI scanner with a tasteless solution delivered in the OFF period to control for somatosensory or swallowing-related effects . It was found that parts of the orbitofrontal cortex were activated ( P < 0.005 corrected ) by glucose ( in 6/7 subjects ) and by salt ( in 6/7 subjects ) . In the group analysis , separate areas of the orbitofrontal cortex were found to be activated by pleasant and aversive tastes . The involvement of the amygdala in the representation of pleasant as well as aversive tastes was also investigated . The amygdala was activated ( region of interest analysis , P < 0.025 corrected ) by the pleasant taste of glucose ( 5/7 subjects ) as well as by the aversive taste of salt ( 4/7 subjects ) . Activation by both stimuli was also found in the frontal opercular/insular ( primary ) taste cortex . We conclude that the orbitofrontal cortex is involved in processing tastes that have both positive and negative affective valence and that different areas of the orbitofrontal cortex may be activated by pleasant and unpleasant tastes . We also conclude that the amygdala is activated not only by an affectively unpleasant taste , but also by a taste that is affectively pleasant , thus providing evidence that the amygdala is involved in effects produced by positively affective as well as by negatively affective stimuli Vision provides a primary sensory input for food perception . It raises expectations on taste and nutritional value and drives acceptance or rejection . So far , the impact of visual food cues varying in energy content on subsequent taste integration remains unexplored . Using electrical neuroimaging , we assessed whether high- and low-calorie food cues differentially influence the brain processing and perception of a subsequent neutral electric taste . When viewing high-calorie food images , participants reported the subsequent taste to be more pleasant than when low-calorie food images preceded the identical taste . Moreover , the taste-evoked neural activity was stronger in the bilateral insula and the adjacent frontal operculum ( FOP ) within 100 ms after taste onset when preceded by high- versus low-calorie cues . A similar pattern evolved in the anterior cingulate ( ACC ) and medial orbitofrontal cortex ( OFC ) around 180 ms , as well as , in the right insula , around 360 ms . The activation differences in the OFC correlated positively with changes in taste pleasantness , a finding that is an accord with the role of the OFC in the hedonic evaluation of taste . Later activation differences in the right insula likely indicate revaluation of interoceptive taste awareness . Our findings reveal previously unknown mechanisms of cross-modal , visual-gustatory , sensory interactions underlying food evaluation Sensory-specific satiety , which is defined as a relative decrease in pleasantness , is increased by greater oro-sensory stimulation . Both sensory-specific satiety and pleasantness affect taste activation in the orbitofrontal cortex . In contrast , metabolic satiety , which results from energy intake , is expected to modulate taste activation in reward areas . The aim of this study was to determine the effects of the amount of oro-sensory stimulation and energy content on consumption-induced changes in taste activation .  Ten men participated in a 2 × 2 r and omized crossover study . Subjects were scanned twice using functional magnetic resonance imaging : after fasting for at least 2h and after treatment , on four occasions . Treatment consisted of the ingestion of 450 mL of orangeade ( sweetened with 10 % sucrose or non-caloric sweeteners ) at 150 mL/min , with either small ( 5 mL ) or large ( 20 mL ) sips . During scanning , subjects alternately tasted orangeade , milk and tomato juice and rated its pleasantness . Before and after the scans , subjects rated pleasantness , prospect i ve consumption , desire to eat and sweetness for all tastants . Main findings were that , before treatment , the amygdala was activated more by non-caloric than by caloric orangeade . Caloric orangeade activated part of the striatum before , but not after treatment . We observed no main effects of sip size on taste activation and no interaction between sip size and caloric content . In conclusion , the brain responds differentially to caloric and non-caloric versions of a sweet drink and consumption of calories can modulate taste activation in the striatum . Further research is needed to confirm that the observed differences are due to caloric content and not to ( subliminal ) differences in the sensory profile . In addition , implication s for the effectiveness of non-caloric sweeteners in decreasing energy intake need to be established Research indicates that dysfunctional food reward processing may contribute to pathological eating behaviour . It is widely recognized that both the amygdala and the orbitofrontal cortex ( OFC ) are essential parts of the brain 's reward circuitry . The aims of this fMRI study were ( 1 ) to examine the effects of food deprivation and calorie content on reward processing in the amygdala and the OFC , and ( 2 ) to examine whether an explicit evaluation of foods is necessary for OFC , but not amygdalar activity . Addressing the first aim , healthy females were presented with high and low calorie food pictures while being either hungry or satiated . For the second aim , attention focus was manipulated by directing participants ' attention either to the food or to a neutral aspect . This study shows that hunger interacts with the energy content of foods , modulating activity in the posterior cingulate cortex , medial OFC , insula , cau date putamen and fusiform gyrus . Results show that satiated healthy females show an increased reward processing in response to low calorie foods . Confirming our hypothesis , food deprivation increased activity following the presentation of high calorie foods , which may explain why treatments of obesity energy restricting diets often are unsuccessful . Interestingly , activity in both the amygdala and mOFC was only evident when participants explicitly evaluated foods . However , attention independent activity was found in the mPFC following the high calorie foods cues when participants where hungry . Current findings indicate that research on how attention modulates food reward processing might prove especially insightful in the study of the neural substrates of healthy and pathological eating behaviour BACKGROUND A preference for sweet tastes has been repeatedly shown to be associated with alcohol preference in both animals and humans . In this study , we tested the extent to which recent drinking is related to blood oxygen level-dependent ( BOLD ) activation from an intensely sweet solution in orbitofrontal areas known to respond to primary rewards . METHODS Sixteen right-h and ed , non-treatment-seeking , healthy volunteers ( mean age : 26 years ; 75 % male ) were recruited from the community . All underwent a taste test using a range of sucrose concentrations , as well as functional magnetic resonance imaging ( fMRI ) during pseudor and om , event-driven stimulation with water and a 0.83 M concentration of sucrose in water . RESULTS [ Sucrose > water ] provoked a significant BOLD activation in primary gustatory cortex and amygdala , as well as in the right ventral striatum and in bilateral orbitofrontal cortex . Drinks/drinking day correlated significantly with the activation as extracted from the left orbital area ( r = 0.52 , p = 0.04 after correcting for a bilateral comparison ) . Using stepwise multiple regression , the addition of rated sucrose liking accounted for significantly more variance in drinks/drinking day than did left orbital activation alone ( multiple R = 0.79 , p = 0.002 ) . CONCLUSIONS Both the orbitofrontal response to an intensely sweet taste and rated liking of that taste accounted for significant variance in drinking behavior . The brain response to sweet tastes may be an important phenotype of alcoholism risk 
    Output:
    
We confirm the importance of primary taste areas for gustatory processing in human adults .
We also provide tentative evidence for reward-related cau date activity in relation to the sweet taste of caloric sugars .