***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 AND PURPOSE : The optimal paradigm choice for language mapping in clinical fMRI studies is challenging due to the variability in activation among different paradigms , the contribution to activation of cognitive processes other than language , and the difficulties in monitoring patient performance . In this study , we compared language localization and lateralization between 2 commonly used clinical language paradigms and 3 newly design ed dual-choice semantic paradigms to define a streamlined and adequate language -mapping protocol . MATERIAL S AND METHODS : Twelve healthy volunteers performed 5 language paradigms : Silent Word Generation , Sentence Completion , Visual Antonym Pair , Auditory Antonym Pair , and Noun-Verb Association . Group analysis was performed to assess statistically significant differences in fMRI percentage signal change and lateralization index among these paradigms in 5 ROIs : inferior frontal gyrus , superior frontal gyrus , middle frontal gyrus for expressive language activation , middle temporal gyrus , and superior temporal gyrus for receptive language activation . RESULTS : In the expressive ROIs , Silent Word Generation was the most robust and best lateralizing paradigm ( greater percentage signal change and lateralization index than semantic paradigms at P < .01 and P < .05 levels , respectively ) . In the receptive region of interest , Sentence Completion and Noun-Verb Association were the most robust activators ( greater percentage signal change than other paradigms , P < .01 ) . All except Auditory Antonym Pair were good lateralizing tasks ( the lateralization index was significantly lower than other paradigms , P < .05 ) . CONCLUSIONS : The combination of Silent Word Generation and ≥1 visual semantic paradigm , such as Sentence Completion and Noun-Verb Association , is adequate to determine language localization and lateralization ; Noun-Verb Association has the additional advantage of objective monitoring of patient performance Over 90 % of people activate the left hemisphere more than the right hemisphere for language processing . Here , we show that the degree to which language is left lateralized is inversely related to the degree to which left frontal regions drive activity in homotopic right frontal regions . Lateralization was assessed in 60 subjects using functional magnetic resonance imaging ( fMRI ) activation for semantic decisions on verbal ( written words ) and nonverbal ( pictures of objects ) stimuli . Regional interactions between left and right ventral and dorsal frontal regions were assessed using dynamic causal modeling ( DCM ) , r and om-effects Bayesian model selection at the family level , and Bayesian model averaging at the connection level . We found that 1 ) semantic decisions on words and pictures modulated interhemispheric coupling between the left and right dorsal frontal regions , 2 ) activation was more left lateralized for words than pictures , and 3 ) for words only , left lateralization was greater when the coupling from the left to right dorsal frontal cortex was reduced . These results have theoretical implication s for underst and ing how left and right hemispheres communicate with one another during the processing of lateralized functions BACKGROUND AND PURPOSE : Brain tumors affecting language -relevant areas may influence language lateralization . The purpose of this study was to systematic ally investigate language lateralization in brain tumor patients using  clinical language fMRI  , comparing the results with a group of healthy volunteers . MATERIAL S AND METHODS : Fifty-seven strictly right-h and ed patients with left-hemispheric-space intracranial masses ( mainly neoplastic ) affecting either the Broca area ( n = 19 ) or Wernicke area ( n = 38 ) were prospect ively enrolled in this study . Fourteen healthy volunteers served as a control group .  St and ardized clinical language fMRI , using visually triggered sentence- and word-generation paradigms , was performed on a 1.5 T MR scanner . Semiautomated analyses of all functional data were conducted on an individual basis using BrainVoyager . A regional lateralization index was calculated for Broca and Wernicke areas separately versus their corresponding right-hemisphere homologs . RESULTS : In masses affecting the Broca area , a significant decrease in the lateralization index was found when performing word generation ( P = .0017 ) , whereas when applying sentence generation , the decrease did not reach statistical significance ( P = .851 ) . Masses affecting the Wernicke area induced a significant decrease of the lateralization index when performing sentence generation ( P = .0007 ) , whereas when applying word generation , the decrease was not statistically significant ( P = .310 ) . CONCLUSIONS : Clinical language fMRI was feasible for patients with brain tumors and provided relevant presurgical information by localizing essential language areas and determining language dominance . A significant effect of the brain masses on language lateralization was observed , with a shift toward the contralesional , nondominant hemisphere . This may reflect compensatory mechanisms of the brain to maintain communicative abilities Background Functional magnetic resonance imaging ( fMRI ) continues to develop as a clinical tool for patients with brain cancer , offering data that may directly influence surgical decisions . Unfortunately , routine integration of preoperative fMRI has been limited by concerns about reliability . Many pertinent studies have been undertaken involving healthy controls , but work involving brain tumor patients has been limited . To develop fMRI fully as a clinical tool , it will be critical to examine these reliability issues among patients with brain tumors . The present work is the first to extensively characterize differences in activation map quality between brain tumor patients and healthy controls , including the effects of tumor grade and the chosen behavioral testing paradigm on reliability outcomes . Method Test-retest data were collected for a group of low- grade ( n = 6 ) and high- grade glioma ( n = 6 ) patients , and for matched healthy controls ( n = 12 ) , who performed motor and language tasks during a single fMRI session . Reliability was characterized by the spatial overlap and displacement of brain activity clusters , BOLD signal stability , and the laterality index . Significance testing was performed to assess differences in reliability between the patients and controls , and low- grade and high- grade patients ; as well as between different fMRI testing paradigms . Results There were few significant differences in fMRI reliability measures between patients and controls . Reliability was significantly lower when comparing high- grade tumor patients to controls , or to low- grade tumor patients . The motor task produced more reliable activation patterns than the language tasks , as did the rhyming task in comparison to the phonemic fluency task . Conclusion In low- grade glioma patients , fMRI data are as reliable as healthy control subjects . For high- grade glioma patients , further investigation is required to determine the underlying causes of reduced reliability . To maximize reliability outcomes , testing paradigms should be carefully selected to generate robust activation patterns The aim of this work was to determine whether productive and perceptive language functions are differentially affected in homogeneous groups of epilepsy patients with right and left temporal lobe epilepsy ( TLE ) . Eighteen patients with left TLE , 18 with right TLE , and 17 healthy volunteers were studied using fMRI during performance of three tasks assessing the productive and perceptive aspects of language ( covert semantic verbal fluency , covert sentence repetition , and story listening ) . Hemispheric dominance for language was calculated in the frontal and temporal regions using laterality indices ( LI ) . Atypical lateralization was defined as a right-sided LI ( LI<-0.20 ) in the frontal lobes during the verbal fluency task or in the temporal lobes during the story listening task . Control subjects and right TLE patients demonstrated a strong left lateralization for language in the frontal lobes during the fluency task , whereas activation was less lateralized to the left hemisphere in left TLE patients , although the difference did not reach significance . In the story listening and the repetition tasks , activation was significantly more right sided in the temporal lobes of patients with left TLE . Atypical language representation was found in 19 % of TLE patients ( five left and two right TLE ) . The shift toward the right hemisphere was significantly larger in the temporal than the frontal lobes in patients with atypical language lateralization compared to TLE patients with a typical language lateralization . Neuropsychological performances of patients with atypical language patterns were better than those of patients with typical patterns , suggesting that this reorganization may represent a compensatory mechanism Atypical , right-hemisphere language dominance is poorly understood . It is often observed in patients with brain reorganization due to lesions early in life . It can also be encountered in seemingly normal individuals . We compared the patterns of neural language activation in 7 individuals with left- and 7 with right-hemisphere language dominance , none of whom had any evidence of brain lesions . We speculated that incongruencies in the activation patterns in atypical , right-hemisphere language dominance could indicate a reorganized neural language system after undetected early brain damage . Functional magnetic resonance imaging analysis of brain activation during phonetic word generation demonstrated ( 1 ) . no increased activation in the subdominant hemisphere in right compared to left language dominance , ( 2 ) . a similar variability in the pattern of activation in both groups , and ( 3 ) . a mirror reverse pattern of activation in right- compared to left-hemisphere dominant subjects . These findings support the view that in individuals with an unrevealing medical history right-hemispheric dominance constitutes a natural rather than an abortive variant of language lateralization BACKGROUND AND PURPOSE : Functional MR imaging ( fMRI ) is used to determine preoperatively the laterality of cortical language representation along with the relationship of language areas to adjacent brain tumors . The purpose of this study was to determine whether changing the statistical threshold for different language tasks influences the language laterality index ( LI ) for a group of controls , patients with tumor without prior surgery , and patients with tumor and prior surgery . MATERIAL S AND METHODS : Seven controls , 9 patients with tumor without prior surgery , and 4 patients with tumor and prior surgery performed verb-generation , phonemic fluency , and semantic fluency language tasks during fMRI .  Interhemispheric activation differences between the left and right Broca regions of interest were determined by calculating language LIs . LIs were compared within each group , between groups , and between language tasks . Intraoperative electrocortical mapping  or the presence of aphasia during postoperative neurology examinations or both were used as ground truth . RESULTS : The language LI varied as a result of statistical thresholding , presence of tumor , prior surgery , and language task . Although patients and controls followed a similar shape in the LI curve , there was no optimal P value for determining the LI . Three patients demonstrated a shift in the LI between hemispheres as a function of statistical threshold . Verb generation was the least variable task both between tasks and across groups . CONCLUSION : For preoperative patients with tumor , the LI should be examined across a spectrum of P values and a range of tasks to ensure reliability . Our data suggest that the LI may be threshold- and task-dependent , particularly in the presence of adjacent tumor RATIONALE AND OBJECTIVES The aim of this study was to assess the intrasubject and intersubject reproducibility of functional magnetic resonance imaging ( fMRI ) language paradigms on language localization and lateralization . MATERIAL S AND METHODS Fourteen healthy volunteers were enrolled prospect ively and underwent language fMRI using visually triggered covert and overt sentence generation ( SG ) and word generation ( WG ) paradigms . Semiautomated analysis of all functional data was performed using Brain Voyager on an individual basis . Regions of interest for Broca 's area , Wernicke 's area , and their contralateral homologues were drawn . The Euclidean coordinates of the center of gravidity ( x , y , and z ) of the respective blood oxygenation level-dependent ( BOLD ) activation cluster , and the correlation of the measured hemodynamic response to the applied reference function ( r ) , relative BOLD signal change as BOLD signal characteristics were measured in each region of interest . Regional lateralization indexes were calculated for Broca 's area , Wernicke 's area , and their contralateral homologues separately . Wilcoxon 's signed-rank test was applied for statistical comparisons ( P values < .05 were considered significant ) . Ten of the 14 volunteers had three repeated measurements to test intrasession reproducibility and intersession reproducibility . RESULTS Overall activation rates for the four paradigms were 89 % for covert SG , 82 % for overt SG , 89 % for covert WG , and 100 % for overt WG . When comparing covert and overt paradigms , language localization was significantly different in 17 % ( Euclidean coordinates ) and 19 % ( BOLD signal characteristics ) , respectively . Language lateralization was significantly different in 75 % . Intrasubject and intersubject reproducibility was excellent , with 3.3 % significant differences among all five parameters for language localization and 0 % significant differences for language lateralization using covert paradigms . CONCLUSIONS Covert language paradigms ( SG and WG ) provided highly robust and reproducible localization and lateralization of essential language centers for scans performed on the same and different days . Their overt counterparts achieved confirmatory localization but lower lateralization capabilities . Reference data for presurgical application are provided 
    Output:
    
Recommendations are made with a view to informing future research to increase st and ardisation in fMRI laterality protocol s. In particular , the findings reinforce the importance of threshold-independent methods for calculating laterality indices , and the benefits of assessing heterogeneity of language laterality across multiple regions of interest and tasks .