***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: Summary Noninvasive brain stimulation has shown considerable promise for enhancing cognitive functions by the long-term manipulation of neuroplasticity [ 1–3 ] . However , the observation of such improvements has been focused at the behavioral level , and enhancements largely restricted to the performance of basic tasks . Here , we investigate whether transcranial r and om noise stimulation ( TRNS ) can improve learning and subsequent performance on complex arithmetic tasks .  TRNS of the bilateral dorsolateral prefrontal cortex ( DLPFC ) , a key area in arithmetic [ 4 , 5 ] , was uniquely coupled with near-infrared spectroscopy ( NIRS ) to measure online hemodynamic responses within the prefrontal cortex . Five consecutive days of TRNS-accompanied cognitive training enhanced the speed of both calculation- and memory-recall-based arithmetic learning . These behavioral improvements were associated with defined hemodynamic responses consistent with more efficient neurovascular coupling within the left DLPFC . Testing 6 months after training revealed long-lasting behavioral and physiological modifications in the stimulated group relative to sham controls for trained and nontrained calculation material . These results demonstrate that , depending on the learning regime , TRNS can induce long-term enhancement of cognitive and brain functions . Such findings have significant implication s for basic and translational neuroscience , highlighting TRNS as a viable approach to enhancing learning and high-level cognition by the long-term modulation of neuroplasticity Objective : To investigate the safety and efficacy of intermittent theta-burst stimulation ( iTBS ) in the treatment of motor symptoms in Parkinson disease ( PD ) .  Background : Progression of PD is characterized by the emergence of motor deficits , which eventually respond less to dopaminergic therapy and pose a therapeutic challenge . Repetitive transcranial magnetic stimulation ( rTMS ) has shown promising results in improving gait , a major cause of disability , and may provide a therapeutic alternative . iTBS is a novel type of rTMS that may be more efficacious than conventional rTMS . Methods : In this r and omized , double-blind , sham-controlled study , we investigated safety and efficacy of iTBS of the motor and dorsolateral prefrontal cortices in 8 sessions over 2 weeks ( evidence Class I ) . Assessment of safety and clinical efficacy over a 1-month period included timed tests of gait and bradykinesia , Unified Parkinson 's Disease Rating Scale ( UPDRS ) , and additional clinical , neuropsychological , and neurophysiologic measures . Results : We investigated 26 patients with mild to moderate PD : 13 received iTBS and 13 sham stimulation . We found beneficial effects of iTBS on mood , but no improvement of gait , bradykinesia , UPDRS , and other measures . EEG/EMG monitoring recorded no pathologic increase of cortical excitability or epileptic activity . Few reported discomfort or pain and one experienced tinnitus during real stimulation . Conclusion : iTBS of the motor and prefrontal cortices appears safe and improves mood , but failed to improve motor performance and functional status in PD . Classification of evidence : This study provides Class I evidence that iTBS was not effective for gait , upper extremity bradykinesia , or other motor symptoms in PD Repetitive transcranial magnetic stimulation ( rTMS ) is a valuable probe of brain function . Ever since its adoption as a research tool , there has been great interest regarding its potential clinical role . Presently , it is unclear whether rTMS will have some role as an alternative treatment for neuropsychiatric and neurological disorders such as Parkinson 's disease ( PD ) . To date , studies addressing the contribution of placebo during rTMS are missing . The placebo effect has been shown to be associated either with release of dopamine in the striatum or with changes in brain glucose metabolism . The main objective of this study was to test whether , in patients with PD , the expectation of therapeutic benefit from rTMS , which actually was delivered only as sham rTMS ( placebo-rTMS ) induced changes in striatal [ 11C ] raclopride binding potentials ( BP ) as measured with positron emission tomography ( PET ) .  Placebo-rTMS induced a significant bilateral reduction in [ 11C ] raclopride BP in dorsal and ventral striatum as compared to the baseline condition . This reduction BP is indicative of an increase in dopamine neurotransmission . The changes in [ 11C ] raclopride binding were more evident in the hemisphere contralateral to the more affected side supporting the hypothesis that the more severe the symptoms , the greater the drive for symptom relief , and therefore the placebo response . This is the first study addressing the placebo contribution during rTMS . While our results seem to confirm earlier evidence that expectation induces dopaminergic placebo effects , they also suggest the importance of placebo-controlled studies for future clinical trials involving brain stimulation techniques Objective . To investigate the safety and efficacy of 50-Hz repetitive transcranial magnetic stimulation ( rTMS ) in the treatment of motor symptoms in  Parkinson disease ( PD ) . Background . Progression of PD is characterized by the emergence of motor deficits that gradually respond less to dopaminergic therapy . rTMS has shown promising results in improving gait , a major cause of disability , and may provide a therapeutic alternative . Prior controlled studies suggest that an increase in stimulation frequency might enhance therapeutic efficacy . Methods . In this r and omized , double blind , sham-controlled study , the authors investigated the safety and efficacy of 50-Hz rTMS of the motor cortices in 8 sessions over 2 weeks . Assessment of safety and clinical efficacy over a 1-month period included timed tests of gait and bradykinesia , Unified Parkinson ’s Disease Rating Scale ( UPDRS ) , and additional clinical , neurophysiological , and neuropsychological parameters . In addition , the safety of 50-Hz rTMS was tested with electromyography-electroencephalogram ( EMG-EEG ) monitoring during and after stimulation . Results . The authors investigated 26 patients with mild to moderate PD : 13 received 50-Hz rTMS and 13 sham stimulation . The 50-Hz rTMS did not improve gait , bradykinesia , and global and motor UPDRS , but there appeared a short-lived “ on”-state improvement in activities of daily living ( UPDRS II ) . The 50-Hz rTMS lengthened the cortical silent period , but other neurophysiological and neuropsychological measures remained unchanged . EMG/EEG recorded no pathological increase of cortical excitability or epileptic activity . There were no adverse effects . Conclusion . It appears that 50-Hz rTMS of the motor cortices is safe , but it fails to improve motor performance and functional status in PD . Prolonged stimulation or other techniques with rTMS might be more efficacious but need to be established in future research Based on several open-label and case studies , repetitive transcranial magnetic stimulation ( rTMS ) seems to have an antidepressive effect on patients with Parkinson 's disease ( PD ) . However , this hypothesis requires further confirmation . We conducted a r and omized , double-blind placebo-controlled study to evaluate the effect of rTMS over the left dorsolateral prefrontal cortex ( DLPFC ) on depression and various motor and nonmotor features of PD . Twenty-two PD patients with mild or moderate depressive episodes were assigned into two groups , one receiving real-rTMS ( 90 % of resting motor threshold , 5 Hz , 600 pulses-a-day for 10 days ) over the left DLPFC , and another group receiving sham-rTMS . An investigator blinded to the treatment performed three video-taped examinations on each patient : before stimulation ( baseline ) , 1 day ( short term ) , and 30 days after treatment session ended ( long-term effect ) . Mini-Mental State Examination , Unified Parkinson 's Disease Rating Scale ( UPDRS ) , Hoehn-Yahr , Epworth Sleepiness , Visual Analog and Montgomery-Asberg Depression Rating Scales ( MADRS ) , Beck Depression Inventory ( BDI ) , and Trail making and Stroop tests were applied . In the actively treated group , not only depression rating scales showed significant improvement 30 days after treatment ended ( BDI by 44.4 % and MADRS by 26.1 % ) , but also the accuracy of Stroop test ( by 16 % ) . We could also demonstrate an insignificant improvement in UPDRS-III by 7.5 points ( 31.9 % , P = 0.06 ) . In the sham-treated group none of the examined tests and scales improved significantly after sham stimulation . Our study demonstrated the beneficial effect of the left DLPFC rTMS on depression in PD lasting at least 30 days after treatment . However , this result should be confirmed in patients with severe depression by further clinical trials Background Progression of Parkinson 's disease ( PD ) is characterised by motor deficits which eventually respond less to dopaminergic therapy and thus pose a therapeutic challenge . Deep brain stimulation has proven efficacy but carries risks and is not possible in all patients . Non-invasive brain stimulation has shown promising results and may provide a therapeutic alternative . Objective To investigate the efficacy of transcranial direct current stimulation ( tDCS ) in the treatment of PD . Design R and omised , double blind , sham controlled study . Setting Research institution . Methods The efficacy of anodal tDCS applied to the motor and prefrontal cortices was investigated in eight sessions over 2.5 weeks . Assessment over a 3 month period included timed tests of gait ( primary outcome measure ) and bradykinesia in the upper extremities , Unified Parkinson 's Disease Rating Scale ( UPDRS ) , Serial Reaction Time Task , Beck Depression Inventory , Health Survey and self- assessment of mobility . Results Twenty-five PD patients were investigated , 13 receiving tDCS and 12 sham stimulation . tDCS improved gait by some measures for a short time and improved bradykinesia in both the on and off states for longer than 3 months . Changes in UPDRS , reaction time , physical and mental well being , and self-assessed mobility did not differ between the tDCS and sham interventions . Conclusion tDCS of the motor and prefrontal cortices may have therapeutic potential in PD but better stimulation parameters need to be established to make the technique clinical ly viable . This study was publicly registered ( clinical trials.org : NCT00082342 ) Dysfunction of the basal ganglia-thalamocortical motor circuit is a fundamental model to account for motor symptoms in Parkinson 's disease ( PD ) . Using high-frequency repetitive transcranial magnetic stimulation ( rTMS ) over the supplementary motor area ( SMA ) , we investigated whether modulation of SMA excitability engenders therapeutic effects on motor symptoms in PD . In this double-blind placebo-controlled study , 99 patients were enrolled and assigned r and omly to SMA-stimulation and sham-stimulation groups . For SMA stimulation , 20 trains of 50 transcranial magnetic stimuli at 5 Hz were delivered at an intensity of 110 % active motor threshold for leg muscles in one session . The sham stimulation was 20 trains of electric stimuli given through electrodes fixed on the head to mimic the cutaneous sensation during rTMS . Each session of intervention was carried out once a week for the first 8 weeks . The SMA stimulation , in contrast to the sham stimulation , engendered significant improvements in total scores and motor scores of the Unified Parkinson 's Disease Rating Scale . Mean improvements in motor scores were 4.5 points in the SMA-stimulation group and -0.1 points in the sham-stimulation group . Results indicate that 5 Hz rTMS over SMA modestly improves motor symptoms in PD patients ; SMA is a potential stimulation site for PD treatment We studied whether one session of high-frequency repetitive transcranial magnetic stimulation ( rTMS ) applied over either the right or left dorsolateral prefrontal cortex would induce any measurable changes in the Tower of London spatial planning task performance in patients with Parkinson ’s disease ( PD ) . Ten patients with PD ( with no dementia and /or depression ) entered the r and omized , sham-stimulation-controlled study with a crossover design . Active and placebo rTMS were applied over either the left or the right dorsolateral prefrontal cortex ( in four separate sessions ) in each patient . The order of sessions was r and omized . The Tower of London task was performed prior to and immediately after each appropriate session . The “ total problem-solving time ” was our outcome measure . Only active rTMS of the right dorsolateral prefrontal cortex induced significant enhancement of the total problem-solving time , p = 0.038 . Stimulation of the left prefrontal cortex or sham stimulations induced no significant effects . Only rTMS applied over the right dorsolateral prefrontal cortex induced positive changes in the spatial planning task performance in PD , which further supports the results of functional imaging studies indicating the causal engagement of the right-sided hemispheric structures in solving the task in this patient population Proficiency in arithmetic learning can be achieved by using a multitude of strategies , the most salient of which are procedural learning ( applying a certain set of computations ) and rote learning ( direct retrieval from long-term memory ) . Here we investigated the effect of transcranial r and om noise stimulation ( tRNS ) , a non-invasive brain stimulation method previously shown to enhance cognitive training , on both types of learning in a 5-day sham-controlled training study , under two conditions of task difficulty , defined in terms of item repetition . On the basis of previous research implicating the prefrontal and posterior parietal cortex in early and late stages of arithmetic learning , respectively , sham-control 
    Output:
    
rTMS over the dorsolateral‐prefrontal cortex ( DLPFC ) result ed in significant reductions in scores of depressive symptoms with moderate to large effect sizes along with increased performance in several tests of cognitive functions .
tDCS over the DLPFC improved performance in several cognitive measures , including executive functions with large effect sizes .
Additional effects of tDCS on mood were not detectable ; however , only non‐depressed patients were assessed .