***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: OBJECTIVES Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in sleep deprived individuals , but it is not clear whether these medications are effective at restoring higher order complex cognitive capacities such as planning , sequencing , and decision making . DESIGN After 44 hours awake , participants received a double-blind dose of one of 3 stimulant medications or placebo . After 45 - 50 hours awake , participants were tested on computerized versions of the 5-Ring Tower of Hanoi ( TOH ) , the Tower of London ( TOL ) , and the Wisconsin Card Sorting Test ( WCST ) .  SETTING In-residence sleep-laboratory facility at the Walter Reed Army Institute of Research . PARTICIPANTS Fifty-four healthy adults ( 29 men , 25 women ) , ranging in age from 18 to 36 years . INTERVENTIONS Participants were r and omly assigned to 1 of 3 stimulant medication groups , including caffeine , 600 mg ( n=12 ) , modafinil , 400 mg ( n=12 ) , dextroamphetamine , 20 mg ( n=16 ) , or placebo ( n=14 ) . MEASUREMENTS AND RESULTS At the doses tested , modafinil and dextroamphetamine groups completed the TOL task in significantly fewer moves than the placebo group , and the modafinil group demonstrated greater deliberation before making moves . In contrast , subjects receiving caffeine completed the TOH in fewer moves than all 3 of the other groups , although speed of completion was not influenced by the stimulants . Finally , the modafinil group outperformed all other groups on indices of perseverative responding and perseverative errors from the WCST . CONCLUSIONS Although comparisons across tasks can not be made due to the different times of administration , within-task comparisons suggest that , at the doses tested here , each stimulant may produce differential advantages depending on the cognitive dem and s of the task BACKGROUND AND PURPOSE Prolonged wakefulness impairs sustained vigilant attention , measured with the psychomotor vigilance task ( PVT ) , and induces a compensatory increase in sleep intensity in recovery sleep , quantified by slow‐wave activity ( SWA ) in the sleep electroencephalogram ( EEG ) . These effects of sleep deprivation are counteracted by the adenosine receptor antagonist caffeine , implying involvement of the adenosine neuromodulator/receptor system . To examine a role for adenosine A2A receptors , we investigated whether variation of the A2A receptor gene ( ADORA2A ) modified effects of caffeine on PVT and SWA after sleep deprivation Historical evidence suggests that sleep deprivation affects temporal memory , but this has not been studied systematic ally . We explored the effects of 36 hr of sleep deprivation on a neuropsychological test of temporal memory . To promote optimal performance , the test was short , novel , and interesting , and caffeine was used to reduce “ sleepiness ” . A total of 40 young adults were r and omized into four groups : control + caffeine ( Cc ) , control + placebo ( Cp ) , sleep deprived + caffeine ( SDc ) , and  sleep deprived + placebo ( SDp ) . Controls slept normally . Caffeine ( 350 mg ) or placebo were given just prior to testing . The task comprised colour photographs of unknown faces and had two components : recognition memory ( distinction between previously presented and novel faces ) , and recency discrimination ( temporal memory ) , when a previously shown face was presented . An interpolated task , self-ordered pointing , acted as a distraction . Caffeine had no effects within control conditions , but significantly reduced subjective sleepiness in SDc . Recognition was unaffected by sleep deprivation , whereas for recency , sleep deprivation groups scored significantly lower than controls . There was no significant improvement of recency with caffeine in the SDc group . Both sleep deprivation groups had poorer insight into their performance with recency . Self-ordered pointing remained unchanged . In conclusion , sleep deprivation impairs temporal memory ( i.e. recency ) despite other conditions promoting optimal performance The present study assessed the effects of mild dehydration on cognitive performance and mood of young males . A total of twenty-six men ( age 20·0 ( sd 0·3 ) years ) participated in three r and omised , single-blind , repeated- measures trials : exercise-induced dehydration plus a diuretic ( DD ; 40 mg furosemide ) ; exercise-induced dehydration plus placebo containing no diuretic ( DN ) ; exercise while maintaining euhydration plus placebo ( EU ; control condition ) . Each trial included three 40 min treadmill walks at 5·6 km/h , 5 % grade in a 27·7 ° C environment . A comprehensive computerised six-task cognitive test battery , the profile of mood states question naire and the symptom question naire ( headache , concentration and task difficulty ) were administered during each trial . Paired t tests compared the DD and DN trials result ing in > 1 % body mass loss ( mean 1·59 ( sd 0·42 ) % ) with the volunteer 's EU trial ( 0·01 ( sd 0·03 ) % ) . Dehydration de grade d specific aspects of cognitive performance : errors increased on visual vigilance ( P = 0·048 ) and visual working memory response latency slowed ( P = 0·021 ) . Fatigue and tension/anxiety increased due to dehydration at rest ( P = 0·040 and 0·029 ) and fatigue during exercise ( P = 0·026 ) . Plasma osmolality increased due to dehydration ( P < 0·001 ) but resting gastrointestinal temperature was not altered ( P = 0·238 ) . In conclusion , mild dehydration without hyperthermia in men  induced adverse changes in vigilance and working memory , and increased tension/anxiety and fatigue Overwhelming evidence shows the quality of reporting of r and omised controlled trials ( RCTs ) is not optimal . Without transparent reporting , readers can not judge the reliability and validity of trial findings nor extract information for systematic review s. Recent method ological analyses indicate that inadequate reporting and design are associated with biased estimates of treatment effects . Such systematic error is seriously damaging to RCTs , which are considered the gold st and ard for evaluating interventions because of their ability to minimise or avoid bias . A group of scientists and editors developed the CONSORT ( Consoli date d St and ards of Reporting Trials ) statement to improve the quality of reporting of RCTs . It was first published in 1996 and up date d in 2001 . The statement consists of a checklist and flow diagram that authors can use for reporting an RCT . Many leading medical journals and major international editorial groups have endorsed the CONSORT statement . The statement facilitates critical appraisal and interpretation of RCTs . During the 2001 CONSORT revision , it became clear that explanation and elaboration of the principles underlying the CONSORT statement would help investigators and others to write or appraise trial reports . A CONSORT explanation and elaboration article was published in 2001 alongside the 2001 version of the CONSORT statement . After an expert meeting in January 2007 , the CONSORT statement has been further revised and is published as the CONSORT 2010 Statement . This up date improves the wording and clarity of the previous checklist and incorporates recommendations related to topics that have only recently received recognition , such as selective outcome reporting bias . This explanatory and elaboration document-intended to enhance the use , underst and ing , and dissemination of the CONSORT statement-has also been extensively revised . It presents the meaning and rationale for each new and up date d checklist item providing examples of good reporting and , where possible , references to relevant empirical studies . Several examples of flow diagrams are included . The CONSORT 2010 Statement , this revised explanatory and elaboration document , and the associated website ( www.consort-statement.org ) should be helpful re sources to improve reporting of r and omised trials This study investigated the effects of caffeine on repeated , anaerobic exercise using a double-blind , r and omized , crossover design . Seventeen subjects ( five female ) underwent cognitive ( reaction time , number recall ) and blood ( glucose , potassium , catecholamines , lactate ) testing before and after consuming caffeine ( 6 mg/kg ) , placebo  ,  or nothing ( control ) . An exercise test ( two 60 s maximal cycling bouts ) was conducted 90 min after caffeine/placebo consumption . Plasma caffeine concentrations significantly increased after caffeine ingestion , however , there were no positive effects on cognitive or blood parameters except a significant decrease in plasma potassium concentrations at rest . Potentially negative effects of caffeine included significantly higher blood lactate compared to control and significantly slower time to peak power in exercise bout 2 compared to control and placebo . Caffeine had no significant effect on peak power , work output , RPE , or peak heart rate . In conclusion , caffeine had no ergogenic effect on repeated , maximal cycling bouts and may be detrimental to anaerobic performance Chewing has been shown to alleviate feelings of sleepiness and improve cognitive performance during the day . This study investigated the effect of chewing on alertness and cognitive performance across one night without sleep as well as the possible mediating role of cardiac autonomic activity . Fourteen adults participated in a r and omized , counterbalanced protocol employing a chewing , placebo and caffeine condition . Participants completed tasks assessing psychomotor vigilance , tracking , grammatical reasoning , alertness and sleepiness each hour across the night . All participants received either placebo or caffeine ( 200 mg ) , while the chewing condition also chewed on a tasteless and odorless substance for 15 min each hour . Heart rate ( HR ) , root mean square of the successive differences in R-R intervals on the ECG ( RMSSD ) , and preejection period ( PEP ) were simultaneously recorded . Alertness and cognitive performance amongst the chewing condition did not differ or were in fact worse when compared with placebo . Similarly , measures of HR and RMSSD remained the same between these two conditions ; however , PEP was reduced in the later part of the night in the chewing condition compared with a relative increase for placebo . Caffeine led to improved speed and accuracy on cognitive tasks and increased alertness when compared with chewing .  Relative increases in RMSSD and reductions in HR were demonstrated following caffeine ; however , no change in PEP was seen . Strong associations between cardiac parasympathetic activity and complex cognitive tasks , as well as between subjective alertness and simpler cognitive tasks , suggest a differential process mediating complex versus simple cognitive performance during sleep deprivation Neurophysiological and functional imaging studies have demonstrated that frontal regions of the brain are particularly responsive to homeostatic sleep pressure . Previous neuropsychological studies indicate that sleep deprivation causes impairments in prefrontal cortical function . R and om number generation ( RNG ) is thought to provide a sensitive index of executive functions that rely on the prefrontal cortex . The present study tested the hypothesis that sleep deprivation would impair RNG and that caffeine would mitigate this impairment . Healthy young men ( n = 21 ) participated in two 40-h sleep deprivations 1 week apart . During each sleep deprivation period subjects received either caffeine or placebo according to a r and omized , double-blind cross-over design , and they completed an oral RNG task at 3-h intervals . Comparison of test sessions at analogous times of day revealed that sleep deprivation was associated with significant drops in the number of responses , a threefold increase in the percentage of rule violations , 59 % greater response redundancy and a 20 % increase in stereotypy of adjacent response pairs . Sleep deprivation did not consistently alter counting tendency . Caffeine ameliorated the decrease in the number of responses but did not mitigate other deficits in RNG that arose during sleep deprivation . These findings are consistent with prior reports of diminished vigilance and increased perseveration during extended wakefulness . They support the conclusion that caffeine preserves simple aspects of cognitive performance during sleep deprivation , whereas caffeine may not prevent detrimental effects of sleep deprivation on some complex cognitive functions A long work schedule often results in sleep deprivation , sleepiness , impaired performance and fatigue . We investigated the residual effects of slow-release caffeine ( SRC ) on sleep , sleepiness and cognitive performance during a 42-hour recovery period following a 64-hour continuous wakefulness period in 16 healthy males , according to a double-blind , r and omised , placebo-controlled , crossover study . Three hundred milligrams of SRC or placebo was given twice a day at 21:00 and 9:00 during the first 48 h of wakefulness . Recovery sleep was analysed with electroencephalography ( EEG ) and wrist actigraphy ,  daytime sleepiness  with continuous EEG , sleep latency tests  and  actigraphy  and cognitive functions  with computerized tests  from the NATO AGARD STRES battery . Both drug groups exhibited almost the same sleep architecture with a rebound of slow-wave sleep during both recovery nights and of REM sleep during the second night . Wakefulness level and cognitive functions were similarly impaired in both groups on the first day of recovery and partially returned to baseline on the second . To conclude , SRC appears to have no unwanted side-effects on recovery sleep , wakefulness and cognitive performance after a long period of sleep deprivation and might therefore be a useful choice over other psychostimulants for a long work schedule Abstract Rationale . When humans are acutely exposed to multiple stressors , cognitive performance is substantially de grade d. Few practical strategies are available to sustain performance under such conditions . Objective . This study examined whether moderate doses of caffe 
    Output:
    
These findings are consistent with the conclusions reached in the 2001 IOM report .