title: Sustaining executive functions during sleep deprivation: A comparison of caffeine, dextroamphetamine, and modafinil. Cognitive enhancing effects of modafinil in healthy volunteers The neural basis of human error processing: reinforcement learning, dopamine, and the error-related negativity. A double-blind, placebo-controlled investigation of the efficacy of modafinil for sustaining the alertness and performance of aviators: a helicopter simulator study Methylphenidate improves response inhibition in adults with attention-deficit/hyperactivity disorder Expectation to receive methylphenidate enhances subjective arousal but not cognitive performance. Neurochemical Enhancement of Conscious Error Awareness Objective and subjective cognitive enhancing effects of mixed amphetamine salts in healthy people Illicit use of specific prescription stimulants among college students: prevalence, motives, and routes of administration. Modafinil improves rapid shifts of attention Age-dependent and age-independent human memory persistence is enhanced by delayed posttraining methylphenidate administration Tryptophan depletion impairs stimulus-reward learning while methylphenidate disrupts attentional control in healthy young adults: implications for the monoaminergic basis of impulsive behaviour Effects of methylphenidate on spatial working memory and planning in healthy young adults The effect of methylphenidate on information processing Self-monitoring cognitive performance during sleep deprivation: effects of modafinil, d-amphetamine and placebo. Effect of amphetamine on long-term retention of verbal material Dextroamphetamine: cognitive and behavioral effects in normal prepubertal boys. Interaction of expectancy and the pharmacological effects ofd-amphetamine: subjective effects and self-administration Prevalence and Motives for Illicit Use of Prescription Stimulants in an Undergraduate Student Sample Dextroamphetamine. Its cognitive and behavioral effects in normal and hyperactive boys and normal men.
abstract: 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 Abstract Rationale . Modafinil , a novel wake-promoting agent , has been shown to have a similar clinical profile to that of conventional stimulants such as methylpheni date . We were therefore interested in assessing whether modafinil , with its unique pharmacological mode of action , might offer similar potential as a cognitive enhancer , without the side effects commonly experienced with amphetamine-like drugs . Objectives . The main aim of this study was to evaluate the cognitive enhancing potential of this novel agent using a comprehensive battery of neuropsychological tests . Methods . Sixty healthy young adult male volunteers received either a single oral dose of placebo , or 100 mg or 200 mg modafinil prior to performing a variety of tasks design ed to test memory and attention . A r and omised double-blind , between-subjects design was used . Results . Modafinil significantly enhanced performance on tests of digit span , visual pattern recognition memory , spatial planning and stop-signal reaction time . These performance improvements were complemented by a slowing in latency on three tests : delayed matching to sample , a decision-making task and the spatial planning task . Subjects reported feeling more alert , attentive and energetic on drug . The effects were not clearly dose dependent , except for those seen with the stop-signal paradigm . In contrast to previous findings with methylpheni date , there were no significant effects of drug on spatial memory span , spatial working memory , rapid visual information processing or attentional set-shifting . Additionally , no effects on paired associates learning were identified . Conclusions . These data indicate that modafinil selectively improves neuropsychological task performance . This improvement may be attributable to an enhanced ability to inhibit pre-potent responses . This effect appears to reduce impulsive responding , suggesting that modafinil may be of benefit in the treatment of attention deficit hyperactivity disorder The authors present a unified account of 2 neural systems concerned with the development and expression of adaptive behaviors : a mesencephalic dopamine system for reinforcement learning and a " generic " error-processing system associated with the anterior cingulate cortex . The existence of the error-processing system has been inferred from the error-related negativity ( ERN ) , a component of the event-related brain potential elicited when human participants commit errors in reaction-time tasks . The authors propose that the ERN is generated when a negative reinforcement learning signal is conveyed to the anterior cingulate cortex via the mesencephalic dopamine system and that this signal is used by the anterior cingulate cortex to modify performance on the task at h and . They provide support for this proposal using both computational modeling and psychophysiological experimentation Abstract . Rationale : In 1998 , the FDA approved modafinil for treating  excessive daytime sleepiness in narcoleptics , and this has raised questions about the appropriateness of this compound for enhancing alertness in sleep-deprived controls . This study explored the efficacy of modafinil for maintaining the performance of volunteers required to accomplish highly dem and ing tasks despite sleep loss . Objective : The principal objective was to determine whether prophylactic doses of modafinil would attenuate decrements in aviator performance and arousal throughout 2 days and 1 night without sleep . Methods : Six pilots were exposed to two 40-h periods of continuous wakefulness . In one , three 200-mg doses of modafinil were given and in the other , matching placebos were administered . Helicopter simulator flights , resting EEGs , and Profile of Mood States ( POMS ) question naires were evaluated . Results : Modafinil attenuated sleep deprivation effects on four of six flight maneuvers , reduced slow-wave EEG activity , and lessened self-reported problems with mood and alertness in comparison to placebo . The most noticeable benefits occurred between 0330 and 1130 hours , when the combined impact of sleep loss and the circadian trough was most severe . The most frequently observed drug side effects were vertigo , nausea , and dizziness . These could have been related to : 1 ) the motion-based testing , 2 ) the use of a simulator rather than an actual aircraft ( i.e. , " simulator sickness " ) , and /or 3 ) the administration of more than 400 mg modafinil . Conclusions : Modafinil is a promising countermeasure for  sleep loss in normals ; however , additional studies aim ed at reducing side effects are needed before it should be used in aviators BACKGROUND Response inhibition is an executive function that requires voluntary control over responses when there is a change of context . The right inferior frontal cortex is necessary for response inhibition , and a deficit in right frontostriatal circuitry might underlie attention-deficit/hyperactivity disorder ( ADHD ) . Many studies of childhood ADHD have demonstrated impaired response inhibition and its amelioration by methylpheni date ( MPH ) . The current study tested response inhibition and the effect of MPH in adult ADHD . METHODS Response inhibition was assessed with the " tracking " stop-signal test in 13 adults with a diagnosis of ADHD , both while taking and while not taking medication , and 13 healthy , unmedicated , age- and intelligence quotient-matched control subjects . RESULTS Stop-signal reaction time was significantly slower in unmedicated adults with ADHD relative to healthy control subjects , and this deficit was significantly ameliorated by medication . CONCLUSIONS Adult ADHD patients had a response inhibition profile similar to that produced by lesions to the right inferior frontal cortex , which was remedied by stimulant medication Nonmedical use of prescription-stimulant medication such as methylpheni date ( MPH ) has increased among college students over the past several years . Common motivations for use include enhancements in cognition and subjective arousal . As it is unclear whether stimulant medication exerts the same effect on healthy individuals as for those with attention-deficit/hyperactivity disorder , it is possible that many reported effects of prescription stimulants by healthy individuals may stem from placebo effects , which may be an important mechanism underlying initiation and maintenance of nonmedical use . This study examined whether placebo effects influence reports of subjective mood and cognitive performance among college students who endorsed several risk factors for prescription-stimulant misuse ( i.e. , low grade point average , fraternity/sorority involvement , binge drinking , cannabis use ) . Ninety-six subjects ( 60 % male ) completed cognitive tests and question naires assessing present mood state on two occasions . Forty-seven participants were r and omized to an experimental condition and orally ingested what they believed to be MPH , though actually placebo , on one visit and received no medication on the other visit . The control group received no medication on either visit . During the administration visit , experimental participants reported feeling significantly more high and stimulated compared with the nonadministration visit and to the control subjects . However , cognitive enhancement differences were not generally seen between visits or groups . This research demonstrates that placebo effects for prescription stimulants do influence subjective mood and may be implicated in nonmedical stimulant use . This knowledge may be useful in challenging prescription-stimulant-related expectancies to decrease the prevalence of use among college students How the brain monitors ongoing behavior for performance errors is a central question of cognitive neuroscience . Diminished awareness of performance errors limits the extent to which humans engage in corrective behavior and has been linked to loss of insight in a number of psychiatric syndromes ( e.g. , attention deficit hyperactivity disorder , drug addiction ) . These conditions share alterations in monoamine signaling that may influence the neural mechanisms underlying error processing , but our underst and ing of the neurochemical drivers of these processes is limited . We conducted a r and omized , double-blind , placebo-controlled , cross-over design of the influence of methylpheni date , atomoxetine , and citalopram on error awareness in 27 healthy participants . The error awareness task , a go/no-go response inhibition paradigm , was administered to assess the influence of monoaminergic agents on performance errors during fMRI data acquisition . A single dose of methylpheni date , but not atomoxetine or citalopram , significantly improved the ability of healthy volunteers to consciously detect performance errors . Furthermore , this behavioral effect was associated with a strengthening of activation differences in the dorsal anterior cingulate cortex and inferior parietal lobe during the methylpheni date condition for errors made with versus without awareness . Our results have implication s for the underst and ing of the neurochemical underpinnings of performance monitoring and for the pharmacological treatment of a range of disparate clinical conditions that are marked by poor awareness of errors Psychostimulants such as mixed amphetamine salts ( MAS , br and name Adderall ) are widely used for cognitive enhancement by healthy young people , yet laboratory research on effectiveness has yielded variable results . The present study assessed the effects of MAS in healthy young adults with an adequately powered double-blind cross-over placebo-controlled trial . We examined effects in 13 measures of cognitive ability including episodic memory , working memory , inhibitory control , convergent creativity , intelligence and scholastic achievement  , with the goals of determining ( 1 ) whether the drug is at least moderately enhancing ( Cohen 's d > = .5 ) to some or all cognitive abilities tested , ( 2 ) whether its effects on cognition are moderated by baseline ability or COMT genotype , and ( 3 ) whether it induces an illusory perception of cognitive enhancement . The results did not reveal enhancement of any cognitive abilities by MAS for participants in general . There was a suggestion of moderation of enhancement by baseline ability and COMT genotype in a minority of tasks , with MAS enhancing lower ability participants on word recall , embedded figures and Raven 's Progressive Matrices . Despite the lack of enhancement observed for most measures and most participants , participants nevertheless believed their performance was more enhanced by the active capsule than by placebo . We conclude that MAS has no more than small effects on cognition in healthy young adults , although users may perceive the drug as enhancing their cognition . This article is part of a Special Issue entitled ' Cognitive Enhancers ' OBJECTIVES To explore the illicit use of specific prescription stimulants among college students and add to our underst and ing of reasons ( motives ) and routes of administration associated with illicit use of these drugs . METHODS A r and om sample of 4580 college students self-administered a Web-based survey . The survey contained a variety of items pertaining to the illicit use of prescription stimulants . An extensive list of prescription stimulants was provided , and students were asked to select all the specific prescription stimulants that they had used illicitly . Items were also included to assess the motives and routes of administration associated with illicit use of prescription stimulants . RESULTS Lifetime and past-year prevalence rates for illicit use of prescription stimulants were 8.3 % ( 382 students ) and 5.9 % ( 269 students ) , respectively . Approximately three fourths ( 75.8 % ) of the 269 past-year illicit users of prescription stimulants reported using an amphetamine-dextroamphetamine combination agent ( e.g. , Adderall ) in the past year , and approximately one fourth ( 24.5 % ) reported using methylpheni date ( e.g. , Ritalin , Concerta , Meta date , Methylin ) . Past-year illicit use of prescription stimulants was more than 3 times more likely among Caucasians ( odds ratio [ OR ] 3.1 , 95 % confidence interval [ CI ] 1.5 - 6.6 ) and Hispanics ( OR 3.8 , 95 % CI 1.6 - 9.3 ) compared with African-Americans , and more than twice as likely among Caucasians ( OR 2.1 , 95 % CI 1.3 - 3.4 ) and Hispanics ( OR 2.6 , 95 % CI 1.4 - 5.1 ) compared with Asians . The most commonly reported motives for illicit use were to help with concentration ( 65.2 % ) , help study ( 59.8 % ) , and increase alertness ( 47.5 % ) . Other motives included getting high ( 31.0 % ) and experimentation ( 29.9 % ) . Nearly every illicit user ( 95.3 % ) reported oral administration , and 38.1 % reported snorting prescription stimulants . CONCLUSION Illicit use of amphetamine-dextroamphetamine is more prevalent than illicit use of methylpheni date formulations among college students Rationale The majority of studies investigating the cognitive effects of modafinil , a wake-promoting compound , demonstrate some improvements in attention . The potential of the drug to selectively benefit distinct components of attention has yet to be fully explored in healthy adults . Objective The present study was conducted to investigate modafinil ’s effect on specific cognitive tasks that tax components of attention switching . One required the rapid switching of attention between stimuli , and another contained an embedded working memory component on top of the attentional shift requirements . Additionally , prospect i ve memory was examined , which requires the interruption of an ongoing activity to retrieve and act upon a previously formed intention . Material s and methods Healthy non-smoking volunteers , matched on age , intelligence , and baseline cognitive ability , received either a capsule that contained 200 mg modafinil or placebo .  Subjective measures of mood and physiological response were taken throughout the experimental session , and the tasks were completed between 2 and 3 h post-dosing . Results Two hundred milligrams modafinil improved accuracy without a reaction time trade-off , in both conditions of the attention-shifting task , but only when re sources were most challenged . In contrast , the drug afforded no improvement in prospect i ve remembering or in the ongoing task that was interrupted . Conclusion Modafinil appears to promote rapid switching of attention in conditions that are most dem and ing , whilst it offers no benefits in a task that requires unpredictable and infrequent disengagement of attention from an ongoing task in order to act upon an alternative task Healthy human volunteers 16–82 years of age with at least 10 years of schooling were exposed to two different memory tasks . The first task involved incidental memory . The subjects were asked , as casually as possible : “ Did you watch any movie on TV 2 days ago ? And 7 days ago ? If so , do you remember the title of the movie(s ) and the name of the first two actors ( actresses ) ? ” Retention scores ( maximum = 3 : title , actor 1 , and actor 2 ) were equally high ( overall mean = 2.6 , n = 61 ) in all age groups ( 16–20 , 21–30 , 31–40 , 41–60 , and 61–82 years ) for the day 2 scores . Scores for the movie seen 7 days before decreased significantly and progressively in the three older groups in relation to age , which indicates reduced persistence of this type of memory beginning at the age of 41–50 years and becoming more extensive over the years . The other task was a formal memory procedure . Subjects were asked to study a brief text with factual information on the 1954 World Soccer Cup for 10 min . They were then exposed to 10 questions on the text 2 days and , again , 7 days later . Retention scores declined between the two tests , but in this task , the decline of persistence occurred to a similar extent in all age groups , and thus was not dependent on age . Methylpheni date ( 10 mg p.o . ) given 12 hours after acquisition markedly enhanced persistence of the two memory types . This suggests an involvement of dopaminergic processes in persistence in the late posttraining period Abstract Rationale : Altered serotonergic and dopaminergic function have been widely implicated in behavioural disorders associated with impulsivity and risk-taking . However , little research has addressed the specific cognitive consequences of changed monoaminergic function that might contribute to the production of impulsive behaviour . Objectives and methods : We compared the effects of rapid plasma tryptophan depletion , acute doses of the mixed indirect catecholamine agonist , methylpheni date ( 40 mg ) , and acute doses of the α1/α2 agonist , clonidine ( 1.5 µg/kg ) , on aspects of visual discrimination learning involving either acquisition of altered stimulus-reward associations ( i.e. updating the affective valence of exteroceptive stimuli ) or the control of attention towards relevant as opposed to irrelevant stimulus dimensions . Results : Relative to subjects who received placebo , subjects with reduced tryptophan exhibited a deficit in the ability to learn changed stimulus-reward associations , but were still able to shift an acquired attentional set away from a now-irrelevant stimulus dimension towards a newly relevant dimension . By contrast , subjects who received methylpheni date were able to learn effectively about changing stimulus-reward associations , but showed an enhanced ability to shift an attentional bias , in combination with slowed response times .  Subjects who received clonidine showed neither of these changes . Conclusions : These results suggest that reduction in central serotonin leads to altered neuromodulation of the cortical and subcortical regions ( e.g. orbitofrontal cortex , striatum and anterior temporal structures ) that mediate important aspects of associative learning whereby exteroceptive stimuli acquire altered incentive motivational value . On the other h and , facilitation of catecholamine neurotransmitters may disrupt the allocation of attention between relevant and irrelevant features of the environment , perhaps through altered modulation of the dorsolateral prefrontal cortex . The implication s of these results for underst and ing the differential neuromodulation of cognitive functions are discussed Abstract Previous studies of the effects of the psychomotor stimulant , methylpheni date , have concentrated on vigilance and reaction time tasks . In this study , the effects of methylpheni date on more complex aspects of cognition were studied using tasks from the CANTAB battery and related tests which have been shown to be sensitive to frontal lobe dysfunction . Twenty-eight young healthy men participated in a counterbalanced , double-blind , placebo-controlled study of the effects of methylpheni date .  Cognitive assessment included tests of spatial working memory , planning , verbal fluency , attentional set-shifting and sustained attention .  Methylpheni date had significant effects on performance of the tests of spatial working memory and planning but not on the attentional and fluency tests . When the drug was taken on the first test session , performance on the spatial tests was enhanced by the drug compared to placebo . However , when the drug was taken second , performance accuracy was impaired whereas response latencies were decreased . These results are consistent with a hypothesis that methylpheni date influences performance in two conflicting ways ; enhancing executive aspects of spatial function on novel tasks but impairing previously established performance . This pattern of effects is discussed within the framework of dual , interacting arousal mechanisms Models of information processing currently popular in cognitive psychology divide the reaction process into a series of discrete separable stages . The distinction between one stage and another is verified by the additive factors method ( AFM ) as defined by Sternberg ( 1969 ) . Task factors that do not interact with each other are inferred to affect different stages . The distinction between stimulus evaluation stages and response selection stages has been supported by brain event related potential ( ERP ) studies . The latency of the P300 component of the ERP is sensitive to changes in stimulus complexity but not to to changes in response complexity . The focus of this research is to determine the effects of stimulant drugs on stages of information processing using both reaction time ( RT ) and P300 latency within an AFM framework . four doses of methylpheni date ( MP ) were used in a within-subjects design to examine the effects of MP on stimulus and response processing . We found that MP speeds RT , and that this effect does not interact with the effect of stimulus complexity on RT . MP dose interacts with response complexity , the dose for optimal speeding varying with the level of complexity . The latency of P300 is increased by stimulus complexity , and not by response complexity , nor is it affected by MP . These results show that the stimulant drug acts on processes involved in response selection , rather than in stimulus evaluation . Individual differences in drug response are dose dependent , but also point to an effect on response processing Self-monitoring refers to the ability to assess accurately one 's own performance in a specific environment . The present study investigated the effects of the stimulating drugs modafinil ( 300 mg ) and d-amphetamine ( 20 mg ) on the ability to self-monitor cognitive performance during 64 h of sleep deprivation ( SD ) and sustained mental work . Two cognitive tasks were investigated : a visual ( perceptual ) judgement task and a complex mental addition task . Subjects in the placebo  condition displayed marked circadian and SD effects on cognitive task performance but their self-monitoring was substantively undisturbed by SD . Subjects performing under the influence of d-amphetamine likewise displayed highly proficient self-monitoring throughout the SD period . In contrast , modafinil had a disruptive effect on self-monitoring , inducing a reliable ' overconfidence ' effect ( i.e. an overestimation of actual cognitive performance ) , which was particularly marked 2 - 4 h post-dose . Although modafinil has proven to be a safe and effective countermeasure to the effects of extensive SD on cognitive task performance , we encourage a more comprehensive underst and ing of the relation between its subjective and performance enhancing effects before the drug is recommended as a viable fatigue countermeasure A series of five experiments was conducted to investigate the temporal aspects of human memory  consolidation of symbolic material through the administration of amphetamine . Subjects had to recall or recognise unrelated words from a previously presented list . The first experiments support the conjecture , based on animal studies , that amphetamine enhances long-term memory performance . Subsequently , enhancement is demonstrated with oral administration before learning , as well as with intramuscular injection after learning . It is shown that improved recall can not be explained solely by general arousal or attentional processes , but must be due to consolidation . By introducing different test delays we show that consolidation of symbolic material can be modulated by amphetamine during the 1st hour after learning . In a final experiment we demonstrate that the memory enhancement applies to recall as well as to recognition . The implication s of the present results are discussed in the context of recent research on LTP processes The behavioral , cognitive , and electrophysiological effect of a single dose of dextroamphetamine ( 0.5 milligram per kilogram of body weight ) or placebo was examined in 14 normal prepubertal boys ( mean age , 10 years 11 months ) in a double-blind study . When amphetamine was given , the group showed a marked decrease in motor activity and reaction time and improved performance on cognitive tests . The similarity of the response observed in normal children to that reported in children with " hyperactivity " or minimal brain dysfunction casts doubt on pathophysiological models of minimal brain dysfunction which assume that children with this syndrome have a clinical ly specific or " paradoxical " response to stimulants The study examined the effects of expectation on the subjective effects and oral self-administration of 15 mgd-amphetamine ( AMP ) and placebo in 40 volunteers who reported no prior use of stimulants other than caffeine . A balanced placebo design was used to create four groups : told Placebo/got Placebo ( P/P ) , told Placebo/got Stimulant ( P/S ) , told Stimulant/got Placebo ( S/P ) , told Stimulant/got Stimulant ( S/S ) . There were three sessions . On one session ( INFO ) , participants received a capsule containing AMP or placebo and were given information about the contents of the capsule according to the balanced placebo design . On another session ( NO INFO ) , participants received no information about the capsule 's contents and were given placebo . On the final session , participants were allowed to choose either the INFO or NO INFO capsule . Participants came to the laboratory to ingest their capsules , and then returned to their normal environments where they completed subjective effects question naires every 2 h for 8 h. Expectancies influenced the subjective effects reported during the INFO session , regardless of whether subjects actually received AMP or placebo : subjects who expected a stimulant had higher ratings of “ feel drug ” and “ like drug ” . The pharmacological effects of AMP were also evident on the INFO sessions : AMP produced its prototypic subjective effects regardless of subjects ' expectancies . Significant interactions between drug and expectancy were obtained on self-report measures of anxiety and arousal : anxiety was higher for groups who received substances that did not match their expectations ( P/S and S/P ) and arousal increased most in volunteers who expected placebo but received stimulant . Choice of drug was determined primarily by pharmacology : participants who received AMP on the INFO session usually chose that capsule , regardless of information about its identity ( P/S : 8/10 ; S/S : 9/10 ) . In contrast , participants who received placebo on the INFO session chose this capsule at chance levels , regardless of information about its identity ( S/P : 3/10 ; P/P : 6/10 ) . Thus , expectancy influenced some of the subjective effects of AMP and placebo , but the pharmacological effects of the AMP were instrumental in determining whether volunteers would self-administer the drug To assess the prevalence and motives for illicit use of  prescription stimulants  and alcohol and other drugs ( AODs ) , associated with these motives , the authors distributed a self-administered Web survey TO a r and om sample of 9,161 undergraduate college students . Of the study participants , 8.1 % reported iifetime and 5.4 % reported past-year illicit use of prescription stimulants .  The most prevalent motives given for illicit use of prescription stimulants were to ( 1 ) help with concentration , ( 2 ) increase alertness , and ( 3 ) provide a high . Although men were more likely than women were to report illicit use of prescription stimulants , the authors found no gender differences in motives . Regardless of motive , illicit use of prescription stimulants was associated with elevated rates of AOD use , and number of motives endorsed and AOD use were positively related . Students appear to be using these prescription drugs non-medically , mainly to enhance performance or get high The effects of a single oral dose of dextroamphetamine sulfate on motor activity , vigilance , learning , and mood were compared for normal and hyperactive prepubertal boys and normal college-aged men using a double-blind crossover design . Both groups of boys and men showed decreased motor activity increased vigilance , and improvement on a learning task after taking the stimulant drug . The men reported euphoria , while the boys reported only feeling " tired # or " different # after taking the stimulant . It is not clear whether this difference in effect on mood between adults and children is due to differing experience with drugs , ability to report affect , or a true pharmacologic age-related effect . While there were some quantitative differences in drug effects on motor activity and vigilance between these different groups , stimulants appear to act similarly on normal and hyperactive children and adults
target: RESULTS Modafinil appears to improve reaction time ( P ≤ 0.04 ) , logical reasoning ( P ≤ 0.05 ) and problem-solving .
  Across all three types of prescription stimulants , research shows improved attention with lack of consensus on whether these improvements are limited to simple versus complex tasks in varying youth population s. CONCLUSIONS The heterogeneity of the non-attention deficit hyperactivity disorder youth population , the variation in cognitive task characteristics and lack of replication of studies makes assessing the potential global neurocognitive benefits of stimulants among non-attention deficit hyperactivity disorder youth difficult ; however , some youth may derive benefit in specific cognitive domains
background: BACKGROUND AND AIMS Increasing prescription stimulant abuse among youth without diagnoses of attention deficit hyperactivity disorder ( ADHD ) is of concern .
  The most frequently cited motive for abuse is improved academic achievement via neurocognitive enhancement .
  Our aim in review ing the literature was to identify neurocognitive effects of prescription stimulants in non-ADHD youth .