Our literature review identified ANS dysfunction in individuals with ADHD , more often in the direction of hypo-arousal than hyper-arousal , particularly at rest and during tasks requiring response regulation and sustained attention .
Stimulant medications  increased ANS activity and , in some studies , reinforcers and rewards produced a similar effect , suggesting that ANS function can be modified in ADHD .
Although arousal mechanisms have frequently been found to be atypical in ADHD , these findings usually emerged from indirect behavioural measures which give only a limited underst and ing of arousal dysregulation in this condition .
Motivational incentives and methylphenidate enhance electrophysiological correlates of error monitoring in children with attention deficit/hyperactivity disorder
Background Children with attention deficit hyperactivity disorder ( ADHD ) are characterised by developmentally inappropriate levels of hyperactivity , impulsivity and /or inattention and are particularly impaired when performing tasks that require a high level of cognitive control . Methylpheni date ( MPH ) and motivational incentives may help improve cognitive control by enhancing the ability to monitor response accuracy and regulate performance accordingly . Methods Twenty-eight children with DSM-IV ADHD ( combined type ) aged 9–15 years and pairwise-matched typically developing children ( CTRL ) performed a go/no-go task in which the incentives attached to performance on no-go trials were manipulated . The ADHD group performed the task off and on their usual dose of MPH . CTRL children performed the task twice but were never medicated . EEG data were recorded simultaneously and two electrophysiological indices of error monitoring , the error-related negativity ( ERN ) and error positivity ( Pe ) were measured . Amplitudes of each ERP were compared between diagnostic groups ( CTRL , ADHD ) , medication days ( Off MPH , On MPH ) and motivational conditions ( baseline – low incentive , reward , response cost ) . Results Error rates were lower in the reward and response cost conditions compared with baseline across diagnostic groups and medication days . ERN and Pe amplitudes were significantly reduced in ADHD compared with CTRL , and were significantly enhanced by MPH . Incentives significantly increased ERN and Pe amplitudes in the ADHD group but had no effect in CTRL . The effects of incentives did not interact with the effects of MPH on either ERP . Effect sizes were computed and revealed larger effects of MPH than incentives on ERN and Pe amplitudes . Conclusions The findings reveal independent effects of motivational incentives and MPH on two electrophysiological markers of error monitoring in children with ADHD , suggesting that each may be important tools for enhancing or restoring cognitive control in these children
Our literature review identified ANS dysfunction in individuals with ADHD , more often in the direction of hypo-arousal than hyper-arousal , particularly at rest and during tasks requiring response regulation and sustained attention .
Stimulant medications  increased ANS activity and , in some studies , reinforcers and rewards produced a similar effect , suggesting that ANS function can be modified in ADHD .
Although arousal mechanisms have frequently been found to be atypical in ADHD , these findings usually emerged from indirect behavioural measures which give only a limited underst and ing of arousal dysregulation in this condition .