Luman Marjolein, Papanikolau Alky, Oosterlaan Jaap
From the *Department of Clinical Neuropsychology, VU University Amsterdam, Amsterdam; and †De Bascule, Academic Centre for Child and Adolescence Psychiatry, Duivendrecht, The Netherlands.
J Clin Psychopharmacol. 2015 Aug;35(4):414-21. doi: 10.1097/JCP.0000000000000349.
Temporal information processing and reward sensitivity are neurocognitive impairments key to attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to examine the unique and combined impact of reinforcement and methylphenidate (MPH) on temporal information processing in children with ADHD. We predicted that both monetary reinforcement and MPH would ameliorate temporal information processing deficits in ADHD, and we expected that the combined effect of reinforcement and MPH would be most beneficial. Forty children (23 with ADHD and 27 typical controls, aged 8-12 y) performed a time production task under 3 conditions: reward, response cost, and feedback only. Children with ADHD also performed the task (in random order) with placebo, a low, a medium, and a high dose of MPH. Dependent variables were time production accuracy and variability. At baseline, children with ADHD displayed poor internal clock functioning compared with controls, as reflected by greater underestimations of the 1-second interval, and they showed poor motor output as reflected by increased timing variability. Reward and response cost improved motor output (timing variability), with similar effects for both groups. Methylphenidate increased performance (timing variability) compared with placebo, with a higher dose showing greater effects. Effect sizes of reinforcement and medication were medium to large. Contrary to expectations, MPH did not add to the reinforcement effect. The results of this study confirm the value of reward and response cost being similar to that of MPH to optimize (timing) performance of children with ADHD.
时间信息处理和奖励敏感性是注意力缺陷多动障碍（ADHD）的关键神经认知障碍。本研究的目的是检验强化和哌甲酯（MPH）对ADHD儿童时间信息处理的独特及联合影响。我们预测金钱强化和MPH都会改善ADHD儿童的时间信息处理缺陷，并且我们预期强化和MPH的联合效果将最为有益。40名儿童（23名ADHD儿童和27名正常对照儿童，年龄8 - 12岁）在三种条件下进行时间生成任务：奖励、反应代价和仅反馈。ADHD儿童还在服用安慰剂、低剂量、中剂量和高剂量MPH的情况下（随机顺序）完成任务。因变量为时间生成准确性和变异性。在基线时，与对照组相比，ADHD儿童表现出较差的内部时钟功能，这表现为对1秒间隔的更大低估，并且他们的运动输出较差，表现为时间变异性增加。奖励和反应代价改善了运动输出（时间变异性），两组效果相似。与安慰剂相比，MPH提高了表现（时间变异性），高剂量显示出更大的效果。强化和药物治疗的效应大小为中等至较大。与预期相反，MPH并未增强强化效果。本研究结果证实了奖励和反应代价对于优化ADHD儿童（时间）表现的价值与MPH相似。
