Murray L K, Kollins S H
Department of Psychology, Western Michigan University, USA.
J Appl Behav Anal. 2000 Winter;33(4):573-91. doi: 10.1901/jaba.2000.33-573.
The behavior of children diagnosed with attention deficit hyperactivity disorder (ADHD) has been hypothesized to be the result of decreased sensitivity to consequences compared to typical children. The present study examined sensitivity to reinforcement in 2 boys diagnosed with ADHD using the matching law to provide more precise and quantitative measurement of this construct. This experiment also evaluated the effects of methylphenidate (MPH) on sensitivity to reinforcement of children with ADHD. Subjects completed math problems to earn tokens under four different variable-interval (VI) schedules of reinforcement presented in random order under both medicated and nonmedicated conditions. Results showed that, in the medicated condition, the matching functions for both subjects resulted in higher asymptotic values, indicating an overall elevation of behavior rate under these conditions. The variance accounted for by the matching law was also higher under the medicated conditions, suggesting that their behavior more closely tracked the changing rates of reinforcement while taking MPH compared to placebo. Under medicated conditions, the reinforcing efficacy of response-contingent tokens decreased. Results are discussed with respect to quantifying behavioral changes and the extent to which the drug interacts with prevailing contingencies (i.e., schedule values) to influence behavioral variability.
与正常儿童相比，被诊断为注意力缺陷多动障碍（ADHD）的儿童的行为被认为是对后果敏感性降低的结果。本研究使用匹配法则，对2名被诊断为ADHD的男孩的强化敏感性进行了检验，以便对这一结构进行更精确和定量的测量。本实验还评估了哌甲酯（MPH）对ADHD儿童强化敏感性的影响。在用药和未用药两种条件下，受试者以随机顺序完成数学题，以在四种不同的可变间隔（VI）强化时间表下赚取代币。结果表明，在用药条件下，两名受试者的匹配函数都产生了更高的渐近值，表明在这些条件下行为率总体上有所提高。在用药条件下，匹配法则所解释的方差也更高，这表明与服用安慰剂相比，他们在服用MPH时的行为更密切地跟踪了强化率的变化。在用药条件下，反应依赖代币的强化效果降低。讨论了有关量化行为变化以及药物与主要偶然性（即时间表值）相互作用以影响行为变异性的程度的结果。
