Wultz B, Sagvolden T
Department of Neurophysiology, University of Oslo, Norway.
Behav Genet. 1992 Jul;22(4):415-33. doi: 10.1007/BF01066613.
The spontaneously hypertensive rat (SHR) is hyperactive and has been proposed as an animal model of attention-deficit hyperactivity disorder (ADHD). Although ADHD in most cases is treated with central stimulants, behavior therapy has also been used, but with relatively limited success. The purpose of the present study was to investigate suppression of SHR hyperactivity by differentially reinforcing immobility (DRI) using a positive reinforcer. The DRI schedule required that the rat remain immobile in a particular part of an operant chamber, the target, in order to obtain the reinforcer. The time requirement, the DRI value, of these periods was increased progressively. The results showed that time spent on the target increased by increasing DRI value in both hyperactive and control rats. However, the total number of movements, on as well as outside the target, was higher for the hyperactive rats. The behavior grouped into two independent response components. One component consisted of immobility responses with durations less than 1 s, actually bursts of active responses; the other component consisted of immobility responses with durations more or less matching the DRI requirement. The reinforcement schedule modified the long-lasting immobility component in both groups. SHR received more reinforcers than WKY as long as the schedule did not require too long periods of immobility. However, the total number of movements on target was not reduced in SHR; on the contrary, it increased somewhat as the schedule requirements increased. If the behavior of ADHD children consists of two, or more, independent components similar to the ones observed in the present study, the present results may offer an explanation of why behavior therapy has limited success in the treatment of ADHD.
自发性高血压大鼠（SHR）活动过度，已被提议作为注意力缺陷多动障碍（ADHD）的动物模型。尽管大多数情况下ADHD用中枢兴奋剂治疗，但行为疗法也已被使用，但成功率相对有限。本研究的目的是使用正性强化物通过差异强化不动（DRI）来研究对SHR活动过度的抑制作用。DRI程序要求大鼠在操作箱的特定部分即目标区域保持不动，以便获得强化物。这些时段的时间要求即DRI值逐渐增加。结果表明，在多动大鼠和对照大鼠中，随着DRI值的增加，在目标区域停留的时间都增加了。然而，多动大鼠在目标区域内外的总运动次数更高。行为分为两个独立的反应成分。一个成分由持续时间小于1秒的不动反应组成，实际上是主动反应的爆发；另一个成分由持续时间或多或少与DRI要求匹配的不动反应组成。强化程序改变了两组中持续时间较长的不动成分。只要程序不要求过长时间的不动，SHR比WKY大鼠获得更多的强化物。然而，SHR在目标区域的总运动次数并未减少；相反，随着程序要求的增加，其有所增加。如果ADHD儿童的行为由两个或更多类似于本研究中观察到的独立成分组成，那么本研究结果可能解释了为什么行为疗法在ADHD治疗中成功率有限。
