Frank R A, Williams H P
Pharmacol Biochem Behav. 1985 Apr;22(4):527-30. doi: 10.1016/0091-3057(85)90269-2.
Self-stimulation thresholds obtained from rate/intensity functions have often been used to measure brain stimulation reward (BSR) under the assumption that these indices are not contaminated by performance factors. However, very few studies have explicitly examined the effect of performance variables on thresholds. The present experiment examined the joint effects of response effort and current intensity on train duration thresholds. Three levels of stimulation current and lever weightings were factorially combined and train duration thresholds (defined as 50% of maximum response rates) were determined for each condition. It was discovered that changes in both current intensity and response effort produced shifts in thresholds, and that these shifts were of approximately equal magnitude. It was concluded that caution must be exercised when interpreting self-stimulation threshold data since, at least under some conditions, both reward (i.e., train duration) and performance (i.e., effort) manipulations produced similar shifts in self-stimulation response functions.
从频率/强度函数获得的自我刺激阈值常被用于测量脑刺激奖赏（BSR），其假设是这些指标不受行为因素的影响。然而，很少有研究明确考察行为变量对阈值的影响。本实验考察了反应努力和电流强度对训练时长阈值的联合效应。将三个水平的刺激电流和杠杆重量进行析因组合，并针对每种条件确定训练时长阈值（定义为最大反应率的50%）。研究发现，电流强度和反应努力的变化都会导致阈值的偏移，且这些偏移的幅度大致相等。得出的结论是，在解释自我刺激阈值数据时必须谨慎，因为至少在某些条件下，奖赏（即训练时长）和行为（即努力）操作都会使自我刺激反应函数产生类似的偏移。
