Reed Phil
Department of Psychology, University College London, United Kingdom.
J Exp Anal Behav. 2003 May;79(3):367-82. doi: 10.1901/jeab.2003.79-367.
Four experiments examined the effect on rats' response rate of presenting a brief (500 ms) stimulus simultaneously with the delivery of food on fixed-interval (FI) schedules. In Experiment 1, reinforcement signals that were spatially diffuse (both tones and lights) elevated rates of responding, but responding was attenuated by localized visual stimuli. The remaining experiments examined the signal-induced potentiation of responding. In Experiment 2, a tone reinforcement signal potentiated response rates on an FI schedule, but attenuated response rates on a variable-interval (VI) schedule. This difference was obtained even though the overall rate of responding was equated on the two schedules before the introduction of the signal. Signal-induced potentiation of responding occurred over a range of FI values employed in Experiment 3. In Experiment 4, presenting a reinforcement signal when high local rates of response had occurred immediately before reinforcement resulted in potentiated rates of responding on an FI schedule. The opposite effect on response rate occurred when the reinforcement signal followed only low local rates of response. These results indicate that a variety of factors influence the effects of a reinforcement signal. They imply, however, that the local rate of response at the time of reinforcement is a key factor in establishing the nature of the signaling effect.
四项实验研究了在固定间隔（FI）时间表上，与食物投递同时呈现短暂（500毫秒）刺激对大鼠反应率的影响。在实验1中，空间扩散的强化信号（音调与灯光）提高了反应率，但局部视觉刺激会减弱反应。其余实验研究了信号诱导的反应增强。在实验2中，音调强化信号在FI时间表上增强了反应率，但在可变间隔（VI）时间表上减弱了反应率。即使在引入信号之前，两个时间表上的总体反应率相等，仍获得了这种差异。在实验3采用的一系列FI值范围内，出现了信号诱导的反应增强。在实验4中，在强化之前紧接着出现高局部反应率时呈现强化信号，导致在FI时间表上反应率增强。当强化信号仅跟随低局部反应率时，对反应率产生相反的影响。这些结果表明，多种因素影响强化信号的效果。然而，它们意味着强化时的局部反应率是确定信号效果性质的关键因素。
