Harris Justin A, Kwok Dorothy W S
School of Psychology, The University of Sydney.
J Exp Psychol Anim Learn Cogn. 2018 Jan;44(1):23-35. doi: 10.1037/xan0000158.
During magazine approach conditioning, rats do not discriminate between a conditional stimulus (CS) that is consistently reinforced with food and a CS that is occasionally (partially) reinforced, as long as the CSs have the same overall reinforcement rate per second. This implies that rats are indifferent to the probability of reinforcement per trial. However, in the same rats, the per-trial reinforcement rate will affect subsequent extinction-responding extinguishes more rapidly for a CS that was consistently reinforced than for a partially reinforced CS. Here, we trained rats with consistently and partially reinforced CSs that were matched for overall reinforcement rate per second. We measured conditioned responding both during and immediately after the CSs. Differences in the per-trial probability of reinforcement did not affect the acquisition of responding during the CS but did affect subsequent extinction of that responding, and also affected the post-CS response rates during conditioning. Indeed, CSs with the same probability of reinforcement per trial evoked the same amount of post-CS responding even when they differed in overall reinforcement rate and thus evoked different amounts of responding during the CS. We conclude that reinforcement rate per second controls rats' acquisition of responding during the CS, but at the same time, rats also learn specifically about the probability of reinforcement per trial. The latter learning affects the rats' expectation of reinforcement as an outcome of the trial, which influences their ability to detect retrospectively that an opportunity for reinforcement was missed, and, in turn, drives extinction. (PsycINFO Database Record
在杂志接近条件反射训练中，只要条件刺激（CS）每秒的总体强化率相同，大鼠就不会区分持续用食物强化的条件刺激和偶尔（部分）强化的条件刺激。这意味着大鼠对每次试验的强化概率漠不关心。然而，对于相同的大鼠，每次试验的强化率会影响随后的消退——持续强化的CS比部分强化的CS的反应消退得更快。在这里，我们用每秒总体强化率匹配的持续强化和部分强化的CS训练大鼠。我们在CS期间和CS之后立即测量条件反应。每次试验强化概率的差异不影响CS期间反应的习得，但确实影响该反应随后的消退，并且还影响条件反射期间CS后的反应率。事实上，每次试验强化概率相同的CS即使在总体强化率不同从而在CS期间引发不同量的反应时，也会引发相同量的CS后反应。我们得出结论，每秒的强化率控制大鼠在CS期间反应的习得，但同时，大鼠也专门学习每次试验的强化概率。后者的学习会影响大鼠对作为试验结果的强化的期望，这会影响它们追溯检测到错过强化机会的能力，进而推动消退。（PsycINFO数据库记录）
