Pierce-Messick Zachary J, Corbit Laura H
Department of Psychology, The University of Toronto, 100 St. George Street, Toronto, ON, M5S 3G3, Canada.
Sci Rep. 2024 Dec 5;14(1):30303. doi: 10.1038/s41598-024-81309-x.
Two experiments in rats examined how training where a stimulus signaled when to respond for reward, conditions that should favour S-R learning, might lead to habitual control of behaviour. Experiment 1 investigated how animals trained with a stimulus preceding lever insertion would impact learning relative to a group that was self-paced and could control lever insertion with a second, distinct response. Rats were then tested for sensitivity to outcome devaluation to distinguish between goal-directed and habitual control. We found that free-operant, self-paced conditions promoted goal-directed control while signaling trials with a stimulus promoted habitual control evidenced as insensitivity to outcome devaluation. Experiment 2 assessed whether the stimulus-outcome association is important for driving habitual responding when training occurs with a traditional discriminative stimulus. A comparison group was trained under free-operant conditions and experienced the same stimulus presented alongside the earned reward. Following devaluation, animals trained under discriminated-operant conditions had reduced goal-directed control, but only after extended training. The free-operant group remained goal-directed, even after extended training, and their performance was not altered by stimulus presentations, suggesting effects of a stimulus-outcome association were unlikely to account for the deficit in the discriminative stimulus group. These results extend understanding of how stimuli present during instrumental training promote the development of habitual control.
当有刺激信号提示何时做出反应以获取奖励时，这种理应有利于刺激-反应（S-R）学习的条件，是如何导致行为的习惯性控制的。实验1探究了与自行控制节奏且能用另一种不同反应来控制杠杆插入的组相比，用在杠杆插入前呈现刺激的方式进行训练的动物会如何影响学习。然后对大鼠进行结果贬值敏感性测试，以区分目标导向型控制和习惯性控制。我们发现，自由操作、自行控制节奏的条件促进了目标导向型控制，而用刺激信号进行的试验则促进了习惯性控制，表现为对结果贬值不敏感。实验2评估了在使用传统辨别性刺激进行训练时，刺激-结果关联对于驱动习惯性反应是否重要。一个对照组在自由操作条件下进行训练，并在获得奖励时同时经历相同的刺激。贬值后，在辨别操作条件下训练的动物的目标导向型控制有所降低，但这仅在长时间训练后才出现。即使经过长时间训练，自由操作组仍保持目标导向型，并且它们的表现不会因刺激呈现而改变，这表明刺激-结果关联的影响不太可能解释辨别性刺激组中的缺陷。这些结果扩展了我们对工具性训练期间呈现的刺激如何促进习惯性控制发展的理解。
