Goal-directed and habitual actions are clearly defined by their associative relations. Whereas goal-directed control can be confirmed via tests of outcome devaluation and contingency-degradation sensitivity, a comparable criterion for positively detecting habits has not been established. To confirm habitual responding, a test of control by the stimulus–response association is required while also ruling out goal-directed control. Here we describe an approach to developing such a test in rats using two discriminative stimuli that set the occasion for two different responses that then earn the same outcome. Performance was insensitive to outcome devaluation and showed stimulus–response specificity, indicative of stimulus-controlled behavior. The reliance of stimulus–response associations was further supported by a lack of sensitivity during the single extinction test session used here. These results demonstrate that two concurrently trained responses can come under habitual control when they share a common outcome. By reducing the ability of one stimulus to signal its corresponding response–outcome association, we found evidence for goal-directed control that can be dissociated from habits. Overall, these experiments provide evidence that tests assessing specific stimulus–response associations can be used to investigate habits.

中文翻译：

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习惯的刺激控制：双重响应任务中刺激特异性和贬值不敏感性的证据

目标导向的行为和习惯性的行为是由它们的关联关系明确定义的。虽然目标导向的控制可以通过结果贬值和意外降级敏感性测试来确认，但尚未建立积极检测习惯的可比标准。为了确认习惯性反应，需要通过刺激-反应关联进行控制测试，同时排除目标导向控制。在这里，我们描述了一种在大鼠中使用两种辨别刺激进行此类测试的方法，这两种刺激为两种不同的反应创造了机会，然后获得相同的结果。表现对结果贬值不敏感，并表现出刺激-反应特异性，表明刺激控制的行为。此处使用的单次消光测试期间缺乏敏感性进一步支持了刺激-反应关联的依赖性。这些结果表明，当两个同时训练的反应具有共同的结果时，它们可以受到习惯性控制。通过降低一种刺激发出相应反应-结果关联信号的能力，我们发现了可以与习惯分离的目标导向控制的证据。总的来说，这些实验提供的证据表明，评估特定刺激-反应关联的测试可用于调查习惯。