Flagel Shelly B, Robinson Terry E
Department of Psychiatry, University of Michigan, Ann Arbor.
Department of Psychology, University of Michigan, Ann Arbor.
Curr Opin Behav Sci. 2017 Feb;13:178-185. doi: 10.1016/j.cobeha.2016.12.004. Epub 2017 Jan 5.
Cues in the environment can guide behavior in adaptive ways, leading one towards valuable resources such as food, water, or a potential mate. However, cues in the environment may also serve as powerful motivators that lead to maladaptive patterns of behavior, such as addiction. Importantly, and central to this article, there is considerable individual variation in the extent to which reward cues gain motivational control over behavior. Here we describe an animal model that captures this individual variation, allowing us to better understand the psychological and neurobiological processes that contribute to cue-evoked behaviors. When a discrete cue is paired with a food reward in a Pavlovian manner it acquires greater control over motivated behavior in some rats ("sign-trackers, STs) than in others ("goal-trackers", GTs). We review studies that have exploited this animal model to parse the neurobiological mechanisms involved in learning associations between stimuli vs. those involved in attributing incentive salience to those same stimuli. The latter seems to be dependent on dopamine and subcortical circuits, whereas the former may engage more cortical "top-down" mechanisms.
环境中的线索能够以适应性方式引导行为，使人趋向于食物、水或潜在配偶等有价值的资源。然而，环境中的线索也可能成为强大的诱因，导致诸如成瘾等适应不良的行为模式。重要的是，也是本文的核心，奖励线索对行为获得动机控制的程度存在相当大的个体差异。在这里，我们描述一种动物模型，它能够捕捉这种个体差异，使我们更好地理解促成线索诱发行为的心理和神经生物学过程。当一个离散线索以巴甫洛夫方式与食物奖励配对时，它对某些大鼠（“信号追踪者”，STs）的动机行为的控制要比对其他大鼠（“目标追踪者”，GTs）的控制更强。我们回顾了利用这种动物模型来剖析学习刺激之间关联所涉及的神经生物学机制与将激励显著性赋予相同刺激所涉及的神经生物学机制的研究。后者似乎依赖于多巴胺和皮层下回路，而前者可能更多地涉及皮层“自上而下”的机制。
