School of Psychology, Park Place, Cardiff University, CF10 3AT, UK.
Neuroscience. 2011 Dec 29;199:205-12. doi: 10.1016/j.neuroscience.2011.09.065. Epub 2011 Oct 6.
Previous research suggests the infralimbic cortex is important in situations when there is competition between goal-directed and habitual responding. Here we used a response conflict procedure to further explore the involvement of the infralimbic cortex in this relationship. Rats received training on two instrumental biconditional discriminations, one auditory and one visual, in two distinct contexts. One discrimination was "over-trained" relative to the other, "under-trained," discrimination in the ratio 3:1. At test, animals were presented with incongruent audiovisual stimulus compounds of the training stimuli in the under-trained context. The stimulus elements of these test compounds have previously dictated different lever press responses during training. Rats receiving control infusions into the infralimbic cortex showed a significant interference effect, producing more responses to the over-trained (habitual), but context-inappropriate, stimulus element of the incongruent compound. This interference effect was abolished by inactivation of the infralimbic cortex; animals showed a reduced tendency to produce the habitual but inappropriate response compared with animals receiving control infusions. This finding provides evidence that the infralimbic cortex is involved in attenuating the influence of goal-directed behavior, for example context-appropriate responding.
先前的研究表明，在目标导向和习惯性反应之间存在竞争的情况下，下边缘皮层很重要。在这里，我们使用反应冲突程序进一步探讨了下边缘皮层在这种关系中的参与。
大鼠在两个不同的环境中接受了两个工具性双条件辨别任务的训练，一个是听觉的，一个是视觉的。一个辨别相对于另一个辨别是“过度训练”，比率为 3:1。在测试中，动物在未训练的环境中接受训练刺激的不一致视听刺激复合刺激。这些测试化合物的刺激元素在训练过程中曾决定了不同的杠杆按压反应。
接受 infralimbic 皮质内控制注射的大鼠表现出显著的干扰效应，对不一致复合刺激的过度训练（习惯性）但不合时宜的刺激元素产生更多的反应。下边缘皮层的失活消除了这种干扰效应；与接受对照注射的动物相比，动物表现出减少产生习惯性但不合适反应的趋势。
这一发现提供了证据，表明 infralimbic 皮层参与减弱目标导向行为的影响，例如适当的环境反应。
