Tran-Tu-Yen Delphine A S, Marchand Alain R, Pape Jean-Rémi, Di Scala Georges, Coutureau Etienne
CNRS, Centre de Neurosciences Intégratives et Cognitives, UMR 5228, Talence, France.
Eur J Neurosci. 2009 Aug;30(3):464-71. doi: 10.1111/j.1460-9568.2009.06834.x. Epub 2009 Jul 15.
Lesion studies show that goal-directed actions mediated by action-outcome (A-O) associations and habits mediated by stimulus-response (S-R) associations can be dissociated during instrumental training, with the prelimbic region of the medial prefrontal cortex being involved in the former and the infralimbic region in the latter. The present work further investigates the role of the prelimbic region in acquisition vs. expression of goal-directed instrumental behaviour, using reversible neuronal inactivation and outcome devaluation procedures. In a first experiment, inactivating the prelimbic cortex at the time of testing did not alter the sensitivity to devaluation, indicating that this region was not essential for the expression of A-O associations. In a second experiment, the prelimbic cortex was inactivated throughout the training phase. At the time of testing the performance was insensitive to devaluation, indicating that the acquired response was not goal-directed but mediated by an S-R association. These data challenge the view that the habit system replaces the goal-directed system as training progresses. They show that the prelimbic cortex plays a transient but crucial role in the acquisition of goal-directed responding and that the A-O and S-R systems can operate in a competitive fashion early in training.
损伤研究表明，在工具性训练过程中，由动作-结果（A-O）关联介导的目标导向行为和由刺激-反应（S-R）关联介导的习惯是可以分离的，内侧前额叶皮质的前边缘区域参与前者，而腹内侧前额叶皮质的下边缘区域参与后者。本研究进一步使用可逆性神经元失活和结果贬值程序，研究前边缘区域在目标导向工具性行为的习得与表现中的作用。在第一个实验中，在测试时使前边缘皮质失活并不会改变对贬值的敏感性，这表明该区域对于A-O关联的表现并非必不可少。在第二个实验中，在前边缘皮质在整个训练阶段均被失活。在测试时，表现对贬值不敏感，这表明习得的反应不是目标导向的，而是由S-R关联介导的。这些数据挑战了随着训练的进行习惯系统会取代目标导向系统的观点。它们表明，前边缘皮质在目标导向反应的习得中起着短暂但关键的作用，并且A-O和S-R系统在训练早期可以以竞争方式运作。
