Tavares T F, Judice-Daher D M, Bueno J L O
Departamento de Psicologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
Braz J Med Biol Res. 2019;52(7):e8303. doi: 10.1590/1414-431X20198303. Epub 2019 Jul 10.
Reinforcement omission effects (ROEs) are characterized by higher response rates after reinforcement omission than after reinforcement delivery. This pattern of behavior is interpreted in terms of motivational and attentional processes. Recent studies from our laboratory have shown that the amygdala, nucleus accumbens, and medial prefrontal cortex are involved in ROE modulation. Also, the literature has demonstrated a role of other areas such as substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA) in processes related to surprising events, such as prediction error and presentation or omission of an event (exteroceptive stimulus and reinforcement). Since these structures send projections to areas related to ROE modulation such as the amygdala, nucleus accumbens, and prefrontal cortex, the objective of the present study was to determine whether the SNc and VTA also integrate the circuit involved in ROE modulation. Rats were trained on a fixed-interval 12 s with limited-hold 6 s signaled schedule of reinforcement (Pre-lesion training). After acquisition of stable performance, the rats received bilateral neurotoxic lesions of the SNc (Experiment 1) and VTA (Experiment 2). Following postoperative recovery, the rats were submitted to two refresher sessions (Post-lesion training). Subsequently, the training was changed from a 100 to a 50% schedule of reinforcement (Post-lesion testing). In both experiments, the results showed that there was no difference in performance between sham rats and rats with bilateral lesions of the SNc or the VTA.
强化缺失效应（ROEs）的特征是强化缺失后的反应率高于强化给予后的反应率。这种行为模式是根据动机和注意力过程来解释的。我们实验室最近的研究表明，杏仁核、伏隔核和内侧前额叶皮质参与了ROE调节。此外，文献已经证明了其他区域，如黑质致密部（SNc）和腹侧被盖区（VTA）在与意外事件相关的过程中的作用，如预测误差以及事件（外部感受性刺激和强化）的呈现或缺失。由于这些结构向与ROE调节相关的区域，如杏仁核、伏隔核和前额叶皮质发送投射，本研究的目的是确定SNc和VTA是否也整合了参与ROE调节的回路。大鼠在固定间隔12秒、有限保持6秒的信号强化时间表上进行训练（损伤前训练）。在获得稳定表现后，大鼠接受SNc（实验1）和VTA（实验2）的双侧神经毒性损伤。术后恢复后，大鼠接受两次复习训练（损伤后训练）。随后，训练从100%强化时间表改为50%强化时间表（损伤后测试）。在两个实验中，结果表明，假手术大鼠与SNc或VTA双侧损伤的大鼠在表现上没有差异。
