Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
Neuroscience. 2021 Sep 1;471:72-79. doi: 10.1016/j.neuroscience.2021.07.019. Epub 2021 Jul 28.
Recent evidence raised the importance of the cerebellum in emotional processes, with specific regard to negative emotions. However, its role in the processing of face emotional expressions is still unknown. This study was aimed at assessing whether face emotional expressions influence the cerebellar learning processes, using the delay eyeblink classical conditioning (EBCC) as a model. Visual stimuli composed of faces expressing happy, sad and neutral emotions were used as conditioning stimulus in forty healthy subjects to modulate the cerebellum-brainstem pathway underlying the EBCC. The same stimuli were used to explore their effects on the blink reflex (BR) and its recovery cycle (BRRC) and on the cerebellar-brain inhibition (CBI). Data analysis revealed that the learning component of the EBCC was significantly reduced following the passive view of sad faces, while the extinction phase was modulated by both sad and happy faces. By contrast, BR, BRRC and CBI were not significantly affected by the view of emotional face expressions. The present study provides first evidence that the passive viewing of faces displaying emotional expressions, are processed by the cerebellum, with no apparent involvement of the brainstem and the cerebello-cortical connection. In particular, the view of sad faces, reduces the excitability of the cerebellar circuit underlying the learning phase of the EBCC. Differently, the extinction phase was shortened by both happy and sad faces, suggesting that different neural bases underlie learning and extinction of emotions expressed by faces.
最近的证据表明小脑在情绪过程中很重要，尤其是在处理负面情绪方面。然而，其对面部情绪表达的处理作用仍不清楚。本研究旨在评估面部情绪表达是否会影响小脑的学习过程，使用延迟性眨眼经典条件反射（EBCC）作为模型。使用表达快乐、悲伤和中性情绪的人脸视觉刺激作为条件刺激，调节 EBCC 所涉及的小脑-脑干通路，该研究共纳入了 40 名健康受试者。同样的刺激也被用于探索它们对眨眼反射（BR）及其恢复周期（BRRC）以及小脑-脑抑制（CBI）的影响。数据分析显示，在被动观看悲伤面孔后，EBCC 的学习成分显著减少，而悲伤和快乐面孔都能调节消退阶段。相比之下，BR、BRRC 和 CBI 不受情绪面孔观看的影响。本研究首次提供了证据表明，面部表情的被动观看会被小脑处理，而脑干和小脑-皮质连接没有明显参与。具体来说，悲伤面孔的观看会降低 EBCC 学习阶段所涉及的小脑回路的兴奋性。相反，快乐和悲伤面孔都缩短了消退阶段，这表明不同的神经基础参与了面部表达的情绪学习和消退。
