Rotman Research Institute, Baycrest Health Sciences, Toronto, Canada.
Department of Psychology and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, USA.
Sci Rep. 2017 Oct 12;7(1):13087. doi: 10.1038/s41598-017-13203-8.
Behavioral responses to threat are critical to survival. Several cortical and subcortical brain regions respond selectively to threat. However, the relation of these neural responses and their underlying representations to behavior is unclear. We examined the contribution of lower-order subcortical representations to behavioral responses to threat in adult humans. In Experiments 1 and 2, participants viewed pairs of images presented to the same eye or to different eyes. We observed a monocular advantage, which indicates subcortical facilitation, for ancestral threats (snakes, spiders), but not for modern threats, positive images, or neutral images. In Experiment 3, we presented pairs of snakes or neutral images into the temporal or nasal hemifield. For snakes only, we observed a temporal hemifield advantage, which indicates facilitation by the retino-tectal subcortical pathway. These results advance the current understanding of processing of threat by adult humans by revealing the characteristics of behaviors driven by a lower-order neural mechanism that is specialized for the processing of ancestral threats. The results also contribute to ongoing debates concerning the biological generality of neural mechanisms for processing of complex, emotionally-relevant stimuli by providing evidence for conservation of lower-order neural mechanisms for processing of ancestral threats across both ontogeny and phylogeny.
对威胁的行为反应对生存至关重要。几个皮质和皮质下脑区对威胁有选择性地反应。然而，这些神经反应及其潜在的表现与行为的关系尚不清楚。我们研究了较低层次的皮质下表现对成年人类对威胁的行为反应的贡献。在实验 1 和 2 中，参与者观看了一对同时呈现给同一只眼或不同眼的图像。我们观察到了一种单眼优势，这表明对于远古威胁（蛇、蜘蛛），存在皮质下促进作用，但对于现代威胁、正面图像或中性图像则没有。在实验 3 中，我们将一对蛇或中性图像呈现在颞或鼻侧视野。只有对于蛇，我们观察到了颞侧视野优势，这表明由视网膜-视束皮质下通路促进了处理。这些结果通过揭示由专门处理远古威胁的较低层次神经机制驱动的行为特征，推进了我们对成年人类对威胁处理的现有理解。这些结果还通过提供证据证明，在个体发生和系统发生中，处理远古威胁的较低层次神经机制是保守的，从而为处理复杂的、情绪相关的刺激的神经机制的生物普遍性的持续争论做出了贡献。
