A subcortical pathway is thought to have evolved to facilitate fear information transmission, but direct evidence for its existence in humans is lacking. In recent years, rapid, preattentive, and preconscious fear processing has been demonstrated, providing indirect support for the existence of the subcortical pathway by challenging the necessity of canonical cortical pathways in fear processing. However, direct support also requires evidence for the involvement of subcortical regions in fear processing. To address this issue, here we investigate whether fear processing reflects the characteristics of the subcortical structures in the hypothesized subcortical pathway. Using a monocular/dichoptic paradigm, Experiment 1 demonstrated a same-eye advantage for fearful but not neutral face processing, suggesting that fear processing relied on monocular neurons existing mainly in the subcortex. Experiments 2 and 3 further showed insensitivity to short-wavelength stimuli and a nasal-temporal hemifield asymmetry in fear processing, both of which were functional characteristics of the superior colliculus, a key hub of the subcortical pathway. Furthermore, all three experiments revealed a low spatial frequency selectivity of fear processing, consistent with magnocellular input via subcortical neurons. These results suggest a selective involvement of subcortical structures in fear processing, which, together with the indirect evidence for automatic fear processing, provides a more complete picture of the existence of a subcortical pathway for fear processing in humans. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

中文翻译：

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对恐惧面孔的处理表现出皮层下功能的特征。


人们认为皮层下通路的进化是为了促进恐惧信息的传递，但缺乏其在人类中存在的直接证据。近年来，快速、前注意和前意识的恐惧处理已被证明，通过挑战典型皮质通路在恐惧处理中的必要性，为皮质下通路的存在提供了间接支持。然而，直接支持还需要证据证明皮层下区域参与恐惧处理。为了解决这个问题，我们在这里研究恐惧处理是否反映了假设的皮质下通路中皮质下结构的特征。使用单眼/二视范式，实验 1 证明了恐惧但非中性面部处理的同眼优势，这表明恐惧处理依赖于主要存在于皮层下的单眼神经元。实验2和实验3进一步表明，恐惧处理过程中对短波长刺激不敏感，鼻颞半场不对称，这两者都是上丘的功能特征，上丘是皮层下通路的关键枢纽。此外，所有三个实验都揭示了恐惧处理的低空间频率选择性，与通过皮层下神经元的大细胞输入一致。这些结果表明皮层下结构选择性地参与恐惧处理，这与自动恐惧处理的间接证据一起，提供了人类恐惧处理皮层下通路存在的更完整的图景。 （PsycInfo 数据库记录 (c) 2024 APA，保留所有权利）。