Unseen Fearful Faces Influence Face Encoding: Evidence from ERPs in Hemianopic Patients
Unseen Fearful Faces Influence Face Encoding: Evidence from ERPs in Hemianopic Patients
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DOI：
10.1162/jocn_a_00671
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发表时间：
2014-11-01
影响因子：
3.2
通讯作者：
Ladavas, Elisabetta
中科院分区：
文献类型：
--
作者：
Cecere, Roberto;Bertini, Caterina;Ladavas, Elisabetta
视觉威胁相关信号不仅通过皮质膝状体-纹状体通路到达杏仁核，而且还通过皮质下丘-枕-杏仁核通路进行处理，该通路可能介导恐惧刺激的内隐处理。事实上，当在他们的盲视野中同时呈现看不见的恐惧面孔时，已经显示膝状体-纹状体通路单侧损伤的偏盲患者对在他们的完整视野中看到的快乐面孔反应更快[Bertini，C.，Cecere河，& Ladavas，E.我瞎了，但我看到了恐惧。Cortex，49，985-993，2013]。这种行为促进在看不见的恐惧的存在下可能反映了增强的有意识地感知的面孔，因为早期激活的皮层下通路的内隐恐惧知觉，这可能会导致调制的皮层活动。为了验证这一假设，我们研究了ERP引起的恐惧和快乐的面孔提出了完整的视野的右侧和左侧偏盲患者，而恐惧，快乐，或中性的面孔同时提出了在他们的盲场。结果表明，当右侧偏盲患者的盲视野中同时出现一个看不见的恐惧面孔时，由所看到的快乐面孔引起的N170的振幅选择性增加。这些结果表明，当膝状体-纹状体视觉通路受损时，威胁信号的快速和内隐加工可以增强面部编码。值得注意的是，N170调制仅在左半球受损的患者中观察到，这支持了这样的假设，即恐惧信号的隐式皮层下处理只有在右半球完好无损时才能影响面部编码。
Visual threat-related signals are not only processed via a cortical geniculo-striatal pathway to the amygdala but also via a subcortical colliculo-pulvinar-amygdala pathway, which presumably mediates implicit processing of fearful stimuli. Indeed, hemianopic patients with unilateral damage to the geniculo-striatal pathway have been shown to respond faster to seen happy faces in their intact visual field when unseen fearful faces were concurrently presented in their blind field [Bertini, C., Cecere, R., & Ladavas, E. I am blind, but I see fear. Cortex, 49, 985-993, 2013]. This behavioral facilitation in the presence of unseen fear might reflect enhanced processing of consciously perceived faces because of early activation of the subcortical pathway for implicit fear perception, which possibly leads to a modulation of cortical activity. To test this hypothesis, we examined ERPs elicited by fearful and happy faces presented to the intact visual field of right and left hemianopic patients, whereas fearful, happy, or neutral faces were concurrently presented in their blind field. Results showed that the amplitude of the N170 elicited by seen happy faces was selectively increased when an unseen fearful face was concurrently presented in the blind field of right hemianopic patients. These results suggest that when the geniculo-striate visual pathway is lesioned, the rapid and implicit processing of threat signals can enhance facial encoding. Notably, the N170 modulation was only observed in left-lesioned patients, favoring the hypothesis that implicit subcortical processing of fearful signals can influence face encoding only when the right hemisphere is intact.