Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, Victoria, Australia.
Australian Research Council Centre of Excellence for Integrative Brain Function, Australia.
Hum Brain Mapp. 2022 Aug 15;43(12):3873-3886. doi: 10.1002/hbm.25889. Epub 2022 Apr 25.
Rapidly detecting salient information in our environments is critical for survival. Visual processing in subcortical areas like the pulvinar and amygdala has been shown to facilitate unconscious processing of salient stimuli. It is unknown, however, if and how these areas might interact with cortical regions to facilitate faster conscious perception of salient stimuli. Here we investigated these neural processes using 7T functional magnetic resonance imaging (fMRI) in concert with computational modelling while participants (n = 33) engaged in a breaking continuous flash suppression paradigm (bCFS) in which fearful and neutral faces are initially suppressed from conscious perception but then eventually 'breakthrough' into awareness. Participants reported faster breakthrough times for fearful faces compared with neutral faces. Drift-diffusion modelling suggested that perceptual evidence was accumulated at a faster rate for fearful faces compared with neutral faces. For both neutral and fearful faces, faster response times were associated with greater activity in the amygdala (specifically within its subregions, including superficial, basolateral and amygdalo-striatal transition area) and the insula. Faster rates of evidence accumulation coincided with greater activity in frontoparietal regions and occipital lobe, as well as the amygdala. A lower decision-boundary correlated with activity in the insula and the posterior cingulate cortex (PCC), but not with the amygdala. Overall, our findings suggest that hastened perceptual awareness of salient stimuli recruits the amygdala and, more specifically, is driven by accelerated evidence accumulation in fronto-parietal and visual areas. In sum, we have mapped distinct neural computations that accelerate perceptual awareness of visually suppressed faces.
快速检测环境中的显著信息对于生存至关重要。已经表明，丘脑下核和杏仁核等皮质下区域的视觉处理有助于对显著刺激进行无意识处理。然而，尚不清楚这些区域是否以及如何与皮质区域相互作用，以促进对显著刺激的更快意识感知。在这里，我们使用 7T 功能磁共振成像 (fMRI) 与计算模型一起研究了这些神经过程，同时参与者 (n=33) 参与了打破连续闪光抑制范式 (bCFS)，在该范式中，恐惧和中性面孔最初被抑制在意识感知之外，但最终会“突破”到意识中。与中性面孔相比，参与者报告说恐惧面孔的突破时间更快。漂移扩散建模表明，与中性面孔相比，恐惧面孔的感知证据积累速度更快。对于中性和恐惧面孔，更快的反应时间与杏仁核（特别是其浅层、基底外侧和杏仁核纹状体过渡区）和岛叶的活动增加有关。证据积累速度的加快与额顶叶区域和枕叶以及杏仁核的活动增加相一致。较低的决策边界与岛叶和后扣带回皮层 (PCC) 的活动相关，但与杏仁核无关。总的来说，我们的发现表明，对显著刺激的感知意识加快会招募杏仁核，更具体地说，是由额顶叶和视觉区域中加速的证据积累驱动的。总之，我们已经绘制了加速对视觉抑制面孔的感知意识的不同神经计算。
