Department of Psychology, The Pennsylvania State University, University Park, PA, United States.
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States.
Prog Brain Res. 2019;247:71-87. doi: 10.1016/bs.pbr.2019.03.006. Epub 2019 Apr 23.
Recently, speed of presentation of facially expressive stimuli was found to influence the processing of compound threat cues (e.g., anger/fear/gaze). For instance, greater amygdala responses were found to clear (e.g., direct gaze anger/averted gaze fear) versus ambiguous (averted gaze anger/direct gaze fear) combinations of threat cues when rapidly presented (33 and 300ms), but greater to ambiguous versus clear threat cues when presented for more sustained durations (1, 1.5, and 2s). A working hypothesis was put forth (Adams et al., 2012) that these effects were due to differential magnocellular versus parvocellular pathways contributions to the rapid versus sustained processing of threat, respectively. To test this possibility directly here, we restricted visual stream processing in the fMRI environment using facially expressive stimuli specifically designed to bias visual input exclusively to the magnocellular versus parvocellular pathways. We found that for magnocellular-biased stimuli, activations were predominantly greater to clear versus ambiguous threat-gaze pairs (on par with that previously found for rapid presentations of threat cues), whereas activations to ambiguous versus clear threat-gaze pairs were greater for parvocellular-biased stimuli (on par with that previously found for sustained presentations). We couch these findings in an adaptive dual process account of threat perception and highlight implications for other dual process models within psychology.
最近，有研究发现，面部表情刺激的呈现速度会影响复合威胁线索（如愤怒/恐惧/注视）的处理。例如，当威胁线索快速呈现（33ms 和 300ms）时，杏仁核的反应更强，而当威胁线索呈现时间更长（1s、1.5s 和 2s）时，杏仁核对模糊（回避注视的愤怒/注视的恐惧）威胁线索的反应更强，而对清晰（直接注视的愤怒/回避注视的恐惧）威胁线索的反应更弱。有一个工作假说（Adams 等人，2012）认为，这些影响是由于威胁的快速处理和持续处理分别对应于大细胞和小细胞通路的差异贡献。为了直接检验这种可能性，我们在 fMRI 环境中使用专门设计的表达面部表情的刺激物来限制视觉流处理，这些刺激物专门用于将视觉输入偏向大细胞和小细胞通路。我们发现，对于大细胞偏向刺激，清晰威胁注视对激活的影响明显大于模糊威胁注视（与之前发现的快速呈现威胁线索的结果一致），而对于小细胞偏向刺激，模糊威胁注视对激活的影响明显大于清晰威胁注视（与之前发现的持续呈现威胁线索的结果一致）。我们将这些发现置于威胁感知的自适应双过程模型中，并强调了它们对心理学中其他双过程模型的影响。
