Rothkirch Marcus, Wieser Maximilian, Sterzer Philipp
Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Psychiatry and Psychotherapy, Berlin, Germany.
Bernstein Center for Computational Neuroscience, Humboldt Universität Berlin, Berlin, Germany.
PeerJ. 2021 Mar 15;9:e10875. doi: 10.7717/peerj.10875. eCollection 2021.
Human faces can convey socially relevant information in various ways. Since the early detection of such information is crucial in social contexts, socially meaningful information might also have privileged access to awareness. This is indeed suggested by previous research using faces with emotional expressions. However, the social relevance of emotional faces is confounded with their physical stimulus characteristics. Here, we sought to overcome this problem by manipulating the relevance of face stimuli through classical conditioning: Participants had to learn the association between different face exemplars and high or low amounts of positive and negative monetary outcomes. Before and after the conditioning procedure, the time these faces needed to enter awareness was probed using continuous flash suppression, a variant of binocular rivalry. While participants successfully learned the association between the face stimuli and the respective monetary outcomes, faces with a high monetary value did not enter visual awareness faster than faces with a low monetary value after conditioning, neither for rewarding nor for aversive outcomes. Our results tentatively suggest that behaviorally relevant faces do not have privileged access to awareness when the assessment of the faces' relevance is dependent on the processing of face identity, as this requires complex stimulus processing that is likely limited at pre-conscious stages.
人类的面孔能够以多种方式传达与社会相关的信息。由于在社交情境中尽早察觉此类信息至关重要,具有社会意义的信息或许也能优先进入意识层面。先前针对带有情感表情面孔的研究确实暗示了这一点。然而,带有情感的面孔所具有的社会关联性与它们的物理刺激特征相互混淆。在此,我们试图通过经典条件作用来操控面孔刺激的关联性,以克服这一问题:参与者必须学习不同面孔范例与高额或低额正负货币结果之间的关联。在条件作用程序前后,运用连续闪光抑制(双眼竞争的一种变体)来探究这些面孔进入意识所需的时间。尽管参与者成功学会了面孔刺激与各自货币结果之间的关联,但在条件作用之后,具有高货币价值的面孔进入视觉意识的速度并不比低货币价值的面孔更快,无论是对于奖励性结果还是厌恶性结果而言。我们的研究结果初步表明,当对面孔关联性的评估依赖于对面孔身份的处理时,与行为相关的面孔并不会优先进入意识,因为这需要复杂的刺激处理,而这种处理在意识前阶段可能是有限的。