Research Institute for Psychological Science (IPSY), UCLouvain, Louvain-la-Neuve, Belgium.
Department of Brain and Cognition, Laboratory of Experimental Psychology, KU Leuven, Leuven, Belgium.
PLoS One. 2023 May 2;18(5):e0285255. doi: 10.1371/journal.pone.0285255. eCollection 2023.
Contextual modulations at primary stages of visual processing depend on the strength of local input. Contextual modulations at high-level stages of (face) processing show a similar dependence to local input strength. Namely, the discriminability of a facial feature determines the amount of influence of the face context on that feature. How high-level contextual modulations emerge from primary mechanisms is unclear due to the scarcity of empirical research systematically addressing the functional link between the two. We tested (62) young adults' ability to process local input independent of the context using contrast detection and (upright and inverted) morphed facial feature matching tasks. We first investigated contextual modulation magnitudes across tasks to address their shared variance. A second analysis focused on the profile of performance across contextual conditions. In upright eye matching and contrast detection tasks, contextual modulations only correlated at the level of their profile (averaged Fisher-Z transformed r = 1.18, BF10 > 100), but not magnitude (r = .15, BF10 = .61), suggesting the functional independence but similar working principles of the mechanisms involved. Both the profile (averaged Fisher-Z transformed r = .32, BF10 = 9.7) and magnitude (r = .28, BF10 = 4.58) of the contextual modulations correlated between inverted eye matching and contrast detection tasks. Our results suggest that non-face-specialized high-level contextual mechanisms (inverted faces) work in connection to primary contextual mechanisms, but that the engagement of face-specialized mechanisms for upright faces obscures this connection. Such combined study of low- and high-level contextual modulations sheds new light on the functional relationship between different levels of the visual processing hierarchy, and thus on its functional organization.
在视觉处理的初级阶段，上下文调制取决于局部输入的强度。（面部）处理的高级阶段的上下文调制表现出与局部输入强度相似的依赖性。即，面部特征的可辨别性决定了面部上下文对该特征的影响程度。由于缺乏系统地解决两者之间功能联系的经验研究，因此由于缺乏经验研究，高级上下文调制如何从主要机制中出现尚不清楚。我们使用对比检测和（直立和倒置）变形面部特征匹配任务测试了（62）名年轻人独立于上下文处理局部输入的能力。我们首先调查了跨任务的上下文调制幅度，以解决它们的共同方差。第二项分析侧重于跨上下文条件的性能分布。在直立眼睛匹配和对比检测任务中，上下文调制仅在其分布（平均 Fisher-Z 转换 r = 1.18，BF10 > 100）上相关，而不是幅度（r =.15，BF10 =.61），这表明所涉及机制的功能独立性但相似的工作原理。在倒置眼睛匹配和对比检测任务中，上下文调制的分布（平均 Fisher-Z 转换 r =.32，BF10 = 9.7）和幅度（r =.28，BF10 = 4.58）都相关。我们的结果表明，非面部专业化的高级上下文机制（倒置面孔）与初级上下文机制相连，但用于直立面孔的专业化机制的参与掩盖了这种联系。这种对低水平和高水平上下文调制的综合研究为视觉处理层次结构的不同层次之间的功能关系提供了新的认识，从而为其功能组织提供了新的认识。
