Walther Christian, Schweinberger Stefan R, Kovács Gyula
DFG Research Unit Person Perception, Friedrich-Schiller-University of Jena, Germany; Institute of Psychology, Friedrich-Schiller-University of Jena, Germany; Institute of Psychology, University of Regensburg, Germany.
DFG Research Unit Person Perception, Friedrich-Schiller-University of Jena, Germany; Institute of Psychology, Friedrich-Schiller-University of Jena, Germany; Department for General Psychology and Cognitive Neuroscience, Friedrich-Schiller-University of Jena, Germany.
Vision Res. 2014 Jul;100:47-55. doi: 10.1016/j.visres.2014.04.005. Epub 2014 Apr 24.
Adaptation-related aftereffects (AEs) have been found in the perception of face identity, in that perception of an ambiguous face is typically biased away from the identity of a preceding unambiguous adaptor face. In previous studies, we could show that both perceptual ambiguity and physical similarity play a role in determining perceived face identity AEs, Cortex 49 (2013) 1963-1977, Plos One 8 (2013) e70525. Here, we tested further the role of ambiguity by manipulating participants' task such that the very same target stimuli were either ambiguous or unambiguous regarding stimulus classification. We created two partially overlapping continua spanning three unfamiliar face identities each, by morphing identity A via B to C, and B via C to D. In a first session, participants were familiarised with faces A and C and asked to classify faces of the A-B-C continuum as either identity A or C in an AE paradigm. Following adaptation to A or C, we observed contrastive AEs for the ambiguous identity B, but not for the unambiguous identities A or C. In a second session, the same participants were familiarised with faces B and D, followed by tests of AEs for the B-C-D continuum now involving a B-D classification task. We again observed contrastive AEs but only for target identity C (ambiguous for the decision) and not for B or D (unambiguous). Our results suggest that perceptual ambiguity, as given by the task-context, determines whether or not AEs are induced.
在面部身份感知中发现了与适应相关的后效（AE），即对一张模棱两可的脸的感知通常会偏离先前明确的适应脸的身份。在之前的研究中，我们可以证明感知模糊性和物理相似性在确定感知到的面部身份AE中都起作用，《皮质》49（2013）1963 - 1977，《公共科学图书馆·综合》8（2013）e70525。在这里，我们通过操纵参与者的任务进一步测试了模糊性的作用，使得相同的目标刺激在刺激分类方面要么模棱两可要么明确。我们通过将身份A经由B变形为C，以及将B经由C变形为D，创建了两个部分重叠且各自跨越三个不熟悉面部身份的连续统。在第一个阶段，让参与者熟悉面孔A和C，并要求他们在一个AE范式中将A - B - C连续统中的面孔分类为身份A或C。在适应A或C之后，我们观察到了对模棱两可的身份B的对比性AE，但对明确的身份A或C没有观察到。在第二个阶段，让相同的参与者熟悉面孔B和D，随后对B - C - D连续统进行AE测试，现在涉及B - D分类任务。我们再次观察到了对比性AE，但仅针对目标身份C（对于决策模棱两可），而不是针对B或D（明确）。我们的结果表明，由任务背景所赋予的感知模糊性决定了是否会诱发AE。
