Decision-dependent aftereffects for faces.
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.
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. Electronic address: christian.walther@uni-jena.de.
Christian
C
Walther
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.
Stefan R
SR
Schweinberger
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; Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary.
Gyula
G
Kovács
D000328:Adult; D000704:Analysis of Variance; D003657:Decision Making / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology*; D005145:Face; D005260:Female; D005366:Figural Aftereffect; D006801:Humans; D008297:Male; D009473:Neuronal Plasticity; D010775:Photic Stimulation / Q000379:methods; D021641:Recognition, Psychology; D055815:Young Adult
Adaptation; Face perception; Identity; Plasticity