Reference repulsion is not a perceptual illusion
Source
Cognition, 184, (2019), pp. 107-118ISSN
Publication type
Article / Letter to editor
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Organization
PI Group Predictive Brain
SW OZ DCC CO
Journal title
Cognition
Volume
vol. 184
Languages used
English (eng)
Page start
p. 107
Page end
p. 118
Subject
180 000 Predictive Brain; Action, intention, and motor controlAbstract
Perceptual decisions are often influenced by contextual factors. For instance, when engaged in a visual discrimination task against a reference boundary, subjective reports about the judged stimulus feature are biased away from the boundary - a phenomenon termed reference repulsion. Until recently, this phenomenon has been thought to reflect a perceptual illusion regarding the appearance of the stimulus, but new evidence suggests that it may rather reflect a post-perceptual decision bias. To shed light on this issue, we examined whether and how orientation judgments affect perceptual appearance. In a first experiment, we confirmed that after judging a grating stimulus against a discrimination boundary, the subsequent reproduction response was indeed repelled from the boundary. To investigate the perceptual nature of this bias, in a second experiment we measured the perceived orientation of the grating stimulus more directly, in comparison to a reference stimulus visible at the same time. Although we did observe a small repulsive bias away from the boundary, this bias was explained by random trial-by-trial fluctuations in sensory representations together with classical stimulus adaptation effects and did not reflect a systematic bias due to the discrimination judgment. Overall, the current study indicates that discrimination judgments do not elicit a perceptual illusion and points towards a post-perceptual locus of reference repulsion.
This item appears in the following Collection(s)
- Academic publications [238441]
- Donders Centre for Cognitive Neuroimaging [3824]
- Electronic publications [122508]
- Faculty of Social Sciences [29483]
- Open Access publications [97504]
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