The role of background statistics in face adaptation.

Full Abstract

Cross-adaptation is widely used to probe whether different stimuli share common neural mechanisms. For example, that adaptation to second-order stimuli usually produces little aftereffect on first-order stimuli has been interpreted as reflecting their separate processing. However, such results appear to contradict the cue-invariant responses of many visual cells. We tested the novel hypothesis that the null aftereffect arises from the large difference in the backgrounds of first- and second-order stimuli. We created second-order faces with happy and sad facial expressions specified solely by local directions of moving random dots on a static-dot background, without any luminance-defined form cues. As expected, adaptation to such a second-order face did not produce a facial-expression aftereffect on the first-order faces. However, consistent with our hypothesis, simply adding static random dots to the first-order faces to render their backgrounds more similar to that of the adapting motion face led to a significant aftereffect. This background similarity effect also occurred between different types of first-order stimuli: real-face adaptation transferred to cartoon faces only when noise with correlation statistics of real faces or natural images was added to the cartoon faces. These findings suggest the following: (1) statistical similarities between the featureless backgrounds of the adapting and test stimuli can influence aftereffects, as in contingent adaptation; (2) weak or null cross-adaptation aftereffects should be interpreted with caution; and (3) luminance- and motion-direction-defined forms, and local features and global statistics, converge in the representation of faces.

Author information

Author/s: Wu, Jianhua (J); Xu, Hong (H); Dayan, Peter (P); Qian, Ning (N);

Affiliation: Departments of Neuroscience and Physiology & Cellular Biophysics, Columbia University, New York, New York 10032, USA.

Grants: BB/E002536/1 (Agency:Biotechnology and Biological Sciences Research Council) ; EY016270 (Agency:NEI NIH HHS)

Journal and publication information

Publication Type: Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't

Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci), published in United States. (Language: eng)

Reference: 2009-Sep; vol 29 (issue 39) : pp 12035-44

Dates: Created 2009/10/01; Completed 2009/10/13;

PMID: 19793962, status: MEDLINE (last retrieval date: 10/13/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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