Abstract:  Color constancy is an important feature of human color vision, helping to stabilize perception in environments with dynamic illumination conditions. Curious side effects of color constancy are well-known from images such as #thedress in which observers disagree with respect to perceived colors or images inducing “illusory” colors through illumination cues. Such effects have made abundantly clear that color vision is fundamentally an inferential process depending on both the context and the observer.

Here, two projects are presented which address key unknowns of color inference. The first project aims at mass-testing color inference through the website color-test.org to better understand intra- and interindividual differences in color inference. Initial results (n=500) show, among others, that with increasing age color inference is less influenced by illumination cues, suggesting that certain aspects of color constancy are unlearned rather than learned over the lifespan.
The second project (n=70) uses fMRI and multivoxel pattern analysis to address the following question: at which point of the visual cortical processing does color information transition from colorimetric color to perceived color? By training a classifier on colorimetric („true“) colors and testing on perceived (“illusory”) colors we find inverse gradients for colorimetric and perceived colors. While information about colorimetric colors is highest in V1 and deteriorates along the visual hierarchy, information about perceived colors increases from V1 onward, peaking in V3 and V4.

Webex-Link: https://fu-berlin.webex.com/fu-berlin-en/j.php?MTID=m6e999eb03e323a27f3b265bdb7a714e4