What #theDress reveals about the role of illumination priors in color perception and color constancy.
Level 4 - case-series / case-control
Cross-sectional observational psychophysical study
PubMed 28793353 · doi:10.1167/17.9.4
What was done
Researchers evaluated whether individual variation in perceived colors of the dress photograph relates to illumination priors and chronotype. Observers completed the Morningness-Eveningness Questionnaire, matched perceived illumination and dress colors, performed an established illumination discrimination task to measure color constancy thresholds, and completed achromatic settings across varying luminance levels.
What was found
The abstract reports no exact numbers or effect sizes. Moderate correlations were observed between chronotype and illumination matches (morning types gave bluer matches than evening types) and dress body matches, but these were significant only at the 10% level. Inferred illumination chromaticity in the image explained variation in dress color matches, whereas color constancy discrimination thresholds did not relate to dress color perception. Achromatic settings varied by luminance, and color naming differed between the full photograph and isolated color matches.
Why it matters
This study shows that individual differences in inferred scene illumination drive divergent color perceptions of ambiguous images, but provides only weak evidence for the hypothesis that chronotype shapes these illumination priors.
Limits
The abstract omits sample size, participant demographics, exact correlation values, and p-values. The hypothesized link between chronotype and illumination priors failed to reach conventional statistical significance.