Adaptation to Natural Facial Categories
Basic perceptual science; categorical judgment; adaptive measurement modeling
Citation
Webster, M. A., Kaping, D., Mizokami, Y., & Duhamel, P. (2004). Adaptation to natural facial categories. Nature, 428(6982), 557–561.
Project context
This study tested whether exposure to natural facial variation shifts category judgments for gender, ethnicity, and emotional expression.
Observers categorized faces along morphed continua to estimate where responses were equally likely between the two endpoints, under short-term adaptation and longer-term experience-related conditions.
PerceptMX technology role
PerceptMX methods supported quantitative estimation of category boundaries from forced-choice classification tasks.
The framework supported structured stimulus control, response capture, and modeling of boundary shifts across repeated-measures adaptation conditions.
Methodological contribution
Stimuli were grayscale facial images morphed into continua spanning paired categories. Category boundaries were estimated using interleaved adaptive staircases with reversal-based stopping rules.
Analyses compared boundary settings across adaptation conditions and related boundary placement to exposure variables using standard inferential tests.
Outcome or impact
Adaptation produced reliable shifts in perceptual boundaries across gender, ethnicity, and expression conditions, indicating dynamic recalibration of high-level visual categorization with exposure.
Results also supported experience-dependent differences in category boundaries associated with cultural exposure and social contact patterns.