How thin is too thin? Evidence from visual aftereffects in body size estimation

Area of Science:

• Psychology
• Perceptual Science
• Body Image Research

Background:

• Social media often presents unrealistic body ideals, potentially leading to body dissatisfaction.
• Visual adaptation, where prolonged exposure shifts perception, is a proposed mechanism linking thin body exposure to altered body size judgments.

Purpose of the Study:

• To investigate if exposure to varying degrees of thinness in body images affects body size judgments relative to one's own body.
• To examine if individual differences in body image concerns moderate these perceptual aftereffects.

Main Methods:

• Thirty-four young women participated in a psychophysical task.
• Participants judged test bodies as thinner or fatter than themselves after adapting to either extremely thin or closer-to-self thin bodies.

Main Results:

• Stronger contrastive aftereffects were observed after exposure to extreme-thin bodies, indicated by lower points of subjective equality (PSEs).
• Adaptation to both thin body types shifted judgments, causing test bodies to be perceived as larger.
• Higher body concern correlated with larger baseline PSEs, suggesting a greater perceived own body size.

Conclusions:

• Visual adaptation plays a significant role in shaping perceptual judgments of body size.
• Individual differences in body concern influence the impact of visual adaptation on body image.
• Opponent coding may explain the mechanism, with more extreme adaptors yielding greater aftereffects.