cSCAN Rounds

Visual adaptation as a potential mechanism for for the development of body size misperception

A large and growing segment of society misperceives the size of their bodies. Body size overestimation is associated with body dissatisfaction, depression, and increased risk of eating disorders, particularly in young women, while underestimation is associated with muscle dysmorphia, especially in young men, and reduced motivation to lose weight in obese people. Body size misperception is often attributed to exposure to idealised thin female and muscular male bodies in the media or, in the case of obese people who underestimate their body size, to being surrounded by overweight and obese bodies as societal levels of obesity continue to rise. Mechanisms linking this exposure to extreme bodies and the development of body size misperception are not well elucidated. Recently, we have proposed visual adaptation as a potential mechanism. This phenomenon, in which prolonged exposure to a stimulus (such as downward motion) results in adaptation of the associated neurons such that subsequently viewed stimuli (such as a static object) appear the opposite of the adapting stimulus (appear to move upward), appears repeatedly in the visual system. I will discuss research in which we examine visual adaptation in body size and shape, and the potential of this mechanism to explain body size misperception.