A computer program for measuring body size distortion and body dissatisfaction.

A computer program is described that measures body size distortion and body dissatisfaction. The program is written using Visual Basic development tools and will run on any Windows 98 or more current system. The width of a static digital image of the participant can be manipulated using three separate psychophysical methods. In the method of adjustment, the participant adjusts the image wider or thinner to match his or her perceived size. The participants may also be required to adjust the image to their ideal size, with the discrepancy between perceived and ideal size being used as a measure of body dissatisfaction. In the staircase method, participants see an image that is continuously expanding or contracting. The participants change the direction of the distortion when the image matches their perceived size. In the adaptive probit estimation procedure, participants judge whether a static image is distorted too wide or too thin. Analysis of the responses permits a determination of the point of subjective equality (PSE) and the difference limen (DL) values. The DL reflects the amount of body size distortion necessary for the participant to detect the distortion 50% of the time. The PSE reflects the participant's subjective judgment of his or her body size. These two values are reflective of the sensory and nonsensory components, respectively, that contribute to body size judgments.