Abstract: Systems and methods for generating and rendering one or more images, such as in an animated image sequence, of the virtual multi-dimensional object on a display screen for testing a person's susceptibility to a Depth Inversion Illusion (“DII”). The methods also include collecting first information indicating the person's perceptual response to the DII; adjusting a strength of the DII by manipulating a texture that is mapped onto the virtual multi-dimensional object; collecting second information indicating the person's perceptual response to the DII; using the first and second information to determine differences between the person's perceptual responses to the DII and reference perception responses of a group of control subjects to the DII; and analyzing the differences to determine a severity of the person's mental illness or to assess therapeutic efficacy.