Usi e abusi della prospettiva: osservazioni sperimentali sulle reverspective di Patrick Hughes

Introduction. Patrick Hughes' paintings, called "reverspectives", consist of tridimensional structures (pyramids or prisms) painted in such a way to elicit an illusory depth percept that is the reverse of the physical depth arrangement. It has been shown that reverspectives having a simple grid of lines are more effective compared to those with a more naturalistic representation (Rogers & Gyani, 2010). Method. To investigate which kind of geometrical texture is more effective in eliciting the perspective reversal, twenty-eight observers were tested. Three independent variables were manipulated: 1) 3D structure (one or two pyramids); 2) geometrical texture (9 different textures), and 3) light direction (3 different directions). The dependent variable was the distance (observer-stimulus) in which the "switch-off" takes place. Results. The results shows that: a) our visual system prefers an "incorrect" construction that aims to rotate the foreshortened surfaces to the front parallel plane; b) the grid elicits a stronger illusion than the textures with oblique or orthogonal lines; c) the grids drown with the "incorrect" Hughes' logic are more coercive; and d) the light direction play a significant role in producing the illusion.