La normalizzazione dell'inclinazione dell'immagine consecutiva e il ruolo della costanza di orientamento
Most of afterimage spatial characteristics such as width and shape can be referred to an environmental frame of reference. As regards the space orientation of an afterimage, it is still an open question whether such an orientation should be referred to a retinal or to an environmental frame of reference. The main aim of this work was to study the orientation of a line afterimage It is possible to demonstrate that, when an observer tilts his / her head while projecting an afterimage onto a frontoparallel projection plane, the afterimage normalizes to the environmental horizon. In fact, the amount of the afterimage tilt is statistically smaller than the amount of the head tilt. The results of the present work showed that the difference between the amount of the afterimage tilt and that of the head tilt cannot be explained by static countertorsion which corresponds only to the 10% of the head tilt. Therefore, a tentative explanation of the results is that the spatial orientation of an afterimage might be referred to an environmental frame of reference rather than to a retinal one.
