Apparent Rest
In this pattern, you see a sort of spotlight that rotates in a gray field, sequentially revealing different parts of a black circle over a white surround. This interpretation is not obvious: at the tips of the lentil-shaped region there is information suggesting that the lentil is in fact rotating. Metelli (1940) was so impressed with this lack of potential motion that he called this phenomenon "apparent rest". Apparent rest may be understood as a demonstration of the role of occlusion on motion integration. Given that the tips of the lentil are not treated as real contour terminators, but as accidental terminators revealed by the spotlight, the visual system does not enter their motion signals into the computation of the global motion percept. For an alternative interpretation of apparent rest in terms of a homogeneity principle, see Metelli (1965).


created by Fauzia Mosca and Nicola Bruno