 Treisman’s proposed solution exploits the fact that spatial representations are ubiquitous, and the idea that there is only one thing to be seen in any one place at any one time. If the centre for detecting colours detects red at place one and green at place two, and if the centre for detecting shape detects a tomato shape at place one and an apple shape at place two, then, given the principle that there is a maximum of one visible object per place per time, the binding problem can be solved. Treisman therefore proposes that we achieve a correctly bound representation by moving a variously sized ‘window’ from one location in the perceptual scene to another. This window blocks out the information from all but a single location, and all the features found at that location can then be ‘bound’ as being features of the same object. The area covered by the window within which features are bound is taken to correspond to the region to which attention is being paid.