Relative weight of local and global properties depends on both the position of local elements and the saliency of global form

Love, Rouder, and Wisniewski (1999) and Ripoll and Marty (2005) showed that subjects could process global properties very quickly in a same/different task on abstract visual scenes for which the conspicuity of local and global properties had been controlled. In this new experiment, two important new factors were manipulated: saliency of the global pattern and location of local similarity. The results showed that the saliency of the global form as well as the location of local similarity determines the strength of global and local effects. Global effects continue to manifest themselves even when the extraction of the global form is difficult. Finally, the whole pattern of results suggests that local and global processing proceeds simultaneously and involves two attentional systems whose spatial characteristics are very different.