Global Versus Local Processing in the Absence of Low Spatial Frequencies

Abstract
When observers are presented with hierarchical visual stimuli that contain incongruous coarse ("global") and fine ("local") pattern attributes, the global structure interferes with local pattern processing more than local structure interferes with global pattern processing. This effect is referred to as "global precedence." The present experiments tested the hypothesis that global precedence depends on the presence of low spatial frequencies using stimuli constructed from "contrast balanced dots." Stimuli composed of contrast balanced dots are largely devoid of low-frequency content. Choice reaction time to identify either the local or global pattern information was the dependent measure. Global precedence was found only for control stimuli that contained low spatial frequencies. In the absence of low-frequency information, local precedence was obtained. These findings suggest that global precedence is heavily dependent on the low spatial frequency content of the patterns.