Visual Pattern Recognition in the Cerebral Hemispheres: The Role of Spatial Filtering

Abstract

The differences between the left and right cerebral hemispheres in terms of visual pattern recognition were examined within the context of the spatial filtering model of visual perception. On the basis of a wide range of evidence, it was hypothesized that the right hemisphere's predominant role in Gestalt perception may be related to its superiority in processing low spatial frequency information, while the left hemisphere may be more highly involved in an analysis of high frequency information contained in the visual environment. The spatial filtering capabilities of the left and right hemispheres were assessed by presenting square-wave gratings to the left and right visual fields, which project to the primary visual cortical areas of the contralateral hemispheres. 24 right-handed adult males were required to identify the orientation of each of six gratings varying in fundamental spatial frequency and level of contrast. Analyses of variance indicated that identification performance was superior over-all in the right visual field. The magnitude of the advantage of the right visual field latency was greater for the high frequency gratings, although this predicted trend did not attain significance. Results were discussed in relation to the spatial filtering theory and others concerning hemispheric differences in visual pattern recognition.