Hemispheric asymmetry for spatially filtered stimuli belonging to different semantic categories

The hemispheric specialization for processing visual stimuli as a function of spatial-frequency content and semantic category was investigated. Spatially filtered pictures of animals and tools were displayed to both hemifields at nine levels of spatial-frequency filtering following a coarse-to-fine design. Results showed a differential hemispheric specialization in relation to the semantic category of stimuli. Animals might be identified at low spatial frequencies (coarse information) in a similar extent in both hemifield conditions, while a hemispheric dissociation was found for tools (the increasing of levels of high-spatial frequency information was especially needed when such stimuli were presented to the left visual field /right hemisphere (RH) relative to that for right visual field/left hemisphere presentations).