Global and local processing of visual stimuli, functional hemispheric asymmetry of the brain and biological sex

The results of most research on the role of the two hemispheres in processing hierarchical patterns indicate a right hemisphere relative superiority in processing of global shape and a left hemisphere relative predominance in processing of local details. However, some studies suggest that hemispheric specialization can be modified by stimulus category - verbal or figural. The purpose of this research was to study hemispheric lateralization for global and local processing of visual stimuli from different categories. Furthermore we investigated whether biological sex influences the processing of complex visual patterns. Fifty men and forty eight women participated in the experiment. It was carried out using lateral presentation of letter- and figure-based hierarchical stimuli. The results of this study indicated relative right hemisphere specialization for global processing and relative left hemisphere specialization for local processing. This asymmetry was more pronounced in men. This finding is in agreement with a hypothesis that male brains are more lateralised than female brains. Stimulus category did not modify hemispheric specialization but it influenced response time and accuracy. In addition the study showed that stimulus category modifies effect of interference between elements from different levels of stimuli.