Allocation of processing resources between right and left spatial attention

Researches in Visual Evoked Potentials (VEPs) showed that spatial attention exerted an amplitude modulation of the attended inputs in primary visual cortex during the interval 80–200 ms following stimulus onset. VEPs data of a classical left or right visual field selective attention experiment were analyzed by the method of spatial principal component analysis (PCA) and statistical analysis. The results indicated that allocation of processing resources in humans had differences between right and left spatial attention when stimuli appeared in unattended position. Transferring attention from right to left demanded more energy than shifting attention from left to right. It implied that right-handed subjects might have an advantage in right spatial attention.