A theory of the visual system biology underlying development of spatial frequency lateralization

The spatial frequency hypothesis contends that performance differences between the hemispheres on various visuospatial tasks are attributable to lateralized processing of the spatial frequency content of visual stimuli. Hellige has proposed that such lateralization could arise during infant development from the earlier maturation of the right hemisphere combined with the increasing sensitivity of the visual system to high spatial frequencies. This proposal is intuitively appealing but lacks an explicit theory with respect to the underlying visual system biology. In this paper, we develop such a theory based on knowledge of visual system processing and development. We then translate our theory into a computational model that serves as the basis for a series of development simulations. We find that the simulations produce spatial frequency lateralization effects consistent with those observed empirically. We relate the nature of the neural asymmetry implied by our theory to empirical findings on visual pathway bias and the relative spatial frequency lateralization effect.