Representational momentum reveals visual anticipation differences in the upper and lower visual fields.

Abstract

Recent empirical research has revealed differences in functional capacity between the upper and lower visual fields (VFs), with the lower VF exhibiting superiority in visual perception skills. Similarly, functional differences between the left and right hemispheres elicit a predominance for visuospatial processing in the left visual field (left VF). Both anatomical as well as evolutionary arguments have been adopted in accounting for these variations in function. Preceding upper and lower VF research has typically investigated either static stimulus perception or the visual processing of upper limb action. The aim of the current research was to investigate whether the lower VF benefits associated with limb control transcend to visual anticipation (the perception of motion). Methods were based on Khan and Lawrence (Exp Brain Res 164:395-398, 2005), who investigated upper/lower VF differences in visuomotor control, but utilising a representational momentum paradigm to isolate perceptual processes. Thirty-two participants were randomised into either a left or right VF group and completed a perceptual computer-based task in the upper and lower VF, where they were required to judge the final position of a moving object before it disappeared. Two aspects of the distributions of same responses were then analysed; the central tendency (weighted means) and the variability. Results revealed that in the left VF, weighted means for the lower VF were significantly greater than for the upper VF [t(14)=2.242, p=0.042]. In both left and right VFs, variability was greater in the upper compared to lower VF. This provides new findings regarding visual processes in the different visual fields. While visual search and large scene perception has been found to be superior in the upper VF, here we find that visual anticipation, like target-directed visuomotor skill, is superior in the lower VF.