Word perception and upper-lower visual field asymmetries

Left-hemispheric lateralisation generally associates with superiority of language processing, facilitated by specialist representational and attentional influences, albeit characterised by individual differences due to handedness. In this research, we examine perceptual processing of linguistic input in left- and right-handers, and assess lateral asymmetries in the vertical dimension that is embedded within upper-lower visual fields. We use a behavioural design with presentation of bilateral stimuli (upper or lower) visual field locations during match and mismatch conditions. The data revealed that both groups were more successful in the upper than lower visual field. However, left- as compared to right-handers demonstrated increased processing in these locations, indicating beneficial effects that point to stronger perceptual responsiveness. The observations are indicative of intrinsic cross-hemispheric biases as well as acquired patterns due to perceptuo-motor experiences. In addition, hand and eye preference facilitated responses in bilateral upper visual field locations. The findings propose intricate connections between manual and attentional control with perceptual asymmetries that are steered by dedicated mechanisms. In conclusion, the data illustrate that hand and eye preference act as mediators that guide responding to visual input within the environment.