Spatial representation of action phrases among bidirectional readers: The effect of language environment and sentence complexity

Perceptual bias in simple visuospatial tasks, such as line bisection seen among healthy dextrals, has often been attributed to the hemispheric activation hypothesis. The often reported leftward perceptual bias was explained by an activation of the right hemisphere during visuospatial tasks. However, imposed scanning direction and stimuli saliency have also been used to explain these spatial asymmetries. One example of scanning direction is the well-trained one resulting from reading direction. Here, we present studies that target the role of reading direction on nonverbal tasks: line bisection, esthetic preference, and straight-ahead pointing by comparing left-to-right and right-to-left readers. The findings are discussed regarding the interaction between cultural factors, such as reading habits, and biological factors, such as cerebral lateralization.