The numerous studies on pseudoneglect have generated
inconsistent results and disagreement concerning the
underlying mechanisms. Most research supports the
hypothesis that hemispheric lateralization is the main reason
for the persistent leftward bias in spatial tasks. Findings on
the influence of reading direction, handedness and participant
age are largely contradictory. As a result of brain maturation
adults usually perform with significant leftward bias.
However, both hemispheric activation and scanning habits
exert an influence on space representation, which varies
across age groups. Preschoolers, middle school children and
adults were tested on the line and word bisection tasks and on
house-person-tree drawing tasks. The analysis of their
performance produced results consistent with an explanatory
account that the direction of the spatial bias shifts leftwards in
the course of development.