Investigation of the link between higher order cognitive functions and handedness

The study aimed to investigate the hypothesis that in high-functioning individuals the left-handedness phenotype facilitates the performance of executive-related tasks that engage the right hemisphere. The Trail-Making Test and Letter-Number Sequencing, previously indicated to engage the right hemisphere, were applied on 47 right-handers and 50 left-handers. There was a significant effect of handedness on both measures and an interaction effect of gender and handedness on the Trail-Making Test. The findings are considered to support the view that greater engagement of right-hemispheric resources facilitates the performance of higher order functions that orchestrate cognition, such as mental flexibility, inhibitory control, and working memory operations.