Which Factors Affect Hand Selection in Adults? Combined Effects of Ocular Dominance, Task Demand and Object Location

Eighty-five right-handed subjects (39 female and 46 male, 47 being right-eye dominant and 38 being left-eye dominant) were tested on three tasks of different levels of difficulty, performed in five locations. In the current study, participants were required to pick up the tool, pick up and pantomime how to use it and pick up and actual use on the materials provided. Our goal was to evaluate how the effect of object location interacts with task difficulty on adult hand selection. We also tried to evaluate the effect of eye dominance as a biological factor on hand selection. The result showed that the frequency of preferred hand reaches was greater for pantomime and real use than the pick up condition. This effect was mediated by the position of the object in hemispace, with more right hand reaches occurring for the use and pantomime task than the pick up task. The result also revealed that there is no difference between frequency of preferred hand reaches in left- and right-eye dominant. Based on results of this study, it can be suggested that limb selection depends on task and environmental constraints, rather than a biological factor like eye dominance.