Exploring handedness and the likelihood of "switching hands" within a young adult population after practice with the non-dominant hand


Previous research has shown that those who strongly prefer one hand over the other will unconsciously select that limb to perform more unimanual tasks (Scharoun & Bryden, 2014). The purpose of the current research was to investigate the potential influence of practice on limb selection in a preferential reaching task. We hypothesized that moderate training of a simple task using only the non-preferred upper limb would influence the frequency of selecting the non-preferred limb. Participants aged 18-25 years (n=15) were asked to first complete the Waterloo Handedness Questionnaire to determine the preferred hand. Next, participants were asked to complete two trials of the Annett Pegboard Task with each hand. The task required participants to move a set of stationary pegs from one end of the board to the other as quickly as possible. Participants were then asked to complete a preferential reaching task using Fitlights. Here, five Fitlights were placed in a semicircular configuration (+-90°, +-45°, 0°) in front of the participant. Initially, participants completed 90 trials of the preferential reaching task where they were asked to tap quickly on the illuminated Fitlight with one hand. Next, participants were asked to complete 600 "training" trials, with only their non-preferred hand. After these "training" conditions, participants were asked to complete the same preferential reaching task, where differences in limb selection were compared. The Annett Pegboard Task was completed again at the conclusion of the experiment. Preliminary results indicate an increase in the frequency of unimanual tasks completed with the non-preferred hand following the training conditions. The findings will be discussed in light of practice theories of handedness.