Student Presenter(s): Ibraheem Qureshi, Elan Adhemi, Rehel Ahmed, and Daniel Tanis
Faculty Mentor: Isaac Kurtzer
School/College: Osteopathic Medicine, Old Westbury

Research on target selection before reach initiation indicates humans have a strong preference to the least effortful reach. We conducted two studies to further explore. Both experiments utilized a start and final target placed 10cm behind and ahead of the right hand, and a 45° shoulder and 90° elbow configuration. Re-directing the moving arm involves near-maximal differences in inertial resistance towards leftward targets (more) versus rightward targets (less). In Expt. 1 (5F/7M, mean age=22.8), two target options were presented soon after movement initiation. In Expt. 2 (7F/1M, mean age=22.1), two target options were presented before movement initiation. Expt. 2 also had a “via target” between the start and end target that subjects had to reach forward then deviate laterally like the motion pattern in Expt. 1. 9 target pairs (± 1,2,3 cm) were intermingled among no-change and one-target change trials. Participants showed more bias to the less effortful option in Expt. 1 than reported in our published study: median = 65% (35 IQR) vs 52% (16 IQR), one-sided rank-sum test, p=.033. Expt. 2 tended to have more bias to the less effortful option, median = 91% ¬(37 IQR), though this didn’t significantly differ from Expt.