Do the Principles of Motor Program Editing Apply to Longer Sequences of Rapid Aiming Movements? Part I

Prior work had shown that performing a shorter distance aiming movement prior to a longer distance aiming movement resulted in overshooting of the short movement and undershooting of the longer movement compared to repetition of the same movement. The main question was whether the same interference effects would be found in a three-movement sequence. Right-handed (N = 24) participants (aged 18-22) produced a sequence of two or three bimanual rapid lever reversals combining short (20°) and long (60°) movements with an intermovement interval of 2.5 s beginning with either the dominant or nondominant hand. Participants overshot the short target and undershot the long target when short and long movements alternated compared to same distance control conditions, but the effects were greater for the nondominant hand. Overall, the experiment demonstrated that parameter value switching was a major source of spatial inaccuracy in sequential aiming movements