Obstacle avoidance is a skill that humans possess in a number of movement domains, which is important for successfully acting in and upon our environment. For hand movements, obstacle avoidance is the ability to steer the hand around objects that obstruct movement toward a target. Research has determined that people are generally well able to perform these movements under a myriad of conditions: whether the nontargets are close to the hand (e.g., Mon-Williams, Tresilian, Coppard, & Carson,
2001) or next to the target (Biegstraaten, Smeets, & Brenner,
2003), large or small (Chapman & Goodale,
2008), oriented vertically or diagonally (Kritikos, Bennett, Dunai, & Castiello,
2000), close or further away in distance (e.g., Chapman & Goodale,
2008; Rice et al.,
2006), the avoidance response is ostensibly subtle and precise (Tresilian,
1998). This is reflected by the fact that the hand veers smoothly around or away from a (partially) obstructing object with a minimum distance between hand and object (Dean & Bruwer,
1994). Therefore, kinematic parameters of the movement appear to be altered to reduce the risk of collision (Hamilton & Wolpert,
2002). These parameters include the deviation of the movement (i.e., the change in trajectory of the hand relative to a move in a workspace without an obstacle present), but also movement speed, grip aperture, movement time, and reaction time. The same spatial and temporal adaptations are noticed when nontargets are not necessarily obstructing the movements of the limbs towards the target (e.g., Tipper, Howard, & Jackson,
1997; Welsh,
2011).