Related Experiment Videos
Impact forces cannot explain the one-target advantage in rapid aimed hand movements.
Marianne Biegstraaten1, Jeroen B J Smeets, Eli Brenner
1Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands. m.biegstraaten@erasmusmc.nl
Human Movement Science
|September 12, 2003
Summary
The "one-target advantage" shows faster pointing movements when stopping at one target versus two. This study rejected the mechanical hypothesis, suggesting non-mechanical factors influence movement speed.
Area of Science:
- Motor control
- Human movement science
- Biomechanics
Background:
- Pointing movements are faster when stopping at a single target compared to reaching a second target, a phenomenon known as the "one-target advantage."
- Previous hypotheses suggested mechanical factors, specifically impact forces at the target, contribute to this speed difference.
Purpose of the Study:
- To investigate the mechanical hypothesis explaining the one-target advantage in pointing movements.
- To determine if larger impact forces at the first target are associated with the one-target advantage.
Main Methods:
- A minimum-jerk model was used to simulate smooth movements, predicting effects of larger contact forces.
- Experimental data on pointing movements were collected and analyzed, comparing one-target and two-target conditions.
- Key kinematic variables, including peak velocity and time of maximum velocity, were measured.
Main Results:
- The one-target advantage was experimentally confirmed, with faster overall movement times.
- Contrary to the hypothesis, the horizontal force at contact with the first target was not significantly larger in the one-target condition.
- Maximum velocity was higher in the one-target condition, but the time to reach maximum velocity did not differ significantly.
Conclusions:
- The mechanical hypothesis, positing impact forces as the cause of the one-target advantage, was rejected.
- The findings suggest that non-mechanical factors, such as cognitive or attentional processes, are more likely explanations for the observed one-target advantage in pointing movements.