Sources of variability in interceptive movements.
In order to successfully intercept a moving target one must be at the right place at the right time. But simply being there is seldom enough. One usually needs to make contact in a certain manner, for instance to hit the target in a certain direction. How this is best achieved depends on the exact task, but to get an idea of what factors may limit performance we asked people to hit a moving virtual disk through a virtual goal, and analysed the spatial and temporal variability in the way in which they did so. We estimated that for our task the standard deviations in timing and spatial accuracy are about 20 ms and 5 mm. Additional variability arises from individual movements being planned slightly differently and being adjusted during execution. We argue that the way that our subjects moved was precisely tailored to the task demands, and that the movement accuracy is not only limited by the muscles and their activation, but also-and probably even mainly-by the resolution of visual perception.
Brenner
Eli
E
Faculty of Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands. e.brenner@fbw.vu.nl
Smeets
Jeroen B J
JB
D001288:Attention / Q000502:physiology*; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D005133:Eye Movements / Q000502:physiology; D007839:Functional Laterality; D006801:Humans; D008954:Models, Biological; D009039:Motion Perception / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013647:Task Performance and Analysis