Name
Abstract | ||
|---|---|---|
The two-thirds power law, an empirical law stating an inverse non-linear relationship between the tangential hand speed and the curvature of its trajectory during curved motion, is widely acknowledged to be an in- variant of upper-limb movement. It has also been shown to exist in eye- motion, locomotion and was even demonstrated in motion perception and prediction. This ubiquity has fostered various attempts to uncover the origins of this empirical relationship. In these it was generally at- tributed either to smoothness in hand- or joint-space or to the result of mechanisms that damp noise inherent in the motor system to produce the smooth trajectories evident in healthy human motion. We show here that white Gaussian noise also obeys this power-law. Anal- ysis of signal and noise combinations shows that trajectories that were synthetically created not to comply with the power-law are transformed to power-law compliant ones after combination with low levels of noise. Furthermore, there exist colored noise types that drive non-power-law trajectories to power-law compliance and are not affected by smoothing. These results suggest caution when running experiments aimed at veri- fying the power-law or assuming its underlying existence without proper analysis of the noise. Our results could also suggest that the power-law might be derived not from smoothness or smoothness-inducing mecha- nisms operating on the noise inherent in our motor system but rather from the correlated noise which is inherent in this motor system. |
Year | Venue | Keywords |
|---|---|---|
2005 | NIPS | motion perception,motor system,white gaussian noise,power law,colored noise |
Field | DocType | Citations |
Colors of noise,Motion perception,Control theory,Computer science,Smoothing,Smoothness,Empirical relationship,Additive white Gaussian noise,Trajectory,Gradient noise | Conference | 4 |
PageRank | References | Authors |
0.50 | 0 | 4 |
Name | Order | Citations | PageRank |
|---|---|---|---|
| Uri Maoz | 1 | 4 | 1.17 |
| Elon Portugaly | 2 | 286 | 25.89 |
| Tamar Flash | 3 | 167 | 38.81 |
| Yair Weiss | 4 | 10240 | 834.60 |