Affine invariance of human hand movements: a direct test
نویسندگان
چکیده
Geometrical invariance, in particular affine invariance, has been recently proposed as an important principle underlying the production of hand movements. However, tests of affine invariance have traditionally been applied to the consequences of this principle rather to the principle itself. Here, we designed and performed an original, direct, test of affine invariance in a scribbling experiment. In each of the 10800 pairs of randomly-selected scribbling segments, we compared the time parameterizations obtained by transforming the first segment using four different transportation rules – affine, equi-affine, Euclidian and constant – with the experimentally-observed parameterization of the second segment. We observed that, when the two paths are affinely-similar, the affine transportation of the first segment yields the time parameterization that best matches the experimental parameterization of the second segment, which directly demonstrates the existence of affine invariance in the production of hand movements.
منابع مشابه
Eu – Fp7
A recent study has shown that geometrical invariance can describe the kinematic features of human drawing and locomotion movements [1]. The proposed theory has suggested that movement duration and compositionality arise from the cooperation among the Euclidian, equi-affine and full affine geometries. On the other hand, past studies have shown that different optimization principles can be used t...
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