Preliminary study of t0 , a sigma-lognormal parameter extracted from young children’s controlled scribbles
Résumé
This work deals with the interest of using the sigma-lognormal model for the analysis of children graphomotricity. The sigma-lognormal paradigm defines a complex movement as an optimal sequential combination of elementary lognormal movements more or less superimposed which are sequentially triggered by the central nervous system. Assuming the validity of this postulate in the case of children’s controlled scribbles, this preliminary work investigates the distribution of the values of the parameter t0 with regard to the lognormal strokes that contribute to the reconstruction of scribbling movements. We consider two types of controlled scribble: the spontaneous and the curvilinear ones. Our exploratory approach shows that, globally and regardless of the scribble type, the values of t0 are mainly concentrated at the beginning of the onset phase of the previous elementary movement, that is at the beginning of the ascending period of its associated lognormal. Moreover, there is a localization prevalence of the t0 values on the contiguous previous elementary movement.