The contribution deals with problems that make analysing linguistic areas in East-Central Europe, as the result of pluridimensional, polycentric convergence phenomena, a real challenge. It demonstrates why we still must investigate further into the contribution of specific groups of people to the emergence of certain areas in order to gain a better understanding of linguistic areas, especially in East-Central Europe. Furthermore, it also shows that in this context it seems more appropriate to speak of polycentric rather than pluricentric convergence. Whereas a pluricentric language is the sum of its varieties, a polycentric language according to Li/Juffermans (2012, p. 77) is “a dynamic, socially ordered system of resources and norms that are strongly or weakly associated with one or more centers”. As we could see from the example of their different evolution and his-tory, signed languages are not so tied to the spoken languages of a region, but rather to a place or a social stratum. This fact makes the concept of linguistic areas appear even more vivid and dependent on social interaction rather than on the specific characteristics of the languages in contact: Languages do not converge by themselves, it is the behaviour of the speakers that brings about these pluridimensional, polycentric convergence phenomena leading to specific linguistic areas.