I recently came across the work of Stephen Downes who works for the National Research Council of Canada. He and his fellow colleagues seem to be developing a theory of cognition that could support how and why concept mapping works in learning environments. To summarize:
Connectivism is the thesis that knowledge is distributed across a network of connections, and therefore that learning consists of the ability to construct and traverse those networks. The build of this work is devoted to tracing the implications of this thesis in learning.
I would welcome perspectives from the VUE community not just about Downes but how we think of the theoretical underpinnings of concept mapping. I would further distinguish between paper and pencil mapping vs. digital forms and if this has been investigated by anyone.