If you haven’t gone over to The Brains Blog to view the Mind & Language symposium on Jean-Rémy Martin and François Le Corre’s “Sensory Substitution Is Substitution,” part of the journal’s April 2015 issue, you should. It’s an interesting perspective on what we normally think of as our other senses compensating for the lack of vision. Highly technical, this article and the subsequent symposium present the argument that the type of information processed by a SSD is metamodal and that the phenomenology is best described in terms of spatial phenomenology, only.
In addition, it also has been shown that they [the Vertical-Horizontal Illusion and the Ponzo Illusion] are equally and identically present in early blind people and that they usually depend on the same modulating factors as in vision (Gentaz and Hatwell, 2004).
If you’re interested in the entire article, you can view it on the Wiley Online Library, free through June 15th. Check out the symposium to get join the conversation on the topic.