Independent Subspace Analysis and Topographic ICA
Read this paper about ISA: http://www.cs.helsinki.fi/u/ahyvarin/papers/ESANN06.pdf

and this one about topographic ICA: http://www.cs.helsinki.fi/u/ahyvarin/papers/NC01_TICA.pdf

Hyvärinen is the author of the FastICA algorithm.

PS. 

By the way, you might want to look at ICASSO (http://research.ics.aalto.fi/ica/icasso/), if you are not already familiar with it.