Gärdenfors has a book “Conceptual Spaces” which I haven’t got around to reading yet (it’s not on the ultrapriority queue, only on the normal priority queue 
)
The blog entry below has a few links to the central concepts of Gärdenfors’ theory. I agree with the need for integrating different levels (symbolic, connectionist and spatial in Gärdenfors’ version), but I think that ultimately one will need even more levels of modelling to capture thought processes.
Thought, I think, is the result of a veritable holarchy (thanks to Glen E. Ropella for alerting me to this concept in a mailing list discussion) of simultaneous processes in the brain with feed-forward and feed-back cycles. The holarchy would be made up of neuronal aggregates forming and breaking up spontaneously (within but also crossing modular boundaries).
The holarchy concept merits a post of its own – sometime 
