a structured survey. In S. Artemov, H. Barringer, A. S. d'Avila Garcez, L. C. Lamb, and J. Woods., edi- tors, We Will Show Them: Essays in Honour of Dov Cabbay, volume 1, pages 167-194. College Publications, 2005. Bi01. M-m Si, G-q andPoo. Synaptic modifications by correlated activity: Hebb's postulate re