Christopher Parisien, Charles H. Anderson, and Chris Eliasmith. Solving the problem of negative synaptic weights in cortical models. Neural Computation, 20:1473-1494, 2008.
@article {parisien2008,
title = {Solving the problem of negative synaptic weights in cortical models},
journal = {Neural Computation},
volume = {20},
year = {2008},
pages = {1473-1494},
author = {Christopher Parisien and Charles H. Anderson and Chris Eliasmith},
pdf = {http://compneuro.uwaterloo.ca/files/publications/parisien.2008.pdf}
}