Mixed Signal Learning by Spike Correlation Propagation in Feedback Inhibitory Circuits
Fig 3
Lateral inhibition is strong, fast, and sharp.
(A) Nullclines of the average synaptic weight changes at different inhibitory amplitudes wZ = 0.1, 0.215, 0.4. The inset in the middle graph is a magnified view of boxed area. (B) Specialization indices wSI for various inhibitory weights. Positive wSI indicates the winner-share-all state, whereas negative wSI indicates the winner-take-all state. Blue lines are analytical estimations and cyan squares are the results of simulations. Vertical lines correspond to the values at which the nullclines in Figure A are calculated. (C) The same graphs for various synaptic delays. The average synaptic delay of both lateral excitatory (dYmin+dYmax)/2 and inhibitory (dZmin+dZmax)/2 connections was changed, while the variability was kept at dYmax—dYmin = dZmax—dZmin = 1.0 ms. (D) IPSP rise time dependence. The inset shows IPSP curves at {τZA, τZB} = {0.5, 2.5} (gray line), {1.5, 7.5} (dark gray line), and {2.5, 12.5} (black line).