Average synaptic weights as a function of the number of training trials.

<p>Average synaptic weights for three different connection types: feedforward (squares), feedback (circles) and recurrent (upward triangles) as a function of the trial number for temporally symmetric form of STDP ( and ms) (a) and for temporally asymmetric form of STDP ( and ms) (b). The other parameters are the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0084644#pone-0084644-g002" target="_blank">Fig. 2</a> except for ms. Also, we show the average synaptic weights for the connections including both feedforward and feedback types (downward triangles) in (a) and (b).