STDP changes the relation between the time delay <i>τ</i> and the synaptic weights.

<p>STDP promotes zero-lag synchronization (<i>τ</i> ≈ 0): (a)-(c) <i>τ</i> as a function of the initial excitatory weights <math><mrow><msubsup><mi>g</mi><mrow><mi>M</mi><mi>S</mi></mrow><mn>0</mn></msubsup></mrow></math> with and without STDP (represented by circles and squares, respectively). (d)-(f) <i>τ</i> as a function of the inhibitory weights <i>g</i>_<i>IS</i> with and without STDP. (g)-(h) <i>τ</i> (color coded) in the (<i>g</i>_<i>IS</i>, <math><mrow><msubsup><mi>g</mi><mrow><mi>M</mi><mi>S</mi></mrow><mn>0</mn></msubsup></mrow></math>) parameter space without plasticity (g) and with STDP (h). The near-zero-lag regime is represented by the grey regions, AS (<i>τ</i> < 0) by the red regions and DS (<i>τ</i> > 0) by the blue ones. In the presence of STDP, <i>τ</i> is determined by the local amount of inhibition <i>g</i>_<i>IS</i>.