According to the Hebbian Rule synapses increase their efficiency if the synapse persistently causes the postsynaptic target neuron to generate action potentials. An often used but not entirely accurate simplification is those who fire together, wire together. With recent advancements in technology we can more precisely measure the spike timing of neurons. As it turns out, the synaptic connection between two neurons is more likely to strengthen if the presynaptic neuron fires off shortly before the postsynaptic neuron. Revisiting, the Hebbian rule, we can tweak it to accommodate the new model. Synapses increase their efficacy if the presynaptic neuron is activated momentarily before the postsynaptic neuron is activated. OR Synapses in which the pre-synaptic input fired before the postsynaptic cell get stronger; in the inverse situation, the synapse gets weaker.