Editing Hopfield network (section)

===Neurons "attract or repel each other" in state space ===
The weight between two units has a powerful impact upon the values of the neurons. Consider the connection weight <math>w_{ij}</math> between two neurons i and j. If <math>w_{ij} > 0 </math>, the updating rule implies that:
* when <math>s_j = 1</math>, the contribution of ''j'' in the weighted sum is positive. Thus, <math>s_{i}</math> is pulled by ''j'' towards its value <math>s_{i} = 1</math>
* when <math>s_j = -1</math>, the contribution of ''j'' in the weighted sum is negative. Then again, <math>s_i</math> is pushed by ''j'' towards its value <math>s_i = -1</math>

Thus, the values of neurons ''i'' and ''j'' will converge if the weight between them is positive. Similarly, they will diverge if the weight is negative.