For the testing purpose, I set the number of neurons low and manually set the intercept, maximum rates and encoder values manually for each neuron. This gave the same weights and bias for each neuron for every simulation.
Then I noticed that even when each neuron has the same weights and bias for every simulation, the membrane voltage for each neuron were not identical for every simulation when I was probing. (different membrane voltages for each neuron at the time step).
I thought it was because the initial membrane voltage were different and the seed parameter got something to do with this. But from your response, the seed seems to be used in the generation of the gain and bias values rather than the initial state of the neurons. Does that mean if you set the intercepts and max rates yourself, just like what I did, so that you force Nengo to generate the same weights and bias for each neuron every time, the seed parameter does not matter much?
Thank you for your answer btw. I have less coding background and I am trying to learn Nengo. Some questions I ask might sound silly.