Liquid State Machine: How it works and how to use it?

Question

I am now learning about LSM (Liquid State Machines), and I try to understand how they are used for learning.

I am pretty confused from what I read over the web.

Answer 1

To understand LSMs you have to understand the comparision with Liquid. Regard the following image:

• You are randomly throwing stones into water. Depending of what kind of stones you have throwed into the water, there's another wave pattern after x timesteps.
• Regarding this wave pattern you can have conclusions about the features of the different stones
• Out of this pattern you can tell what kind of stones you threw in.

The LSM models this behavior we have:

• A input layer which is randomly connected to the reservoir of neurons. Take it as the stones you throw into the water

• A reservoir of randomly connected neurons. Those represent your Water which interacts with your stones in a specific way.

  • In terms of LSM we have special Neurons (they try to model real neurons). They add activations over the timesteps and only fire if a certain amount of activation is reached, a cooldown factor representing the natrium kalium pumps in the brain is applied in addition.
  • After x timesteps you'll have a pattern of spiking neurons at that time.

• A output layer which interprets that pattern, and uses it for classification.