Network
Networks
are built by creating neurons and connecting them with synapses. They
are run by pressing the "play" or "step" button (see the quick reference). For a sense of what
the colors, circles, etc. signify see the discussion of visual conventions.
There are a variety of different neurons and synapses, each with their own rules and parameters. By combining these together you can create indefinitely many different kinds of networks. There are also special types of networks called "subnetworks" which can be added to a simulation. Different subnetworks can be linked together, leading to even more complex and powerful simulations.
There are also connection objects, layout objects, model groups and
other functions which can be used to build neural networks.
Shown below is a simple neural network. The colored circles with numbers in the middle represent simplified neurons or "nodes." The lines between nodes represent synaptic connections between neurons which direct the flow of activity in the network. The smaller blue and red discs at the ends of these lines represent synaptic connections.
When
Simbrain is first opened nothing happens. A sample network sits
passively before the user. When the user "runs" the network it comes to
life--an update algorithm is
repeatedly called, which is visible in the form of spreading activity
in network's nodes and (if learning is activated) changing weight
sizes. The network can be run by pressing pressing the play button in the tool-bar to
repeatedly iterate the network. Note that the image on the button
becomes that of a "stop" button
.
Pressing this button will stop the network. Thus the play/stop button
acts as a toggle switch. You can also press the step button
(or press "space") to iterate the network a single time. Sometimes
repeatedly hitting the space bar is useful way to test a network.