Difference between brain and electronic device signals As I understand it, a brain communicates through sending signals via ions and chemical reactions resulting in concentrations of ions, a computer sends signals by electrons.  I'm really trying to do 3 things:


Confirm that understanding
Understand what is the fundamental difference between the two types of signaling.  
Is there more to what the brain is doing at least at a relatively macro level that I may be missing.
This is a pretty broad question, however I think it's common enough that I think it's worth trying to answer. I'll break it down into the following:


What signals do the brain send?
How are these signals different than electronic signals?


1. Brain Signals

The brain has a lot of different signaling modalities. Some fast acting, some slow acting. Mostly, neurons communicate with the ions/chemicals you've mentioned above, which are actually called neurotransmitters.

2. Brain Signals vs. Electronic Device Signals

Spikes vs. Pulses

Electronic devices communicate by raising a potential on a wire and wait for the target of the communication to receive that pulse. The pulse can either be on or off. Neurons communicate via spikes, where the information is not "on" or "off", but also the frequency of the spikes and the spacing between the spikes.

Localised vs. Variable scopes

Electronic device pulses have clearly defined destinations. Although neurotransmitters can target a specific neuron, they can also modulate a group of neurons. This is called neuromodulation.

Static vs. adaptive

The wires on an electronic device do no change in strength. However, there are a TON of mechanisms for how the brain learns. The brain's "wires" called synapses, change in their effectiveness of transmission over time. The neurons themselves change in receptivity over time.

The Brain is not a Computer

To summarize, a computer or other electronic device is a really poor metaphor for the brain. I discuss this in my blog post "Understanding the Brain: Where Metaphors Limit You" if you would like a more in depth discussion on the subject.